David J. Peterson Mechanical Option “Thesis Report” · 2004-05-12 · Lighting: · Fluorescent...

David Peterson INOVA Fairfax Hospital Penn State AE, Mechanical The INOVA Heart Institute

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David J. Peterson Mechanical Option “Thesis Report” The INOVA HEART INSTITUTE AT INOVA Fairfax Hospital, Falls Church, VA.

Thesis Report

“Exploring New Technologies to Optimize Design ”

Instructor: Dr. Srebric

May 5, 2004

Thesis Building Sponsor’s:

INOVA Fairfax Hospital www.inova.com

& Turner Construction

3300 Gallows Road, Falls Church, VA 22042

www.turnerconstruction.com

David J. Peterson MECHANICAL OPTION www.arche.psu.edu/thesis/2004/djp196

INOVA Fairfax Hospital’s INOVA Heart Institute Falls Church, VA

The INOVA Heart Institute project consists of a 156 beds, 6 operating rooms, five-story structure, 440,000 sq. ft., located on the west side of the INOVA Fairfax Hospital and adjacent to the existing outpatient surgery building. The current facility and new addition are owned by the INOVA Health System. The overall cost is approximately $80 million and it is currently under construction and is due to open in the Summer of 2004. Design and Construction Team: General Contractor: Turner Construction Architects: Wilmot/Sanz, Inc. Landscape Architects: Lewis Scully Gionet MEP Engineer: RMF Engineering, Inc. Civil Engineer: Dewberry & Davis Structural Engineer: Cagley & Associates

Architectural Features: · Upon opening the INOVA Heart Institute will offer unique features designed to create a soothing and peaceful healing environment aimed at enhancing the recovery process for heart patients. · The use of soft lighting, wood accents, gardens, water and quiet/meditation areas will be woven throughout the Institute, contrasting with the stark clinical setting of traditional hospitals. · A three story front entrance Atrium will greet its visitors and patients. · The perimeter walls are a combination of insulated glass and either brick façade for the main levels, precast concrete curtain walls for the lower sub- level/garage, an aluminum panel wall system for the upper penthouse.

Electrical System: · Normal power will be derived from Virginia Power. · Emergency power will come from separate backup generating system. · Isolation Power will be provided to labs and Eps. · Grounding system using grounding grid to include each room along with lighting protection system which will rely on separate down leads other than structural steel. · Telephone and Data system will be provided via raceway system and allow for a means to wire outlets throughout the building. · Sound and paging system located throughout corridors and staff areas.

Structural System · Poured concrete column and concrete beam system · Floors are steel framed with poured cast in place concrete slab · The roofing system will include a primary cast in place concrete slab.

Mechanical System Features: · Constant Volume System for the operating, intensive care, patient, and clean work areas with 95-99% efficiency final filters · Variable Volume System for the Atrium and open waiting areas · Secondary low temperature cooling system loop for the Cardio Vascular Operating Rooms (CVOR) · Medical gas piping to each patient, operating, holding and prepping space · 13 AHU (3 on stand-bye) with total building SA of approx: 330,000 CFM

Lighting: · Fluorescent lighting will be provided throughout the entire project to provide energy efficiency in Mechancial/Electrical, corridor, and storage Spaces. · Dimming of fluorescents troffers will be used in special applications throughout to achieve appropriate lighting conditions in labs, patient, and operation rooms. · Incandesencents and other specialty lighting will be used in selected areas to achieve specific lighting effects along with task lighting, where necessary.


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Table of Contents: Search by Topic: 1.0 Executive Summary:......................................................................................... 5 2.0 Background: ...................................................................................................... 7

2.1 Building Information .................................................................................................................................8 2.2 Systems Design .........................................................................................................................................9 2.3 Design Requirements...............................................................................................................................10 2.4 Systems Information................................................................................................................................10 2.5 Indoor Design Conditions........................................................................................................................10 2.6 Outdoor Design Conditions .....................................................................................................................10 2.7 Utility Rates and cost factors...................................................................................................................11 2.8 Air Systems .............................................................................................................................................11 2.9 Steam Systems.........................................................................................................................................12 2.10 Hydronic systems ..................................................................................................................................12 2.11 Systems Costs........................................................................................................................................13

3.0 Air Distribution Analysis (Depth Study): ..................................................... 14 3.1 Background .............................................................................................................................................15 3.2 Problem ...................................................................................................................................................15 3.3 Proposed Solution....................................................................................................................................15 3.4 Plan of Attack..........................................................................................................................................16 3.5 Contaminates ...........................................................................................................................................17

3.5.1 Contaminates; Pathogens .......................................................................................................17 3.5.2 Contaminates; Types ..............................................................................................................17 3.5.3 Contaminates; Classifications ................................................................................................17 3.5.4 Contaminates; Droplet Production .........................................................................................18 3.5.5 Contaminates; Droplet Detection ...........................................................................................18 3.5.6 Contaminates; Droplet Evaporation .......................................................................................18 3.5.7 Contaminates; Transmission ..................................................................................................19 3.5.8 Contaminates; Routes of Infection .........................................................................................20 3.5.9 Contaminates; Dose................................................................................................................20 3.5.10 Contaminates; Viability........................................................................................................21 3.5.11 Contaminates; Nosocomial...................................................................................................21 3.5.12 Contaminates; Mechanical System.......................................................................................22

3.6 Controlling Contaminates: General .........................................................................................................22 3.6.1 Controlling Contaminates; Dilution Ventilation ....................................................................23 3.6.2 Controlling Contaminates; Displacement Ventilation............................................................24 3.6.3 Controlling Contaminates; Pressure: Difference....................................................................24 3.6.4 Controlling Contaminates; Room Air Cleaning Devices .......................................................24

3.7 Respiratory System..................................................................................................................................25 3.8 Air Quality Indicators..............................................................................................................................27 3.9 Introducing spaces ...................................................................................................................................29 3.10 Simulation Conditions ...........................................................................................................................30

3.10.1 Simulation Conditions “Family Waiting Room” .................................................................31 3.10.2 Simulation Conditions “Post Anesthesia Care Unit” .........................................................32 3.10.3 Simulation Conditions “Transplant Waiting Room” ...........................................................33 3.10.4 Simulation Conditions Validating Case: “CCC Hospital’s Surgical Waiting Room”.........34

3.11 Normalized Age of Air Simulation........................................................................................................35 3.11.1 Normalized Age of Air Simulation “Family Waiting Room” .............................................36 3.11.2a Normalized Age of Air Simulation “Post Anesthesia Care Unit” ....................................37 3.11.2b Normalized Age of Air Simulation “Post Anesthesia Care Unit” ....................................38 3.11.3 Normalized Age of Air Simulation “Transplant Waiting Room” .......................................39 3.11.4 Normalized Age of Air Simulation, Validating Case: “CCC Hospital’s

Surgical Waiting Room” ..................................................................................................40 3.11.5 Normalized Age of Air Simulation, Regions of Most Concern ...........................................41 3.11.6 Normalized Age of Air Simulation, Closer look at Transplant Waiting

Room.................................................................................................................................41


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3.12 Contaminate Removal Effectiveness, 100% Contamination Simulation...............................................43 3.12.1 CRE , 100% Contamination” Family Waiting Room” .......................................................44 3.12.2a CRE , Non-Patient Contamination “Post Anesthesia Care Unit”.....................................45 3.12.2b CRE , Patient Contamination “Post Anesthesia Care Unit” ............................................46 3.12.3 CRE , 100% Contamination “Transplant Waiting Room” ..............................................47 3.12.4 CRE, 100% Contamination, Validating Case ......................................................................48 3.12.5 CRE, 100% Contamination Simulation, Regions of Most Concern.....................................49 3.12.6 CRE, 100% Contamination Simulation, Closer look at Transplant Waiting Room.............51 3.12.7CRE, 1 Person Contamination Simulation, Closer look at Transplant Waiting Room .........51 3.12.8 Determining the Duration of time for Steady State Conditions to Occur.............................52

3.13 1st Proposed Solution.............................................................................................................................53 3.13.1 1st Proposed Solution, CRE, 100% Contamination ............................................................................54

3.13.2 1st Proposed Solution, Normalized Age of Air.....................................................................55 3.13.3 1st Proposed Solution, CRE, One person Contamination .....................................................56

3.14 2nd Proposed Solution ............................................................................................................................57 3.14.1 2nd Proposed Solution, CRE, 100% Contamination .............................................................58 3.14.2 2nd Proposed Solution, Normalized Age of Air ....................................................................59 3.14.3 2nd Proposed Solution, CRE, One person Contamination ...................................................60

3.15 Proposed Solutions, Cost Estimate ........................................................................................................60 3.16 Summary ...............................................................................................................................................61

4.0 Constructability Analysis (Breadth Study): ................................................. 63 4.1 Background .............................................................................................................................................64 4.2 Introducing the Space ..............................................................................................................................64 4.3 Problem ...................................................................................................................................................64 4.4 Plan of Attack .........................................................................................................................................65 4.5 Investigation of Upper Plenum Space .....................................................................................................65 4.6 3D Coordination Section Before Redesign..............................................................................................66 4.7 Schedule, Sequencing of Trades..............................................................................................................67 4.8 3D Coordination Section After Redesign ................................................................................................67 4.9 Impact of Redesign..................................................................................................................................68 4.10 Summary ...............................................................................................................................................68

5.0 Daylighting Analysis (Breadth Study) .......................................................... 69 5.1 Background .............................................................................................................................................70 5.2 Introducing the Space ..............................................................................................................................70 5.3 Problem ...................................................................................................................................................70 5.4 Plan of Attack..........................................................................................................................................71 5.5 Determination of Optimal glazing...........................................................................................................71 5.6 Daylight Simulations ...............................................................................................................................72

5.6.1 Daylight Simulations, Daylight Factor...................................................................................72 5.6.2 Daylight Simulations, AGI.....................................................................................................73

5.7 Building Loads and Operating Cost ........................................................................................................79 5.8 Impact on Exterior Façade .............................................................................................................80 5.9 Cost Analysis .....................................................................................................................................81 5.10 Feasibility of Results .............................................................................................................................82 5.11 Summary ...............................................................................................................................................82

6.0 Conclusions: ..................................................................................................... 84 7.0 Credits and Acknowledgements: ................................................................... 86 8.0 References:....................................................................................................... 88 9.0 Appendix:......................................................................................................... 91

9.1 Appendix A.1 ..........................................................................................................................................92 9.2 Appendix B.1.........................................................................................................................................105


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1.0 Executive Summary:

The purpose of this report is to investigate the problematic distribution of

contaminates with in existing spaces(Depth), constructability of proposed solutions to the air

distribution systems(Breadth), and the optimization of natural daylighting(Breadth) for the

INOVA Heart Institute. The new INOVA Heart Institute is an addition to the INOVA

Fairfax Hospital (existing) in Falls Church, VA, The overall size of the new addition to the

original hospital is approximated at 410,000ft^2 of which 300,000ft^2 is conditioned.

In the depth study by using computational fluid dynamics it was determined that there

were regions of concern in multi-occupied spaces where high concentrations of contaminates

could collect and pose a threat to the inhabitants within those spaces. The types of spaces

investigated include waiting rooms and recovery rooms. Proposed solutions suggested that

changing the current air distribution system at minimal cost to the owner could drastically

reduce concentration levels.

In the first breath study on constructability, proposed solutions to the depth study

were investigated for feasibility of implementation. When changing air distribution systems

other problems may arise when actual renovation take place. Because of this the upper

plenum space above the room must be investigated for possible obstructions and hazards

posed by the redesign. The results of this investigation suggested that if the redesign was

implemented either before or after the actual design that there would be no major issues and

that constructability was possible.

The second breadth study investigated the optimization of natural daylight with the

mechanical system. It was determined that INOVA Heart Institute has a very large quantity

of glazing on its exterior surfaces of which exposure to natural light was rather large. By

investigating passive solar architecture design, along with recommended natural daylight

illuminace values it was determined that exterior glazing area could be reduced which would

have a positive impact on annual mechanical operating costs. With the change in window

area on the exterior walls associated impacts on the non-load bearing curtain wall were also

investigated. Cost of implementation was also included in this study.

The INOVA Heart Institute final rendering is shown in the photo on the following

page below courtesy of Turner Construction and is due to open in the summer of 2004.


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INOVA Rendering 1: “Final Rendering”


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2.0 Background


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2.0 Background: 2.1 Building Information

The INOVA Heart Institute is an addition to the existing INOVA Fairfax Hospital. It

is located in Northern Virginia just outside of the 495 Beltway in Falls Church, Virginia. As

stated in its name the new addition will serve as a Cardio-Vascular Institute and provide

Operating, Care, Rehabilitation and lab spaces for all issues dealing with the heart. The

demand for such facilities is ever increasing with the explosion in population in the Northern

Virginia Area. The overall size of the new hospital is approximated at 410,000 sq.ft. with 6

floors, 360,000 sqft of condition floor space, 6 cardio vascular operating rooms, over 150

patient rooms, outdoor gardens, along with a garage (located in the basement).. The hospital

is broken down into 3 wings and are divided into sections A, B and C. Sections A and B

serve the majority of the hospital and serve as recovery, patient, lab, general hospital office,

atrium and recreation spaces. The third wing or CVOR (Cardio-Vascular-Operating-Rooms)

serves as the critical care and operation wing.

The new addition will be located and attached to the rear of the existing facility on the

west end of the property.

INOVA Photo 1: “Existing Hospital”

The new addition receives all its chilled water and high pressure steam from this

remote central plant which is fed into the building’s sub-basement via existing tunnels

adjacent to the existing hospital. The west end of the property was the only appropriate

direction in which to expand. The north end contains overflow parking a water tower and the

central plant. The existing hospital extends all the way to the property limits on the east end

next to Gallows Road, a major thoroughfare.


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INOVA Photo 2: “Aerial shot of Existing Hospital”

The INOVA Heart Institute is currently being constructed between the new parking

deck and the existing hospital.

INOVA Photo 3: “Existing Central Plant”

2.2 Systems Design The design for the mechanical systems for the new INOVA Heart Institute include:

1. Provide round the clock sufficient conditions for patients, workers and visitors

with the use of terminal duct reheats, steam humidification and critical sensors

throughout. (CO2, Temperature, and Pressure)

2. A variable volume system for variable occupancy in the open areas and atrium

space

3. A constant volume system for the typical hospital area

4. A system that ingrates with the existing facilities district chilled water, steam

and condensate

5. Provide backup AHU’s to each system in order to maintain sufficient conditions


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2.3 Design Requirements

The primary objective is to maintain sufficient condition for 24 hours of operation.

This requires proper filtration for indoor air quality issues, sufficient temperature, pressure,

and C02 levels. These requirements serve to protect the health and well being of the

inhabitants of the facility.

2.4 Systems Information

The mechanical systems for this hospital are a combination of constant volume and

variable volume with thirteen separate air handlers. Eight of these air handlers feed into four

main shafts that supply patient rooms and clinical areas for the entire building, two of which

are stand-bye. Three of these air handlers feed the Cardio Vascular Operating Rooms

(CVOR) on the 2nd and the area directly above on the 3rd floor, one of these is a stand-bye.

The last two of these feed the atrium and waiting areas.

2.5 Indoor Design Conditions The indoor air conditions are taken from the mechanical specifications and are

represented below. Indoor Air Conditions

Indoor design conditions for all areas excluding CVOR’s Dry Bulb: 72 F Relative Humidity: 50% Indoor design conditions for all areas including CVOR’s (Cardio-Vascular Operating Rooms): Wet Bulb: 65 F Relative Humidity: 50%

INOVA Table 1: Indoor Air Conditions

2.6 Outdoor Design Conditions The outdoor air conditions for design match that of the design conditions given in

ASHRAE’s Fundamentals for Washington, DC (at 0.4%) and are listed in the table to follow.

Outdoor Air Conditions Design Cooling Temperatures: (Summer) Dry Bulb: 95 F Mean Wet Bulb: 76 F Design Cooling Temperatures: (Winter) Dry Bulb: 15 F Evaporating Temperatures: Wet Bulb: 79 F Mean Dry Bulb: 89 F

INOVA Table 2: Outdoor Air Conditions


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2.7 Utility Rates and cost factors The following utility charges apply to the INOVA Heart Institute. The energy

sources for the new addition are electric power from Virginia Electric and Power Company

and gas from the Washington Gas and Light Company.

Virginia Electric and Power Company Schedule GS-3U Distribution Service Charges Basic monthly: $119.80 or $1437.60 annual Distribution Demand on all KW: $2.12 per KW Competitive Trans. On Peak Demand: $2.897 per KW Competitive Trans. On Peak KWH: $0.00568 per KWH

INOVA Table 3: Electric Rate Summary Under this rate schedule there is always a distribution demand on all KW but there

are no excess off-peak demand charges like there is for on-peak. Keeping this new facility on

the premises of the existing facility takes advantage of the no off- peak demand charge.

Washington Gas Commercial and Industrial Service Rate Schedule NO. 2 System Charge: $196.2 /(annual) Distribution Charge: (Per Therm) First: 125 Therms 0.3083/(mos.) Next: 875 Therms 0.2483/(mos.) Over: 1,000 Therms 0.1831/(mos.)

INOVA Table 4: Gas Rates Summary

On-peak hours are as follows: 1. For the period of June 1 through September

30, 10 a.m. to 10 p.m., Mondays through Fridays.

2. For the period of October 1 through May 31, 7 a.m. to 10 p.m., Mondays through Fridays.

Information for the gas boilers located in the central plant is not accessible. Savings

is obtained by the use of a central plant, which purchases this utility presumably in large

quantities to support the needs of the existing as well as the new facilities on the property.

2.8 Air Systems AHUs 1,2,3,4 and 7,8,9,10 serve patient rooms and general hospital Area (Constant

Volume System). For design conditions three air handlers are used to supply air into a

common duct, which then splits into two major shafts that run down the entire length of the


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building. The fourth unit (AHU-4) is connect to the same system and is for back up purposes

only.

AHUs 5 and 6 serve the atrium and lobby areas (Variable Volume System). For

design conditions the two air handlers are used to supply air into a common duct and supply

air to the front entrance atrium.

AHUs 11,12,13 serve Cardio Vascular Operating Room (CVORs) spaces and areas

directly above (Constant Volume System with Isolation Dampers). For design conditions two

air handlers are used to supply air into a common duct which only drops down two floors.

The third unit (AHU-13) is connect to the same system and is for back up purposes only.

AHUs Section System Type

Room SA (F):

CFM (each):

Outdoor Air (%):

Back-Up

Unit (AHU):

Cooling (Tons - each):

Cooling (Total Tons):

1,2,3,4 A CAV 55 40000 30 4 184 552

5,6 Atrium VAV 55 32000 30 - 144 288

7,8,9,10 B CAV 55 40000 30 10 184 552

11,12,13 C CAV 55 40000 30 13 184 368 INOVA Table 5: AHU Characteristics

AHUs Section System Type

Pre-Filter (%)

Post-Filter (%)

Final-Filter (%)

Post Final Filter (%)

AHU Location

1,2,3,4 A CAV 30 60 95 99.95 5th FL Penthouse5,6 Atrium VAV 30 60 - - 5th FL Penthouse7,8,9,10 B CAV 30 60 95 99.95 5th FL Penthouse11,12,13 C CAV 30 60 95 99.95 4th FL Penthouse

INOVA Table 6: AHU Filtration

2.9 Steam Systems The system brings in High Pressure Steam (HPS) from the central plant. The system

converts HPS into Medium pressure steam (MPS) and Low Pressure Steam (LPS) through a

network of Pressure Reducing Valves (PRV) that accommodates the various mechanical

equipment throughout the new facility.

2.10 Hydronic systems Hot water is provided to the building through a self-contained loop, which

uses steam/heating-water-converters or heat exchangers to produce hot water to re-circulate

through the building. The purpose of the hot water loop is to provide reheat to CAV and


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VAV terminal units and preheat to the AHUs and radiant panels. The facility has seven

major hot water pumps to perform this task.

Chilled water is provided to the building by the remote central plant, also the location

of the primary/secondary pumping. The purpose of the chilled water is to provide cooling for

coils located within the air handlers and fan coil units.

There is a secondary chilled water loop that serves the CVOR wing of the building.

Secondary chilled water supplied by two air-cooled chillers (50 tons each). The cooling coils

here are used to supply an air dry bulb temp of 42.3 F at an entering water temperature of 38

F to the operating spaces.

2.11 Systems Costs:

The following mechanical system costs, supply actual values for the all three wings of

the new hospital combined and they are further broken down into three main costs

Mechanical/ Plumbing/Medical Gas (combined), Sprinklers and Electrical. The system cost

represented show that the Mechanical overall cost is the most expensive per square foot of

the building.

System's Cost Type Cost ($) Cost/sq.ft. ($)Sprinkler 836,000 2.04*Mechanical 17,200,000 42.02Electrical 9,200,000 22.33

Total: 27,236,000 66.39

*(Includes all Mech., Plumbing, and Med. Gas )

INOVA Table 7: System’s Cost

The Overall cost for the building was $80 million per square foot the mechanical systems

make up approximately 21% of the overall cost of the entire building.


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3.0 Air Distribution Analysis (Depth Study)


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3.0 Air Distribution Analysis (Depth Study) 3.1 Background

Like most building applications, in health care facilities the most desirable manner of

introducing supply air to its spaces is to maximize overall distribution throughout theses

spaces. This is most important with critical environments such as hospitals because the

threat of disease and infection is more prevalent. Proper distribution and mixing of air

maximizes the effectiveness of ventilation and ensures that clean air is available everywhere

it is needed and eliminates stagnant air pockets.

Most often in building system design a simulated analysis of what actually occurs is

omitted. In the case of air distribution many negative effects can occur once the building is

completed and operating. In such buildings as hospitals these negative effects can attribute

to infection, sickness and even death.

Large multi-occupied spaces such as waiting rooms, intensive care units, and post

operating recovery rooms are suspect areas for airborne contamination. The primary method

of air borne contamination in these multi-occupied spaces is coughing and sneezing (person

expelling contaminants into open air). The primary reason for secondary contamination and

ultimate infection from patient to patient is due to improper placement of supply air

distribution diffusers and return air vents.

3.2 Problem Good air mixing is achieved by careful selection of diffuser location and

performance, with proper attention to room construction and/or perimeter exposures that can

affect distribution performance. The goal for this proposed solution would be to minimize

the spreading of secondary contaminates by reducing the overall concentrations, keeping

them localized, and ventilating them efficiently and properly. Proper design, placement, and

location of supply and return side diffuser/ventilation equipment can maximize air quality

while accruing no additional operating expenses or having any adverse effects on its

occupants. The impacts of this topic would require a study of systems equipment with

amount overall supply and return air quantities required to be distributed to each space as

well as studies of how supply and return air are supplied to each space. 3.3 Proposed Solution

The solution method for properly mixing and distributing air in multi-occupied spaces

within a hospital begins with the selection of suspect areas, which include intensive care


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units, recovery, and waiting rooms. Supply and return air quantities must be accurately

accounted for and defined for each space. Then all parameters effecting airflow in the space

must be defined these include location, orientation, and general obstructions. Once all the

space-defining characteristics have been determined Computational Fluid Dynamic (CFD)

simulation analyses will be preformed on each space to model flow patterns and assess each

rooms’ performance. Once simulations have been done and room performance has been

assessed decisions must be made on how much and where supply and return air distribution

equipment must be distributed/ventilate and where it will be located. Affects on the

relocation of diffusers and vents types with in the space must also be looked at. Simulations

will represent typical setting of people and their location in the room of interest. Developing

regions of most concern will be the focus for the simulations. The worst case scenario will be

simulated in order to see where low velocities, low flow and stagnant pockets exist.

The scale at which the simulations will be done and the density of the mesh of which

the simulations will calculate associated properties cannot fully show the effects of person-

to-person contamination, but can give insight on what may occur in the space. Inspiring and

expiring of air is a very difficult concept to model due to the relative nature of people and the

differences in each individual. Only speculation of effects from person to person

contamination within the space can be ascertained. The simulations do show the

development of concentrations at steady state in low velocity areas and low flow areas

produced by improper and or inadequate air distribution.

For the purpose of this study pockets and regions that are adjacent to doors (entrances

and exits) will not be considered. The reason for this is that people are not likely to remain

in these areas for durations of time which contaminate levels can develop in these areas flow

patterns will change regularly and steady state conditions will mostly like never be achieved

in these areas. Also open areas free of furniture and people or areas where people will most

likely not congregate will not be considered.

Regions will be considered threatening if air flow patterns yielded high age of air and

concentrations where air flow patterns were maintained for a period of time or long enough

to have a sustain concentrations levels greater then exhaust concentration.

3.4 Plan of Attack

1. Define Space Conditions through the design documents

2. Simulate models to meet initial thermal design conditions.


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3. Simulate and evaluate Indoor Air Quality Indicators

4. Determine regions of most concern

5. Propose solutions to rectify any problems

6. Re-simulate with proposed solutions.

7. Evaluate the solutions (cost, feasibility, and effectiveness)

3.5 Contaminates: In the field of Indoor Air quality very little research is available on the microbiology

aspect of this science. The lack of information on the transmission of pathogenic particles is

due to the fact that the “aerobiology” is misunderstood and that the “threat posed by such

airborne microbes is greatly underestimated.”(9) 3.5.1 Contaminates; Pathogens:

The pathogen term refers to any microorganism or agent that may cause disease or

irritation in the respiratory system. There are three types of respiratory pathogens: viruses,

bacteria and fungi. Less than two dozen pathogens account for the majority of contagious

infections. 3.5.2 Contaminates; Types:

Viruses are very small cell based parasites. The major viruses of concern include the

rhinovirus and influenza (approximate range of size is 0.03 to 0.2 um in diameter). Bacteria

are single celled microorganisms. The most common are TB, Legionella Pneumophila, and

Anthrax (approximate range of size is 0.2 to 3 um in diameter). Fungi can cause infection for

low immune systems can develop in HVAC systems and are a major concern in hospitals

(approximate range of size is 0.8 to 20 um in diameter). A chart showing Relative Size is

located in Appendix A.1. 3.5.3 Contaminates; Classifications:

There are three classifications that define all airborne pathogens communicable, non–

communicable, and nosocomial. When classifying respiratory pathogens the term

communicable is interchangeable with the term contagious. Communicable diseases are

disease mainly coming from humans. Non-communicable diseases are diseases derived from

the environment. Microbes that cause infection for people with low immune systems and or

people recovering in hospitals are known as nosocomial or hospital acquired infections.

These usually only occur when a person’s health is compromised. Appendix A.2 and A.3 has

a list of major respiratory pathogens classified into these three categories.


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3.5.4 Contaminates; Droplet Production: Respiratory pathogens can be transmitted through the exchange of infectious moisture

droplets or particles called droplet nuclei, which can easily spread, throughout the space. It is

said that a person in the infectious stage of a “cold may produce 6200 droplet nuclei per hour

of viable disease containing viruses that remain airborne longer than 10 minutes.”

A droplet nuclei is the remnants of an evaporated droplet expelled by a person

through the actions of coughing or sneezing, which can introduce pathogenic microbes into a

space. One microbe is equivalent to one colony forming unit or CFU. Sizes of a droplet

nuclei range from approximately 0.02 microns to 10 microns in size. Normal pathogenic

viruses range from 0.02 to 1 micron. One Micron has the density of approximately 1g/m^3.

A profile of particle sizes that an infections person can produce can be found in Appendix

A.4.

A single sneeze can generate a hundred thousand floating bioaerosol particles

containing viable microorganisms. A single cough typically produces about 1% of this

amount, but “coughs occur about ten times more frequently than sneezes.” Negligible

production occurs when talking. When a person sneezes or coughs many thousands of

droplets are vigorously expelled into the atmosphere. In the case of sneezing initial

velocities can be as high as 100 m/s. If droplet nuclei are produced by an infectious patient,

then they will contain pathogenic microorganisms which will be dispersed into the

atmosphere.

3.5.5 Contaminates; Droplet Detection: It is said that detection of viruses and bacteria is normally a time consuming

laboratory process, and is not always guaranteed to be successful unless one knows exactly

what one is looking for. Detection of airborne pathogens in an air stream is nearly

impossible, new technologies offer some promise but for now only can speculate on

simulated results. Knowing room and particle characteristics can simulate approximate

location. 3.5.6 Contaminates; Droplet Evaporation:

During sneezing most of the droplets are approximately 10 to 100 µm in diameter.

The larger droplets fall to the ground, while evaporation of the smaller droplets take place

and they rapidly decrease in size to become droplet nuclei.


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The precise rate of evaporation is dependent on the vapor pressure in the air which is

governed by its temperature and humidity. Because of this most of the droplets produced

by a sneeze quickly evaporate to form droplet nuclei and or single microbes. Droplet

nuclei are so small that they settle slowly and remain suspended in air for a

considerable period of time.

Diameter of Droplet (µm)

Evaporation Time (Seconds)

Distance that droplet will fall Before evaporation (m)

200 5.2 6.51 100 1.3 0.42 50 0.31 0.0255 25 0.08 0.00159 12 0.02 0.00008.5

INOVA Table 8: Water droplet Evaporation Time(9)

The previous table shows the evaporation times of water droplets and falling distance

before evaporation in air at 22C and 50 % relative humidity. Under calm conditions a 2um

particle would take approximately 4.4 hours to fall a distance of 2 m. Given this long

suspension time particles will be carried long distances by natural convection currents.

Depending on ventilation strategy and air distribution, droplet nuclei can travel even longer

distances and thus be widely distributed throughout the building space. A chart showing the

disappearance of airborne sneeze droplets after duration of time is located in Appendix A.7. 3.5.7 Contaminates; Transmission:

Microorganisms can enter the air by a variety of routes. The eyes and nasal passages

and mouth are vulnerable to microbial transmission. Contaminated skin cells, which are

continually shed by room occupants can also be a form of transmission. Most common

forms of transmission are touching contaminated surfaces or direct contact with person in

close range.

The approximate number of new infections can be calculated when knowing the room

ventilation rate. From this relationship it can be seen that with the increase in ventilation the

number of new infections will decrease.

Equation (1):

N =(S) x (1 – exp -((I) x (D) x (Qp) x (T) /(Qr)))

N = # of new infections S = # of susceptible I = # of infectors


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D = # of infectious doses Qp = pulmonary vent rate T = duration exposed Qr = room ventilation rate

3.5.8 Contaminates; Routes of Infection: “The airborne route of transmission is important for a number of pathogenic

microorganisms in hospital buildings. The airborne link in the ‘chain of infection’ associated

with diseases such as TB is the weakest ‘link’, and the one which gives hospital engineers

and health care authorities the best opportunity to break the chain. Through the use of well-

designed engineering systems it is possible to control the spread of airborne pathogens in

hospital buildings. There is a need to raise the general awareness of available

engineering control measures and to carry out research into the optimization of these

measures in healthcare facilities.”(9)

Displayed in Appendix A.9 is a chart that shows the route of infection of colds at

various doses. The results displayed in this chart show that the nose and the eyes are the

most vulnerable routes of virus invasion. Displayed in Appendix A.10 is a chart that shows

the typical source of the cold virus. 3.5.9 Contaminates; Dose:

Dose is the total mass of toxin subjected to body it is a function of airborne

concentration, duration of exposure and uptake efficiency. In general high concentration for

short time has high efficiency effect while low concentration long time low efficiency effect.

Determining the mass body of burden can be a helpful way of determining concentrations the

body has contained over a duration of exposure it is a function of the mass of a contaminate

contained, mass inhaled, Efficiency of absorption, and efficiency of elimination. Because

results from CFD analysis or at best only rough estimates the mass body of burden will not

be calculated for occupants receiving a concentration dose.

The dose received from an airborne concentration of microbes depends on the local

air change rate and degree of mixing as well as the generation rate. The successful

transmission of an infection, however, depends on all of the following factors: susceptibility

of the individual; duration of exposure; concentration of infectious agent; virulence of

infectious agent; breathing rate; route of infection The health and degree of immunity can be

as important as the dose received from prolonged exposure. Rate of infection can be useful


21

in determining risk assessment. A chart showing communicable respiratory infections and

rate of infection characteristics can be found in Appendix A.5.

The mean infection or incapacitating dose (ID50) it the dose or number of

microorganisms that will cause infections in 50% of an exposed population. Applies only to

microorganisms and units are always in terms of microorganisms or CFU or colony forming

units. (cfu/m^3) In Appendix A.12 the infectious dose curve for influenza (typical

pathogen) along with general information about the pathogen are listed. The following

equation can be used to calculate dose.

Equation (2):

.

Dt = Dose over duration of time Q = Pulmanary ventilation rate c = Concentration over time t = Duration of time

3.5.10 Contaminates; Viability: Various elements in the environment can destroy most airborne microbes. These

elements include: direct sunlight, dehydration, high temperatures, freezing temperatures and

oxygen(oxidation) in the environment will destroy most pathogens. Airborne microbes also

may lose viability over time in the absence of sunlight. Decay rate is subject to change given

actual conditions experienced in the space. A chart showing the viability of airborne

particles indoors after duration of time is located in Appendix A.6. 3.5.11 Contaminates; Nosocomial:

“Nosocomial infection or hospital originating infection is a major problem in many

healthcare facilities, with approximately 1 in 10 patients acquiring an infection during a

hospital stay.” (9) The economic impact of nosocomial infections is considerable and many

have become drug resistant.

Most nosocomial infections are direct or from person to person contact but can still be

transmitted through the airborne route. “It has been calculated that the airborne route of

transmission accounts for 10% of all sporadic cases of nosocomial infection.”(1)

All respiratory pathogens are potentially nosocomial. In intensive-care units and high

occupancy areas in hospitals, almost a third of nosocomial infections are respiratory.


22

Nosocomial infections can also be airborne but non-respiratory, such as when common

microbes settle in wounds typically resulting in post operating infections. Natural defenses

are usually compromised for individuals who succumb to nosocomial infections. All

respiratory pathogens are potentially nosocomial.

When concerning ventilation systems Humidity control is a very important issue in

hospitals because it prevents bacteria, mold and fungi growth and spreading throughout the

facility. Nosocomial infections can result in poor humidity control. 3.5.12 Contaminates; Mechanical System

Poorly designed or maintained mechanical ventilation systems can house and

distribute pathogenic contaminates. Elements in the ventilation system can be contaminated

with microorganisms that can spread fairly easily throughout the building

INOVA Rendering 2: Sources and pathways of microbial contamination

Cooling coils and humidifiers and low air velocities are all potentials for sponing

unwanted pathogenic contaminates such as Legionella Pneumophila. Even filters that are not

maintained and change regularly can become dirty, and they themselves can become

contaminated and can aid in the spread of airborne pathogens.

3.6 Controlling Contaminates: General: Ventilation systems in buildings are designed and operated to deliver fresh air to

occupants while removing internally generated contaminates to provide acceptable thermal

comfort levels in the vicinity of occupants. When designing ventilation systems the

emphasis is primarily on thermal comfort because quality perceived and judgment is much

larger and better defined by standards. On the other hand poor air quality response time is


23

much longer and not very well defined. The chain of infection is therefore very much

influenced by the ventilation conditions, which exist in any particular clinical setting.

When controlling airborne pathogens, good mechanical ventilation, or supply of clean

and or outdoor air, is probably the most effective along with efficient air movement

throughout space. Ventilation in hospitals is vital for contaminate control. Ventilation in

general is the supply of fresh air to a space to replace contaminated air that may dilute and or

displace contaminates. In large facilities such as the one explored in this study only about

30% outside air is introduced into the supply air. This means that high efficiency filters must

be used to prevent contaminate introduction through recirculated air, which is the case for

this building.

Air movement is crucial when trying to prevent contamination it is also a necessary

requirement for this type of facility in order to maintain spaces, with few or no stagnant air

pockets, increase thermal comfort, and achieve uniform humidity control.

In theory as clean ventilated air is introduced it will produces uniform concentration

of contaminants and it removes contaminated air at average concentration of the space or at

contaminate equilibrium. Contaminate equilibrium is a function of volume flow rate of clean

air, volume of the space and the rate at which contaminates are introduced into the space.

The following equations show this at well-mixed conditions.

Equation (3): Ceq = Cg/( AC) x (Vr) Ceq = Contaminate Equilibrium Cg = Rate of contaminate introduction in space AC = Number of air changes Vr =Room Volume

3.6.1 Controlling Contaminates; Dilution Ventilation:

contaminates effectively. Dilution ventilation is used most effectively in smaller spaces.

Dilution ventilation is the intentional mixing of large

quantities of clean/fresh air in a space. With good

conventional air distribution and properly designed

diffusers, dilution ventilation can achieve fairly well

mixed or ideal conditions for flushing out and removing


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Hospitals such as the INOVA Heart Institute use a combination of dilution ventilation

and pressurization with high air change rates. 3.6.2 Controlling Contaminates; Displacement Ventilation:

Laminar and displacement ventilation carefully directs airflows to displace

contaminated air. This type of ventilation introduces fresh air a low velocity, causing a piston

type effect for air towards return inlets, and causes non-uniform concentration of

contaminates in the space. Displacement ventilation can remove contaminates (2) times that of well mixed space

but stratification issues may cause adverse temperature and humidity conditions at different

altitudes and locations within the space. These types of systems are somewhat specialized

and are often used in clean rooms and operating rooms but are starting to be used more

commercially. In hospitals especially they are ideal in isolation environments and aid in the

prevention of nosocomial infections. Supply and return air vents are often at opposite ends

of room (i.e. air can be supplied at low levels and exhausted at high levels or vice versa)

3.6.3 Controlling Contaminates; Pressure: Difference: Pressure differences are used throughout the new facility to prevent contaminated air

from one zone or space to spread to another via doors and other means of indoor infiltration.

By controlling the airflows within a building it is possible to create ‘high’ and ‘low’ pressure

regions. Primarily used in isolation rooms to prevent airborne pathogens from escaping. A

major problem associated with pressurization is that of maintaining designed pressure at all

times in critical areas. Unfortunately the process pressure

difference does not prevent contaminates already within a space

from spreading into potentially susceptible areas also within that

space.

3.6.4 Controlling Contaminates; Room Air

Cleaning Devices:

There are a variety of room air cleaning devices

currently available, incorporating technologies such as high efficiency particulate air

(HEPA) filters, ultraviolet germicidal irradiation (UVGI) lamps, along with many others.

These devices are intended to be mounted within a room and designed to reduce the overall


25

microbial level in the room air. Strategically placed they are fairly efficient in protecting

hospital staff and patrons.

The efficiency of such filtration devices as HEPA filters, although as much as 99% its

overall room effectiveness may be much lower because compared to the entire space very

little air passes through the device. Again, when dealing with filters they must be maintained

and regularly changed/cleaned to prevent contamination and reduction in discharge rate.

The benefits of Ultraviolet Germicidal Radiation (UVGI) have been known for

nearly a century and can be used in many ways to disinfect air in buildings. They can be

installed in the air system itself or in actual spaces UV radiation can damage the DNA of a

microorganism and render it no longer viable as a pathogenic viral agent. Unfortunately UV

light is mostly used in upper air levels outside of a normal breathing plain in a space, as it can

be irritating and uncomfortable if exposed to for duration of time.

There are many other approaches in which engineers have proposed to reduce overall

contaminate concentrations and viability in a space of which only a few have been listed here

in this report.

3.7 Respiratory System “Protection for one by mechanism is the unfortunate exposure to another” through

means of coughing and sneezing resulting in the production of bioareosols in a space. The

single most important physical characteristic by which to classify airborne pathogens is size,

deposition of particles varies within the respiratory system. In general smaller particles

(viruses) tend to be more hazardous, more easily deposited into the lungs, harder to capture

by respiratory defenses. Due to lack of mass tend to stay suspended in air for extended

periods of time. A virus such as pathogenic influenza is approximately 0.1 um diameter and

settling time can take as much as 10 days. Fortunately viruses tend to die rapidly in air. A

chart on associated particle settling times based on diameter of particle is located in

Appendix A.8.

As stated previously bioaerosol /aerosol sources are a direct result of coughing,

sneezing, in the mechanical system, cooling towers and humidifiers. For the purpose of this

study only contaminates introduced by occupants will be considered. In general large

particles tend to deposit in the nasopharyngeal region. Smaller particles deposit in

pulmonary region. Deposition is not perfect and some inhaled will be exhaled. Bioareosols

come in the form of solid particles and liquid droplets depending on evaporation times.


26

Classifications of particles as they affect the respiratory system are defined as

inhalable, repairable, and ultrafine.

INOVA Renderings 3,4: Entire Respiratory System (to the Left) and the

Tracheo Bronchial region (to the right) Inhalable particles or particles with approximate diameter (Dp) less than 10um are capable

of depositing any where in the respiratory system. Repairable or fine particles with

approximate diameter (Dp) less than 2.5 um can penetrate gas exchange region of respiratory

system (Alveoli Sacs) and are more likely to be retained than larger inhalable particles. These

particles can pose greater threat to immune system. Ultrafine particles or particles with

approximate diameter (Dp) less than 0.02um are not well characterized and include such

substances as diesel exhaust and or a variety of indoor sources.

The major parts of the respiratory system include: Nasopharyngeal region or regions

including Nostrils to Larynx (throat); Tracheo bronchial region or regions including Trachea

(windpipe), bronchi, Bronchioles; and Pulmonary region or regions including the Lungs and

Alveoli. The normal adult breathing rate through the nose at seated rest condition is

approximately 12 breaths/min and the overall volumetric flow rate at this condition is

approximately 6L/min. The mouth dominates breathing at 34.5 L/min.

The respiratory system is one of the main points of entry for particle size

contaminants. Clearance mechanisms or respiratory protection mechanisms against

contaminates include: removal to digestive tract by cilia in Tracheo bronchia region;

phagocytosis or digestion by macrophages in the lungs; coughing is the rapid expulsion of air


27

from lungs; and sneezing, which is the rapid expulsion of air from nasal passages.

Susceptibility of respiratory system to air contaminates depends on size local air conditions

and velocity. As a result contaminate particles deposit non-uniformly through respiratory

system. Displayed in Appendix A.11 is a chart that shows the break down of respiratory

infections colds (Upper Respiratory Infections). Colds make up the largest single respiratory

infection, influenza will predominate colds during the flu season.

3.8 Air Quality Indicators

Recently indoor air quality (IAQ) has become an important issue and as a result

researchers have developed a number of different air quality indicators. Air quality Indicators

are represented values determined by the space and associated characteristics to show the

quality of air within that space. Two air quality indicators will be used for the purpose of this

study, normalized age of air (inverse to air exchange efficiency) and the contaminate removal

effectiveness.

Equation (4):

Tn = (T)/(Te)

Tn = Normalized age of air (Is the normalized age of air at point in the space.) T = Age of local air (Is the age of air at a point in the space.) Te = Age of air at exhaust (Is the shortest possible time needed for replacing the air in the room.)

Tn > 1 Represents less than ideal age of air. Tn = 1 Represents ideal age of air. Tn < 1 Represents better than ideal age of air

Equation (5): Te = 1 / (ACH) ACH = the number of air changes per hour in a room Equation (6): T = (Tn)/ (ACH) Equation (7): ε = (Ce – Cs ) / (Ca – Cs) ε = Contaminate Removal Effectiveness Ce = Concentration at the exhaust Cs = Concentration supplied to room


28

Ca = Concentration average in room

In the proposed steady the purpose of analyzing space concentration from contaminate by people nothing will be supplied into the space it is assumed that all contaminates introduced by the space leave space through exhausts. Therefore Contaminate Removal Effectiveness will be applied to specific points in space for analyzation of problematic regions: Equation (8): ε = (Ce) / (C) C = Concentration at a point in the room

ε > 1 Represents better than ideal conditions for contaminate removal conditions at a specific point.

ε = 1 Represents ideal contaminate removal conditions or perfect mixing at specific point. ε < 1 represents less than ideal contaminate removal condition at a

specific point Equation (9):

Ce = Σ (Md* Cd)/Σ (Md)

Md = Mass flowexhaust Cd = Concentrationexhaust

To obtain perceived indoor air quality indicators computational fluid dynamics CFD

will be used to calculate distributions of contaminate concentration and local age of air for

the four spaces proposed. The contaminant concentration distributions will be simulated for

secondary contaminants introduced into the space by occupants.

To do this several assumptions were introduced to obtain age of air and concentration

distributions. First, all results were obtained for steady state airflows, which is the case for

spaces where cooling /heating loads do not change rapidly. Influence of infiltration was

neglected, under assumption that the flow rate of the supplied fresh air through the inlets is

much larger than the flow rated cause by infiltration. This assumption of negligible

infiltration implies that there was no contamination inflow or out flow from adjacent spaces.

The final assumption is that contaminant distributions are not influence by different densities

of contaminants and no additional contaminates were introduced into the system through the

supply air terminals.


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3.9 Introducing spaces

A total of 4 multi-occupied spaces were simulated in Pheonic’s computational fluid

dynamic CFD program. Three of the spaces represent actual spaces in the INOVA Heart

Institute. These spaces are: the Ground Floor Transplant Waiting Room; the First Floor

Family Waiting Room; and the Second Floor Post Anesthesia Recovery Room. The fourth

space was simulation validating case, which was located at Centre County Community

Hospital and it was a Surgical Waiting Room.

INOVA Rendering 5: Simulated Spaces

INOVA Rendering 6: Simulated Spaces

First Floor Family Waiting

Second Floor Post Anesthesia Recovery Unit (PACU)

Ground Floor Transplant Waiting Room

CCC Hospital Surgical Waiting Room

Reflected Ceiling Plan Floor/Furniture Plan


30

3.10 Simulation Conditions In the following section is a rendering of a typical seen for each of the following

spaces originally created in 3D AutoCAD and then imported and simulated in Pheonic’s

CFD program. To follow each rendering is a list of important stats that were implemented

and observed for each space simulated. The point of the simulation was to achieve the

design thermal ambient conditions within the space.

Represented simulated values represent a snapshot in time at steady state condition

without transients, which may interrupt flow patterns. Steady state conditions mean flow

patterns have achieved their ultimate state (i.e. temperature, pressure, contamination, and age

of air) without transient interruption, such as movement by people. The reason for this is

because it is difficult to represent the unpredictability nature of people sitting and moving in

and out. This steady state assumption is applicable where people have tendency to be

stationary for duration of time (i.e. just sitting and waiting). The most likely areas for these

assumptions are away from doors and near corners.

The air quality in the occupant’s vicinity is the focus of ventilation design and

therefore, it is important to evaluate air quality in the occupied zone, which depends on the

ventilation strategy, contaminant source and room size.

In general it has been shown that displacement ventilation systems have overall better

performance in eliminating contaminates but are not the best in maintaining of uniform

thermal comfort overall or mixing of spaces and was not strategy simulated. The purpose of

this study is to maintain similar thermal condition while achieving better mixing of the space.

A dilution system with high ACH rate is what was originally designed for the spaces

analyzed. When it comes to temperature and humidity concerns the existing design strategies

that were implemented in these spaces were only modified in the way in which air was

discharged through the supply terminals or the relative location slightly modified.

For feasibility of cost and implementation this study will for the most part maintain

existing conditions and provide low impact solutions to minimize additional cost and

renovation.


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3.10.1 Simulation Conditions “Family Waiting Room”

INOVA Table and Rendering 9,7: Simulated Spaces Conditions

Space: Family Waiting Room

Room Numbers: 01PC29, 01PC28, 01PC27 Floor: 1 Simulated Cell Dimesions: Occupancy: 37 X Plain: 74 Floor Area (ft^2): 1296.73 Y Plain: 115 Volume (ft^3): 11672.2 Z Plain: 22 Volume of air (ft^3): 7669.3 Total: 187,220 Design SA TdB (F): 55 Simulated: Delta T (F) 14.36 Design RA TdB (F): 85 Simulated SA TdB (F) 62.4 Design Delta T (F): 30 Simulated RA TdB (F) 76.76 Design Ambient TdB (F): 72 Simulated Ambient TdB (F): 72 Simulation Iterations: 5000 Design CFM: 1200 Simulation Run Time (hours): 5 Design OA CFM: 360 Simulations Ran: 18 Req. OA CFM (Std. 62) 262.8 Simulated Loads: Air Changes Per Hour 9.4 People (Watts): 3700 Req. Air Changes Per Hour (Hospital): 6 Monitors (Watts): 80 Air Changes Per Hour OA: 2.8 Lights (Watts): 676 *Req. Air Changes Per Hour OA (Hospital): 2 Vending (Watts): 260 Floor Flux (Watts): 733.6 Total Design Load (Watts): 11384.40 Simulated Total Load (Watts): 5449.6 Total Design Load (BTUH): 38880 Simulated Total Load (BTUH): 18611.47


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3.10.2 Simulation Conditions “Post Anesthesia Care Unit”

Space: Post Anesthesia Care Unit Room

Room Numbers: 02PD05,02PD06,02PD07,02PD10,02PD05 (A,B,C,D)Floor: 2 Simulated Cell Dimensions: Occupancy: 17 X Plain: 100 Floor Area (ft^2): 2043.04 Y Plain: 83 Volume (ft^3): 18387.7 Z Plain: 24 Volume of air (ft^3): 10320.7 Total: 199,200 Design SA TdB (F): 55 Simulated: Delta T (F) 10.93 Design RA TdB (F): 85 Simulated SA TdB (F) 66.2 Design Delta T (F): 30 Simulated RA TdB (F) 77.10 Design Ambient TdB (F): 72 Simulated Ambient TdB (F): 72 Simulation Iterations: 5000 Design CFM: 1585 Simulation Run Time (hours): 6 Design OA CFM: 475.5 Simulations Ran: 21 Req. OA CFM (Std. 62) 207.6 Simulated Loads: Air Changes Per Hour 9.2 People (Watts): 1700 Req. Air Changes Per Hour (Hospital): 6 Monitors (Watts): 490 Air Changes Per Hour OA: 2.76 Lights (Watts): 2288 *Req. Air Changes Per Hour OA (Hospital): 2 Floor Flux (Watts): 1000 Total Design Load (Watts): 15036.89 Simulated Total Load (Watts): 5478 Total Design Load (BTUH): 51354 Simulated Total Load (BTUH): 18708.466



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3.10.3 Simulation Conditions “Transplant Waiting Room”

Space: Transplant Waiting Room

Room Numbers: 00PB03,00PB05,00PB06 Floor: G Simulated Cell Dimensions: Occupancy: 52 X Plain: 111 Floor Area (ft^2): 1728.00 Y Plain: 72 Volume (ft^3): 16378.94 Z Plain: 20 Volume of air (ft^3): 11160.85 Total: 159,840 Design SA TdB (F): 55 Simulated: Delta T (F) 9.2 Design RA TdB (F): 85 Simulated SA TdB (F) 67.3 Design Delta T (F): 30 Simulated RA TdB (F) 77 Design Ambient TdB (F): 72 Simulated Ambient TdB (F): 72 Simulation Iterations: 5000 Design CFM: 3060 Simulation Run Time (hours): 6 Design OA CFM: 918 Simulations Ran: 25 Req. OA CFM (Std. 62) 363.7 Simulated Loads: Air Changes Per Hour 16.45 People (Watts): 4900 Req. Air Changes Per Hour (Hospital): 12 Monitors (Watts): 320 Air Changes Per Hour OA: 4.935 Lights (Watts): 2350 *Req. Air Changes Per Hour OA (Hospital): 2 Floor Flux (Watts): 1078 Kids (Watts): 225 Total Design Load (Watts): 29030.22 Simulated Total Load (Watts): 8873 Total Design Load (BTUH): 99144 Simulated Total Load (BTUH): 30303.07



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3.10.4 Simulation Conditions Validating Case: “CCC Hospital’s Surgical Waiting Room”

Space: CCC Hospital (Surgical Waiting Room)

Room Numbers: Surgical Wait

Date Surveyed: 3/10/2004 Floor: G Simulated Cell Dimensions: Occupancy: 22 X Plain: 86 Floor Area (ft^2): 294.85 Y Plain: 53 Volume (ft^3): 808.8433 Z Plain: 22 Volume of air (ft^3): 773.5377 Total: 100,276 Assumed Design SA TdB (F): 55 Simulated: Delta T (F) 13.2 Assumed Design RA TdB (F): 85 Simulated SA TdB (F) 62.6 Assumed Design Delta T (F): 30 Simulated RA TdB (F) 76 Design Ambient TdB (F): 75 Simulated Ambient TdB (F): 75 Design CFM: 698.1 Simulation Iterations: 5000 Design OA CFM: 210 Simulation Run Time (hours): 3 Req. OA CFM (Std. 62) 127.69 Simulations Ran: 16 Air Changes Per Hour 54.3 Simulated Loads: Req. Air Changes Per Hour (Hospital): 6 People (Watts): 2200 Air Changes Per Hour OA: 16.3 Lights (Watts): 620 *Req. Air Changes Per Hour OA (Hospital): 2 Floor Flux (Watts): 100 Total Design Load (Watts): 6622.87 Simulated Total Load (Watts): 2920 Total Design Load (BTUH): 22618.44 Simulated Total Load (BTUH): 9972.384



35

CFD simulations were based on a constant flow and generation rates and performed

at steady state conditions. Accuracy of results will very greatly if performed at, non-steady

state, transient conditions. As a result many more simulations are necessary to provide more

accurate/real life solutions. Accuracy of results in the simulation are a function of size of

mesh created or the number of cells at which temperature, velocity, pressure, contamination,

and age of air are calculated over in a room. For simplicity walls and objects provided zero

diffusion or adsorption of contaminates (i.e. loss rate at which contaminate is re-emitted by

objects).

3.11 Normalized Age of Air Simulation Age of air is the time a particle of air travels from inlet to the point of interest and it is

a function of velocity and the path length followed. Normalized age of air is the age of air at

the point of interest divided by the time a particle travels from inlet to exhaust. If normalized

age of air in any region is greater than (1.0) then the point is less than perfectly well mixed

and stagnant regions can be visibly seen. Simulations were performed to compare the local

relative age of air at any point in the space with the ideal age of air, which is at the exhaust,

or return air. In general if flow increases along a path then stagnant regions or pockets will

decrease and the age of air goes will go down (flow velocities will increase in these areas).

For the purpose of these results normalized age of air will be considered only in the

horizontal breathing plane at a height of 1.3 meters or 4.26 feet unless other wised noted.

See Appendix A.11 for a reference diagram of the normal breathing plane.


36

3.11.1 Normalized Age of Air Simulation “Family Waiting Room”

INOVA Rendering 11: Simulation of Normalized Age of Air & Scale

Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at seated level or 1.3 m Color representation indicates that from a range of 1 to 1.5 that potential stagnant pockets occur in 3 areas within the space. Space without representative color contours represent normalized age of air better than perfect mixing ( < or = 1) or area of no concern.


37

3.11.2a Normalized Age of Air Simulation “Post Anesthesia Care Unit”


Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at seated level or 1.3 m Color representation indicates that from a range of 1 to 1.5 that potential stagnant pockets occur in 3 areas within the space. Space without representative color contours next to dark blue contours represent normalized age of air better than perfect mixing ( < or = 1) or area of no concern.


38

3.11.2b Normalized Age of Air Simulation “Post Anesthesia Care Unit”


Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at patient level or 1.1 m Color representation indicates that from a range of 1 to 1.5 that potential stagnant pockets occur in 1 area within the space. Space without representative color contours next to dark blue contours represent normalized age of air better than perfect mixing ( < or = 1)or area of no concern.


39

3.11.3 Normalized Age of Air Simulation “Transplant Waiting Room”


Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at seated level or 1.3 m Color representation indicates that from a range of 1 to 2 that potential stagnant pockets occur in 2 areas within the space. Space without representative color contours next to dark blue contours represent normalized age of air better than perfect mixing ( < or = 1)or area of no concern. Space without representative color contours next to bright red contours represent normalized age of air worse than perfect mixing ( > or = 2)or area of concern.


40

3.11.4 Normalized Age of Air Simulation, Validating Case: “CCC Hospital’s Surgical Waiting Room”


Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at seated level or 1.3 m Color representation indicates that from a range of 1 to 1.5 that potential regions of concern occur in 3 areas within the space Space without representative color contours next to dark blue contours represent normalized age of air better than perfect mixing ( < or = 1)or area of no concern.


41

3.11.5 Normalized Age of Air Simulation, Regions of Most Concern

In the previous section simulated snap shots were provided for each of the four spaces

simulated at indicated breathing planes. Areas that were boxed out (red or green) were

considered areas of concern based on the normalized age of air. When determining the

regions of most concern for the normalized age of air analysis five points were considered:

quantity and location of people, location of breathing plane, location of entrances and exits,

overall function of space, and critical variations of the age of air within a space. If an area

within a space happens to have a dense population, away from major points of entrances and

exits, in a type of space where people may be situated for a duration of time, where

normalized age of air values exceed ideal values by a considerable percentage it was

considered a region of most concern of which a redesign may be required.

For the spaces excluding the validating case (Family Waiting and Post Anesthesia

Care Unit) the area’s of concern do not meet all the criteria for regions of most concern

established in this section for normalized age of air.

For the space which is the validating case (CCC Hospital, Surgical Waiting Room)

there is evidence that there are region of most concern based on the criteria established in this

section, but because it is not apart of the building which is the focus of this thesis and it will

not be closely looked at or considered for air distribution redesign

For the space, which is, the Transplant Waiting Room there is evidence that there are

regions of most concern based on the criteria established in this section and will be further

investigated closely looked at and considered for an air distribution redesign.

3.11.6 Normalized Age of Air Simulation, Closer look at Transplant Waiting

Room As shown in section 2.10.3 for the Transplant Waiting Room there are (2) areas of

concern that exist when performing the Normalized age of air simulations. After all

simulation were performed, through further investigation and verification with a contact from

the general contractors office it was determined that the area of concern boxed in green did

have an air supply not previously seen in the design documents. Subsequently, for the

purpose of the results previously simulated, it will be assumed that the normalized age of air

in this region is not an issue and will not be considered for redesign.

Closely looking at the remaining region it can be seen that the normalized age of air is

fairly diverse and is for the majority of the region greater than (1.0). This again means that


42

the region is not well mixed and stagnant area’s or pockets can visibly be seen. This may

pose an issue when contaminates are introduced by occupants situated in this region.

Contamination simulations will be done to prove the validity of this assumption.

INOVA Rendering 16: Simulation of Normalized Age of Air


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3.12 Contaminate Removal Effectiveness, 100% Contamination Simulation

Contaminate Removal Effectiveness (CRE) is a ratio of the average exhausted

contaminates to the average number contaminates within the space. If the number of

contaminates in any region is greater than the average exhausted concentrations then that

region is less than perfectly well mixed and stagnant regions can be visibly seen. Areas

where CRE is less then or equal to (1) will be considered ideal conditions and no need to

modify. Simulations were performed to show the relative concentrations throughout the

breathing plan in order to compare with the average exhausted contaminates. The focus of

this analysis will only target secondary contaminates or contaminants introduced into the

space by its occupants. Therefore, for the purpose of this analysis it will be assumed that

supply air will be free from contaminates, this however is an idealized situation and is never

the case in actuality.

The reason for 100% contamination or contamination of all occupants in space at

capacity is to determine at worst case scenario the most problematic area in the space this

will enable one to address “ Regions of most concern” and alleviate problems or problem

areas as seen fit by the engineer. The rate of release of contaminates by an infected

individual will be 6200 droplet nuclei per hour or an equivalent 2.07 particles/m^3/second.

For the purpose of these results the Contaminate removal effectiveness ratio along with the

contaminate concentration will only be considered in the horizontal breathing plane at a

height of 1.3 meters or 4.26 feet unless other wised noted. See Appendix A.12 for a

reference diagram of the normal breathing plane. See Appendix A.13 for CRE calculations.


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3.12.1 CRE , 100% Contamination “Family Waiting Room”

INOVA Rendering 17: “CRE” & Scale

C(exhaust) = 106 particles/m^3 Concentration range set at 106 to 500 particles/m^3 Scale of concentrations: = 106 represents Contaminate Removal effectiveness of (perfect mixing) > 106 represents less than perfect mixing (formation of stagnant pockets occurs) < 106 represents better then perfect mixing Color representation indicates that from the given range of 106 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in 1 major location of concern. Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 106) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.12.2a CRE , Non-Patient Contamination “Post Anesthesia Care Unit”


C(exhaust) = 22 particles/m^3 Breathing Plan: 1.1 meters (for patient in bed ) Concentration range set at 22 to 500 particles/m^3 Scale of concentrations: = 22 represents Contaminate Removal effectiveness of (perfect mixing) > 22 represents less than perfect mixing (formation of stagnant pockets occurs) < 22 represents better then perfect mixing Color representation indicates that from the given range of 22 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in 1 major location of concern. Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 22) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.12.2b CRE , Patient Contamination “Post Anesthesia Care Unit”


C(exhaust) = 16 particles/m^3 Breathing Plan: 1.3 meters (for seated occupants) Concentration range set at 16 to 500 particles/m^3 Scale of concentrations: = 16 represents Contaminate Removal effectiveness of (perfect mixing) > 16 represents less than perfect mixing (formation of stagnant pockets occurs) < 16 represents better then perfect mixing Color representation indicates that from the given range of 16 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in 1 major location of concern. Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 16) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.12.3 CRE , 100% Contamination “Transplant Waiting Room”


C(exhaust) = 66 particles/m^3 Breathing Plan: 1.3 meters (for people sitting) Concentration range set at 66 to 500 particles/m^3 Scale of concentrations: = 66 represents Contaminate Removal effectiveness of (perfect mixing) > 66 represents less than perfect mixing (formation of stagnant pockets occurs) < 66 represents better then perfect mixing Color representation indicates that from the given range of 66 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in 1 major location of concern. Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 66) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.12.4 CRE, 100% Contamination, Validating Case: “CCC Hospital’s Surgical Waiting Room”


C(exhaust) = 107 particles/m^3 Concentration range set at 107 to 500 particles/m^3 Scale of concentrations: = 107 represents Contaminate Removal effectiveness of (perfect mixing) > 107 represents less than perfect mixing (formation of stagnant pockets occurs) < 107 represents better then perfect mixing Color representation indicates that from the given range of 107 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in 1 possible location of concern. Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 107) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.12.5 CRE, 100% Contamination Simulation, Regions of Most Concern In the previous section simulated snap shots were provided for each of the four spaces

simulated at indicated breathing planes. Area’s that were boxed out (red) were considered

areas of concern based on the Contaminate Removal Effectiveness (CRE). When

determining the regions of most concern for the CRE of the space analysis five points must

be considered: quantity and location of people, location of breathing plane, location of

entrances and exits, overall function of space, and critical variations of the contaminate

concentration. If an area within had a dense population, away from major points of

entrances and exits, in a type of space where people may be situated for a duration of time,

where concentration values exceed ideal values removed by the exhaust by a considerable

percentage and where considerable concentration appear to engulf more than one person it

will be considered a region of most concern of which a redesign may be required.

By simulating the unlikely event of worst case scenario or a case where 100% of the

occupants is infected stagnant area’s become most evident and easy to see base on the

simulated pictures. In almost all simulations the highest contaminate concentration are

located around the infected individual or place of origin. This suggests that at these steady

state conditions that the highest concentrations will stay centralized around place of origin

and not inhibit others. By studying the presumed person’s breathing plane effects of

contamination from contaminated person next to a uninfected person it can be seen if for a

duration of time in area of low velocity or low flow quantity of air (i.e. stagnant pocket) that

one unhealthy individual may infect another healthy individual.

For the spaces excluding the validating case (Family Waiting and Post Anesthesia

Care Unit) the area’s of concern do not meet all the criteria for regions of most concern

established in this section for contaminate removal effectiveness at 100% contamination.

Simulations only give general idea of contaminate collection where flow patterns are not

varying with time further simulations must be done to prove it.

For the space which is the validating case (CCC Hospital, Surgical Waiting Room)

there is evidence that there is a region of most concern based on the criteria established in

this section, but because it is not apart of the building which is the focus of this thesis it will

not be closely looked at and considered for air distribution redesign


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For the space, which is, the Transplant Waiting Room there is evidence that there are

regions of most concern based on the criteria established in this section and will be further

investigated closely looked at and considered for an air distribution redesign.

3.12.6 CRE, 100% Contamination Simulation, Closer look at Transplant Waiting Room

As shown in section 2.11.3 for the Transplant Waiting Room there is (1) area of

concern that exist when performing the Contaminate Removal Effectiveness simulation.

Closely looking at the region it can be seen that the contaminate concentration is fairly high

engulfing more than just one individual and is for the majority of the region greater than the

effective removal rate at which the return air ducts exhaust concentration levels This again

means that the region is not well mixed and stagnant area’s or pockets are present. This may

pose an issue when contaminates are introduced by occupants situated in this region.

INOVA Rendering 22: “CRE” Close Look

The results in this simulations show that due to improper air distribution that there is

a potential for concentrations to build up in hazardous areas or areas in which uninfected

people are at risk. A more likely verifying simulation must be done to show the affect of

what may actually occur if a single infected individual is to be located in this region. Areas


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outside of the region of most concern have concentrations closer to the exhaust

concentrations as indicated by the dark blue contour (lower limit value of range is set to

equal exhaust concentrations). This suggests that concentration levels are adequate for

optimal removal from the space. Based on simulated alone results in area in which

normalized age of air and contaminate removal effectiveness simulations suggested not well

mixed regions do not necessarily mean that regions are concernable and should be

redesigned. Only through further investigation and simulation can results be truly validated

3.12.7 CRE, 1 Person Contamination Simulation, Closer look at Transplant

Waiting Room


When simulating one infected individual in the region of most concern it can be see

that at the present steady state conditions. A considerable amount of contaminates collects in

front of another person’s face. The probe value indicates that at steady state an approximate

concentration of 120 particles per meter^3 are present in front of healthy individual.

Although this is a potentially considerable microbial concentration the likelihood of steady

state condition to occur in this corner region must be investigated (i.e. the time it takes to

occur). A dose as little as 20 microbes or CFU of influenza can cause infection in 50% or


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more of the population. This concentration could yield a dose able to infect in 20 mins based

on the breathing rate of rested seated breathing rate (7.66L/min).

3.12.8 Determining the Duration of time for Steady State Conditions to Occur

For well-mixed models determining the steady state conditions is fairly simple and is

characterized by the following equation.

Equation (10):

(Ce – Ct)/( Ce – C0) = exp ( - Q/VxT) Where Q = (Surface area of entry) x (Average Velocity of air) Ce = is the steady state exhaust concentration Ct = the uniform concentration throughout the volume C0= is the concentration present at zero time Q = the total supply flow rate into the space V = is the Volume of the room T = the duration of time that steady state condition take to occur

Unfortunately as seen in the previous simulations well mixed conditions are not

present and in reality will never be present for any spaces. Therefore the above equation will

not apply to the entire space. For sake of simplicity a more approximate approach was taken

for determining the duration of time that steady state conditions take to occur. By taking an

approximate differential control volume, using measured values, directly in front of the

healthy individuals face in which contaminates appear to be present a rough estimate on

duration of time can be obtained for a 99% steady state condition of the approximate well

mixed volume Ce = 120 part/ m3 Ct= 120*0.99 = 118.8 part/m3 C0= 0 part/ m3 V = 2.0645E-4 m3 Surface Area of entry = 4.064 m2 Average Velocity of air= 0.08133 m/s

Duration of time at 99.99% Steady State = approximately 4 - 5 seconds These results suggest in the area of the two occupants, that at even semi steady state

conditions, that it would only take a matter of minutes before the healthy person is exposed

to high infecting concentrations less than or equal to the simulated 120 particles per meter ^3.

It must be remembered that the values that are obtained above are only a rough estimate and

are used to show that within such close proximity high concentrations may develop in the

region directly in front of a susceptible healthy individual, given steady state conditions. It


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must be remembered though that this assumes that the sick individual is producing a constant

generation rate of contaminates. The following simulated picture shows the approximate

location of differential control volume along with flow arrows to show path of air in the

horizontal breathing plane.

INOVA Rendering 24: Duration Control Volume

3.13 1st Proposed Solution The first proposed solution will require the relocation of the two existing perimeter

four-way diffusers. The proposed solution would relocate the existing diffuser two feet over

and two feet up from their original position in the ceiling grid. This solution will require

increasing duct length and determining if any other equipment or piping in the upper plenum

space will be affected. Due to the complexity of upper ceiling plenum space, which may

contain piping for steam, medical gases (3 types), reheat, and preheat water for FCU and

CAV/VAV, telecom wiring, and general electric wiring, a constructability study will be

performed to deem that if relocation of diffusers are necessary is feasible. In the following

section, the original location of diffusers are marked in purple.

In the following re-simulated picture with the new diffusers it can be seen that the

overall concentration levels have been reduced drastically in the normal breathing plane and

that high concentration levels have been, for the most part, isolated to the place of origin or

to the infected individual from which they were generated from. The normalized age of air

has been considerably reduced and the previous region of concern has been reduced moved

away from the normal breathing plane to behind the occupants. Boxed in green are the

previous regions of main concern. Boxed in red are the new areas of concern that may result.


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3.13.1 1st Proposed Solution, CRE, 100% Contamination


C(exhaust) = 66 particles/m^3 Breathing Plan: 1.3 meters (for people sitting) Concentration range set at 66 to 500 particles/m^3 Scale of concentrations: = 66 represents a Contaminate Removal effectiveness of (perfect mixing) > 66 represents less than perfect mixing (formation of stagnant pockets occurs) < 66 represents a better then perfect mixing Color representation indicates that from the given range of 66 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in no major areas of concern Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 66) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.13.2 1st Proposed Solution, Normalized Age of Air

INOVA Rendering 26: Normalized Age of Air & Scale

Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at seated level or 1.3 m Color representation indicates that from a range of 1 to 2 that potential stagnant pockets occur in 1 area within the space, behind occupant’s breathing plane. Space without representative color contours next to dark blue contours represent normalized age of air better than perfect mixing ( < or = 1)or area of no concern. Space without representative color contours next to bright red contours represent normalized age of air worse than perfect mixing ( < or = 2)or area of concern.


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3.13.3 1st Proposed Solution, CRE, One person Contamination


In this simulation for one contaminated person the overall concentration levels in

front of the uninfected occupant to the right has decreased drastically by nearly 5 times to

approximately 20 particles per meter^3 as shown by the new probe value. The solution is

therefore expectable in reducing contaminates.

Surprisingly there were no significant increases or decreases in stratification of air

due to this change in the air distributions. This may be an issue if such redesigns are

considered and may be the focus of future studies. Also ambient temperatures in the region

appear to be approximately the same or better (i.e. no increase in temperature) in this high

occupancy region. This was all due to the flow patterns and throw increase by the proposed

solution.

It is important to remember that simulations only give an approximate estimate of

what concentration levels may be achieved given the conditions represented in each

simulation. Simulations done here have a mesh quantity of 150,000 to 200,000 the

approximate mesh size ranges from one inch near inlets and mouths to six inches over the

majority of the space. A contaminate particle size is roughly 1x10-8 to 1x10-6 meters in

diameter. The simulations that were performed had mesh sizes of no more than 200,000

cells, any more usually caused extremely long iteration time or crashed.


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3.14 2nd Proposed Solution The second proposed solution will require somewhat less work to implement as it is

only to replace the existing (2) diffusers with a combination of both two-way and three-way

diffusers.

The proposed solution would require that the diffuser closest to the corner be replaced

with a two diffuser and the diffuser located towards the bottom of the designated region be

replaced with a three way. This solution is very low impact and would require minimal cost

and effort to implement.

In the following re-simulated picture with the new diffusers it can be seen that the

overall concentration levels have again been reduced considerably in the normal breathing

plane and that high concentration levels again have been isolated to the place of origin. The

normalized age of air has been significantly reduced and the previous region of concern has

been reduced and moved away from the normal breathing plane to behind the occupants like

the previous solution. Boxed in green are the previous regions of main concern. Boxed in red

are the new regions of main concern.


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3.14.1 2nd Proposed Solution, CRE, 100% Contamination


C(exhaust) = 66 particles/m^3 Breathing Plan: 1.3 meters (for people sitting) Concentration range set at 66 to 500 particles/m^3 Scale of concentrations: = 66 represents Contaminate Removal effectiveness of (perfect mixing) > 66 represents less than perfect mixing (formation of stagnant pockets occurs) < 66 represents better then perfect mixing Color representation indicates that from the given range of 66 (dark blue) to 500 (bright red) particles/m^3 that potential stagnant pockets occur in no major areas of concern Space without representative color contours next to dark blue contours represents normalized concentrations that are better than perfect mixing (< 66) or regions of no major concern. Space without representative color contours next to bright red contours represents normalized concentrations that are less than perfect mixing (> 500) or areas of major concern. Regions that are primarily greater than a concentration of 500 occur directly in front of infected and are to be expected and may be neglected.


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3.14.2 2nd Proposed Solution, Normalized Age of Air

INOVA Rendering 29: Normalized Age of Air & Scale

Scale: 0 represents 100 percent fresh air (occurs at inlets) < 1 represents better than perfect mixing 1 represents perfect mixing (occurs at outlets) > 1 represents less then perfect mixing (formation of stagnant pockets occurs) Breathing Plan at seated level or 1.3 m Color representation indicates that from a range of 1 to 2 that potential stagnant pockets occur in 1 area within the space. Space without representative color contours next to dark blue contours represent normalized age of air better than perfect mixing ( < or = 1)or area of no concern. Space without representative color contours next to bright red contours represent normalized age of air worse than perfect mixing ( < or = 2)or area of concern.


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3.14.3 2nd Proposed Solution, CRE, One person Contamination


In this simulation for one contaminated person the overall concentration levels in

front of the uninfected occupant to the right has decreased more than the first proposed

solution by nearly 12 times to approximately 10 particles per meter^3 as shown by the new

probe value. The solution is therefore expectable in reducing contaminates. Surprisingly

there were no significant increases or decreases in stratification of air due to this change in

the air distributions. This may be an issue if such redesigns are considered and may be the

focus of future studies. Also ambient temperatures in the region appear to be approximately

the same or better (i.e. no increase in temperature) in this high occupancy region. This was

all due to the flow patterns and throw increase by the proposed solution.

3.15 Proposed Solutions, Cost Estimate

A cost estimate was done to show which solution was better. For nearly Half the

Price you get twice the effectiveness when removing contaminates from the regions of most

concern by selecting proposed solution #2 Cost include installation and contractors overhead

and profit based on costs provided by RS MEANS. Detailed cut sheets where costs were

obtained can be found in Appendix A.14.


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Proposed Solution # 1: Duct work Cost estimate Solution: 1 Length Inc. (Lft): 4

Dimesion of Duct (in): 10 x 8 90 elbow increase (Lft): 3

Perimeter of Duct (in): 36 Weight/Lft (lb/Lft): 9

Type of duct: S.S. 304 Cost/lb ($): 9.3

# ducts: 2 Above Avg Ins. Increase (%): 25

O & P Total Cost with Insulation ($): 1464.75 INOVA Table 13: Proposed Solution 1, Costs

Proposed Solution # 2: Diffuser Cost Estimate

Type : Cost ($): 2 - way, 24 x 24 380 3 - way, 24 x 24 380

O & P Total Cost ($): 760 INOVA Table 14: Proposed Solution 2, Costs

3.16 Summary When evaluating a space, it must be asked will the case ever exist that is potentially

dangerous to others. Hospital environments are not a place to question indoor air quality

especially with people with comprised immune systems. Solutions that were resolved in this

study were only simulated and not tested, therefore may not be best for these situations or

applicable to other situations. It must be understood that individuals are not all susceptible to

the concentration of contaminates in stagnant pockets deemed unsuitable by this study. The

basis of this research, I have preformed is only at worst case scenario and with the placement

of a single infected individual in regions deemed unsuitable.

The focus of this study was contaminates produced by occupants within multi-

occupied regions, in the normal breathing plane, where most inspiring and expiring occurs.

Two proposed solutions were investigated, that significantly reduced contaminates. The

question that still remains is, “What is safe enough?” So little is known about the effects of

pathogenic contaminates. Most microbes do not live long enough in air and peoples’

immune systems are not the same. The most common forms of viral transmission are

through direct contact, extreme close range with the infected person, and touching surfaces in

which contaminates are deposited. Close range contamination is based on flow patterns,

overall contaminate risk, and dose received. Because contaminates can pose such threat in

hospital environments something must be done to alleviate the problems experienced by

occupied spaces. This report tried to achieve solutions which were effective, efficient and at


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minimal cost to the owner. The simulated results show that nothing can be perfectly

achieved, but methods explored can offer so help in alleviating and rectifying problems.

Although solutions explored do not suggest perfect contaminate removal

effectiveness they do provide better flow patterns, which displace and reduce contaminate

from the designated breathing plane. From the solutions it was seen that moving diffusers is

a more costly endeavor than changing diffuser types and if anything is to be done it is my

recommendation that changing diffusers is easier to maintain, fix, operate, and implement. It

is the most appropriate solution for hospitals such as the INOVA Heart Institute, which

already uses a complex combination of dilution ventilation (high air change rate) and

pressurization. Other systems such as displacement ventilation although better for

contaminate removal were not best solution due to stratification issues as well as complexity

of design for such large diverse spaces.

These simulated results can only approximate dose received by individuals. Unlike

the subjects used in the simulations people expel and inhale contaminates at different rates

and times. The amount that it takes to actually infect varies from person to person as well as

the environment which spreading occurs. The simulations can indicate areas of concerned

with in a space and can suggest ways to improve. The manor of expelling contaminates may

be the focus of another study to determine additional related issues such as deposition of

particles along with re-emitting from surfaces. In general the tendency in design is toward the use of performance standards. The

ability to estimate risk is vital in design. Modeling is one option that can provide us with the

ability to estimate such risks.

In the case of the INOVA Heart Institute it is still a hospital and it is my feeling that

such issues discussed should be assess and at minimum the system should provide proper

distributed air and comfortable climate. Also, the comfort in knowing that situations, if ever

occurs, have been taken into account when the designing the air distribution system.


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4.0 Constructability Analysis (Breathe Study)


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4.0 Constructability Analysis (Breathe Study)

4.1 Background To reduce contaminates in regions deemed of most concern. The redesign of air

distribution system is necessary in this region. Effects of previously simulation require

diffusers to be move to new location in ceiling grid approximately a distance of 4 ft from

original location. Associated ductwork will have to be lengthened to accommodate the new

locations.

4.2 Introducing the Space The Transplant Waiting Room will be the focus of this analysis. Approximate

dimesions and volumes can be found in section 2.9.3 of this report. Below is an AutoCad 3D

rendered image of the space. Diffusers to be relocated are circled in purple.

INOVA Rendering 31: Transplant Diffuser Relocation

4.3 Problem The problem with moving diffusers may cause issues with other equipment and

piping located in the upper plenum space. These obstacles may cause a costly relocating and

displacing issue.


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4.4 Plan of Attack As stated previously the purpose of this investigation is to investigate the upper

plenum space above the Transplant Waiting Room in the INOVA Heart Institute. The

following steps will be done as a result to this investigation.

1. Locate location of equipment, piping, ducting, conduit, and structural features

within the upper plenum space using the design documents.

2. Create a 3D coordination section based on original design documents using

AutoCAD.

3. Develope schedule for approximate sequencing of trades for original design.

4. Create a 3D coordination section based on new design documents using

AutoCAD.

5. Determine how schedule of sequencing of trades is impacted and effected for

new design.

4.5 Investigation of Upper Plenum Space Through investigation of the design documents the following appears to be located in

the upper plenum space.

1. Piping a. Primary Heat Supply lines b. Re-Heat Supply lines for Terminal Reheat Units c. Domestic Water lines d. Fire lines

2. Ducts a. Primary Supply Air to Space b. Primary Return Air from Space

3. Conduit a. Electric to recessed lighting b. Electric to various room sensors c. Telecom to PA speakers

4. CAVs a. One Terminal Reheat Unit

5. Fire protection a. Sprinklers for space below

6. Lighting a. Recessed Lighting for space below

To follow is an actual photo of the installation phase of the Mechanical, Electrical,

and Plumbing MEP taken in the summer of 2003.


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INOVA Photo 4: MEP Coordination

4.6 3D Coordination Section Before Redesign The following is a rendering of the Transplant Waiting Space and associated original

design of the upper plenum space. Diffusers to be relocated are circled in purple. CAV is

hidden from view by airside ducting. Rendering only shows major MEP and Structural

concerns.

INOVA Rendering 32: Original Transplant Diffuser Location


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4.7 Schedule, Sequencing of Trades The following is a schedule for the sequencing of trades based on the evaluation of

the design documents.

1. Main electrical wiring in conduit 2. Waterside piping (list types) 3. Mechanical Equipment (CAV)

a. Connections to reheat water b. Connections to electrical and building automation control system

4. Airside Ductwork a. Includes insulation and taping terminal units

5. Fire Sprinklers a. take offs from main fire line to sprinkler

6. Telecommunications a. sound and paging runs

7. Installation of drop ceiling and fixtures a. Recessed lighting installation and electrical connection b. Diffuser installation and connection to airside equipment c. Sprinkler head installation and connection to fire line take-offs

4.8 3D Coordination Section After Redesign The following is a rendering of the Transplant Waiting Space and associated redesign

of the upper plenum space. Relocated diffusers are circled in purple. Rendering only shows

major MEP and Structural concerns.

INOVA Rendering 33: Transplant Diffuser Relocation


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4.9 Impact of Redesign As shown in the investigation and by detailed coordination sections it is assumed that

no major obstructions (MEP or Structural) were incurred when relocating the ductwork. The

redesign could have been implemented in the original design phase or as a later renovation.

4.10 Summary Through investigation it was determined that the minor redesign of the upper plenum

space was feasible. No major obstructions were to be found. The structural aspect of the

upper plenum space is free from concrete beams, which only appear to be above the middle

and opposite ends of the room near mechanical and elevator shafts. Drop panels (4 inches in

depth) exist above perimeter columns outside the space and pose no issue either. No major

penetration was necessary as no full height (floor to floor) walls were present above the

space. This led to no additional changes needed to be made for fire protection concerns.

The overall depth of the plenum space is approximately 4 feet and much clearance is

available in the region of concern.

If the proposed redesign is to be implemented after initial construction verification of

assumptions based off the design documents must be surveyed. Minor issues that may be of

concern only exist when talking about relocating sprinkler heads and associated take-offs

from the main line. As such locations could not be determined by the design documents.

The redesign of ductwork will be required to maintain existing heights and only lengthened

in the horizontal direction. This is to avoid any interference with existing piping or conduit

take-offs.


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5.0 Daylighting Analysis (Breathe Study)


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5.0 Daylighting Analysis (Breathe Study) 5.1 Background

The INOVA Heart Institute contains approximately 150 patient recovery rooms. Of

these 96 are located around the perimeter of the building and contain acess to windows.

Overall the 400,000ft^2 facility contains approximately 22,726 ft^2 of glazing that is

exposed to the outside.

5.2 Introducing the Space Below is a computer rendered image of a typical patient room along with the

associated floor plan. Each room contains one bed and has access to one shared bathroom.

The approximate area of the patient room is 294 ft^2. The exterior wall area is

approximately 84 ft^2 and the window glazing area is approximately 35 ft^2 for each room.

INOVA Rendering 34,35: Typical Perimeter Patient Room and Floor Plan

5.3 Problem/Solution As stated previously the total exterior glazing area is just under 23,000 ft^2. With

such high amounts of glass exposed to the outside an increase in mechanical loads can be

expected due to solar gain during the day as well as associated losses of heat during the night.

The overall impact on the mechanical system results in wasted energy due to building

envelope design especially for a facility that is operating 24 hours a day. The purpose of this

study will be to optimize the effects described above without decreasing recommended

values of natural daylight. This will be done in hopes of reducing the overall load on the


71

mechanical system which will translate to annual energy savings for the owner. The redesign

for the perimeter patient windows may require renovation of the existing curtain wall façade,

which will also be studied.

5.4 Plan of Attack The proposed solution for this study will be to optimize the glazing area of 96 typical

perimeter patient rooms which will reduce mechanical load and meet recommend natural

daylight illuminances for each space. The following steps will be performed as a result to

this investigation.

1. Determine optimal glazing area based on room characteristics and location of

Facility.

2. Simulate typical patient room to see if recommended natural daylight values

are met.

3. Determine building load and energy usage and estimated HVAC operating

cost.

4. Determine impacts of exterior curtain wall façade.

5. Provide cost analysis of redesign 6. Determine feasibility of implementing redesign.

5.5 Determination of Optimal glazing Much Research was done to determine glazing area that reduces loads while

maintains optimal area for daylight transmission into the space. In a study performed by the

National Renewable Energies Laboratory (NREL) on passive solar architecture the

recommended area of a passive solar feature such as azimuth facing windows is

approximately 10% of the floor area for the region of the country nearest to Washington DC.

This figure is suppose to account for the reduction solar gains in cooling months (March to

September) and increase solar gains in heating months (October to February).

The area of typical patient room is approximately 21’ x 14’ or 294 ft^2. The suggested

window glazing area is approximately 29 ft^2 for the patient room The idea of “ Effective Aperture” for estimates of the optimum glazing area was next

used. Effective Aperture is a relationship that is dependent upon both aperture (window

area) size and visible transmittance as an effective determinant to measure illumination

levels. When the effective aperture, the product of the window to wall ratio and the visible

transmittance of the glazing, is approximately 0.18, daylighting saturation will be achieved.


72

Additional glazing area or light will be counterproductive because it will increase the cooling

loads more than it will reduce the lighting loads. In maximizing daylight benefits and

minimizing mechanical operating cost the following equation was obtained and used to

determine optimal window to wall ratio for window area in the typical patient rooms.

Equation (11):

EA = wwr * vt = 0.18

(vt) = visible transmittance (wwr) = window to wall ratio (EA) = effective aperture

The visible transmittance of the glazing is 55% (Given by Manufacturer, Appendix

B.1). This means that the optimal window to wall area is 0.323 or 32%. The current window

to wall area for a patient room is (35ft^2)/(84ft^2) or 42%. Multiplying this result by the

visible transmittance of 55% gives and effective aperture of 0.23, which is greater than the

recommended value of 0.18 and can be reduced. If the window to wall ratio is reduced to the

recommended value of 32% producing and effective aperture of 0.18 then the area of the

window would be 28ft^2. This attribute can be useful in evaluating the cost effectiveness and the daylighting

potential of a schematic building configuration. The location and height of the window will

determine the distribution of the light admitted as well as the depth and penetration. One rule

of thumb states that the depth of daylight penetration should be about 2.5 times the distance

between the top of a window and the windowsill or approximately ¾ the depth of the room.

5.6 Daylight Simulations From the results in the previous section, the new window area will be simulated into

AGI to see if the minimum recommended daylight factor is met for all perimeter /exterior

facing patient rooms. The window area that will be used for each patient room will be

approximately 28 ft^2 dimensions: 4’-8” x 6’-2 ¼”.

5.6.1 Daylight Simulations, Daylight Factor

The daylight factor at a point in an interior is the ratio of the illuminance produced at

that point by daylight (excluding sunlight) from a sky of known or assumed luminance

distribution to the illuminance on a horizontal plane due to an unobstructed hemisphere of

this sky. No actual information provided that indicates required daylighting for hospitals

environment (i.e. patient room). At the recommendation from the lighting advisor patient


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rooms will liken to bedrooms of house. From the INESA Handbook the a chart

recommending daylight factors and sunlight exposures for a bedroom states: “A minimum

0.5% daylight factor should cover at least 5.6 square meters with the penetration of this zone

being not less than ¾ of the depth of the room facing the window.” In Appendix B.2 the

layout of a typical patient room is shown along with the recommended values indicated

above.

In a conducted study shown in Daylighting Performance and Design about, “25% of

window wall area was the minimum acceptable window size for 50% of the observers but

this had to be increased to about 32 % if 85 % of the people were to be satisfied.” In general

the study recommended that window sizes should be somewhere between 20% and 40% of

the window wall area. If below 20% dissatisfaction will arise. If above a 40% level

satisfaction with window area will be high but unless special measures are taken, such as a

solar control glass, the incidence of thermal and visual discomfort is likely to increase.

5.6.2 Daylight Simulations, AGI The purpose of simulating daylight exposure to each room is to determine if the

minimum 0.5% daylight factor is met in all of the 96 perimeter patient rooms. The following

table illustrates the internal and external reflectance and transmittance values used to perform

such simulations.

Room Type: Perimeter Patient Height above ground (ft): 20

Simulated Room Criteria Feature Reflectance (%): Transmittance

Wall: 0.6 - Floor: 0.3 - Ceiling: 0.8 - Furniture: 0.5 - Window: 0.3 0.55

Ground (outside ) : 0.23 -

INOVA Table 15: Space Design Characteristics

The simulated rendering shown below illustrates South East isometric view of (4)

patient rooms used to perform the simulations. The rooms will be facing: North, South, East,

and West at an elevation of 20 feet (First floor height).


74

INOVA Rendering 36: Typical Perimeter Patient Room

This rendering shows the simulation, which was performed on June 21st or the

Summer Solstice (Longest day of the year) at noon. The simulations will also be performed

on December 21st or Winter Solstice (Shortest day of the year) and on March 21st or Vernal

Equinox (Middle day of the year) also at noontime. For the purpose of this daylight analysis

only illuminance levels will be considered at the peak point in the day or noon. The

simulated values obtained for external illuminace and the associated internal illuminace

needed to meet the minimum daylight factor or shown in the table below. Simulations were

also performed at 8am and 4pm and results can be found in Appendix B.3. Location: Washington D.C. Conditions: Overcast Recommended Daylight Factor (%): 0.5

Time Performed: 12pm External Illumance (fc): Internal Illuminance needed (fc): March 21st

(*Vernal equinox) 6719 33.595June 21st

(Summer solstice) 8920 44.6December 21st

(Winter solstice) 3133 15.665

*Autumnal equinox will produce the same results as the Vernal equinox and will not be simulated.INOVA Table 16: Internal and External Illuminaces


75

These are a sample of simulated daylight views rendered in AGI for the typical patient room on June 21st at noon. INOVA Rendering 37: East view (Noon, June 21) INOVA Rendering 38: West view (Noon, June 21) INOVA Rendering 39: South view (Noon, June 21) INOVA Rendering 40: North view (Noon, June 21)


76

These are illuminace daylight calculations experienced by the room which were performed in AGI for the typical patient room during 3 times of the year at noon. The green contour represents where the minimum internal illuminace values needed no longer meet the recommended values. The window location is locate on the left side of the layout. INOVA AGI Calcs. 1: East View (Noon, June. 21) INOVA AGI Calcs. 2: West View (Noon, June. 21) INOVA AGI Calcs. 3: South View (Noon, June. 21) INOVA AGI Calcs. 4: North View (Noon, June. 21)


77

These are illuminace daylight calculations experienced by the room which were performed in AGI for the typical patient room during 3 times of the year at noon. The green contour represents where the minimum internal illuminace values needed no longer meet the recommended values. The window location is locate on the left side of the layout. INOVA AGI Calcs. 5: East view (Noon, Dec. 21) INOVA AGI Calcs. 6: West View (Noon, Dec. 21) The representative contour for south view is not present because the entire space meets the minimum requirements for daylight. INOVA AGI Calcs. 7: South View (Noon, Dec. 21) INOVA AGI Calcs. 8: North View (Noon, Dec. 21)


78

These are illuminace daylight calculations experienced by the room which were performed in AGI for the typical patient room during 3 times of the year at noon. The green contour represents where the minimum internal illuminace values needed no longer meet the recommended values. The window location is locate on the left side of the layout. INOVA AGI Calcs. 9: East view (Noon, Mar. 21) INOVA AGI Calcs. 10: West View (Noon, Mar. 21) The representative contour for south view is not present because the entire space meets the minimum requirements for daylight. INOVA AGI Calcs. 11: South View (Noon, Mar. 21) INOVA AGI Calcs. 12: North View (Noon, Mar. 21)


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From the daylight simulation analysis it can be seen that minimum daylight factor

requirements are met determined in section 4.6.1 of this study and that the window

reduction is possible.

5.7 Building Loads and Operating Cost From the table shown below the windows that will be involved in the redesign

equate to approximately 15% of the the total glazing of the building. The total reduction

in actual window area (594ft^2) will be approximately 3%.

Window investigated: Direction Quantity West: 39 East: 15 North: 18 South: 24 Total windows: 96 Total window area (ft^2): 3360 Total Building window area (ft^2): 22,726 Percentage of Building (%): 14.78 Reduction in window area (%): 2.7

INOVA Table 17: Windows Investigated To determine the building loads, total energy consumed, operating cost by the

new facility and entire energy analysis was performed in Carrier’s Hourly analysis

program for the entire facility (301,967 ft^2).

Annual Site Energy Consumed after window

reduct Before Window

Reduction after window


Reduction Component (kBTU) (kBTU) (kBTU/ft²) (kBTU/ft²) Air System Fans 21,732,518 21,732,518 71.97 71.97Cooling 12,166,450 12,116,354 40.291 40.125Heating 40,509,900 41,592,020 134.153 137.737Pumps 3,698,295 3,698,203 12.247 12.247Cooling Tower Fans 3,487,921 3,482,731 11.551 11.534

HVAC Sub-Total 81,595,084 82,621,825 270.211 273.612

after window


Reduction after window


Reduction Component (kBTU) (kBTU) (kBTU/ft²) (kBTU/ft²) Cooling Coil Loads 81,472,616 81,077,472 269.806 268.497Heating Coil Loads 33,936,824 34,836,708 112.386 115.366Grand Total 115,409,440 115,914,180 382.191 383.863Conditioned Floor Area (ft²) 301967.7 kBTU/yr Savings with new system implemented: 1,026,741

INOVA Table 18: Annual Energy Consumed


80

From the table shown in the previous page it can be seen that the annual

mechanical load was reduced by approximately a million kBTU/yr. The total mechanical

load before window reduction was estimated at 82.6 million kBTU/yr and after

approximately 81.6 million kBTU/yr. The total reduction is approximately 2% of the

original design. In terms of annual operating cost ($) this translate to approximately

$2400 a year. The total mechanical operating cost before window reduction was

estimated at $430,100 and after approximately $432,500.

Annual Cost Summary To Operate

after window reduct

Before Window Reduction

after window reduct

Before Window

Reduction Component ($) ($) ($)/ft^2 ($)/ft^2 Air System Fans 189,978 190,311 0.629 0.63 Cooling 102,932 102,787 0.341 0.34 Heating 75,207 77,293 0.249 0.256 Pumps 32,329 32,384 0.107 0.107 Cooling Tower Fans 29,671 29,685 0.098 0.098

HVAC Sub-Total 430,116 432,460 1.425 1.432 Conditioned Floor Area (ft²) 301967.7 $/yr Cost Savings with new system implemented 2,344

INOVA Table 19: Annual Energy Consumed

5.8 Impact on Exterior Façade

Below is an elevation of the typical patient room looking at the window

exposed to the outside. Highlighted in red is the approximate window reduction from the

redesign.

INOVA Rendering 41: Interior Patient Room Elevation


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The original dimensions and area of the window are 5’-8” x 6’-2 ¼” and 35 ft^2

Area highlighted in red represents the new window dimensions and area which are 4’-8”

x 6’-2 ¼” and 28ft^2. The change in total area per window per room is 6.2 ft^2. The

total reduction in window area for the 96 rooms is approximately 594 ft^2. Below is an

external view of the elevation for a typical patient room a spandrel glass curtain wall

façade surrounds the patient room window. A typical wall section can be found in

Appendix B.4.

INOVA Rendering 42: Exterior Patient Room Elevation

Structurally the loads for proposed new design do not change relatively much and

will not be analyzed at the suggestion of structural advisor. This is primarily due to the

fact that in the absence of existing window glass, similar curtain wall spandrel glass and

insulation will be replaced along with an extra vertical mullion separating existing

spandrel glass and new spandrel glass to secure the replacement. Replacement spandrel

glass will be used to reduce the cost of replacing a new oversized piece of spandrel glass.

5.9 Cost Analysis The following is a cost analysis on the components that will be changed as a result of

redesigning the window.


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In Appendix B.5 are the associated cost cut sheets provided by RS MEANs.

Window Renovation Cost

Feature $/ft^2 $/unit ft^2 replaced $/room # rooms Total cost

Interior wall: 4.66 - 6.2 28.892 96 2773.632

New window ( 4’-8” x 6’-2 ¼”): - 1735 - 1735 96 166560

Old window ( 5’-8” x 6’-2 ¼” ): - 2107 - 2107 96 202272

Mullion Framing (spandrel Glass): 8.6 - 6.2 53.32 96 5118.72 Painting Interior Walls: 0.84 - 6.2 5.208 96 499.968 Spandrel Glass replacement: 17 - 6.2 105.4 97 10223.8

Curtain wall/Ins. hardware (15% S. Glass): - - - - - 1533.57

Total Cost of Original window: 202272

Total Cost of new window and modifications: 186709.69

Cost Savings from Original Design: 15562.31INOVA Table 20: Window Renovation Cost

The new design would have savings on original design if implemented as the

original design. The annual savings in HVAC Operating cost would be a year $2344

approx. Based on information provided by local consulting firm based out of

Washington DC the typical assumed value for demolition and removal of existing

material such as curtain wall and window facades is approximately 25 % of initial cost.

This means that if the redesign was implemented after original construction that

additional $46,677 would be tacked on to the total cost of the new window and

modifications cost of $186,709 or a total cost of $233,387. This is obviously not a wise

choice if the annual mechanical operating cost savings is only 1% of the new renovation

cost $2344 per year.

5.10 Feasibility of Results. The only way that the new design would be acceptable is if it was initial

implemented as an addendum to the original design before construction. Again, the new

design would have saved approximately $ 15,000 and saved on mechanical operating

costs which was estimated to be $2344 a year. It must be realized that this is all with

respect to loosing 20% of the original window area in the perimeter patient rooms.

Values are only estimated and simulated approximations of cost and may vary.

5.11 Summary The potential for savings through daylighting is affected by location, climate,

building use, and building form. Through the investigation of optimizing of natural


83

daylight it was determined that reducing overall glazing area to achieve mechanical

operating cost benefits was not effective. This is due to the small fraction of actual glass

area that was reduced and the cost of implementation to actually change the windows.

The facility in general is rather large is operational all the time, the cost benefits were

minimal compared to overall mechanical operating cost and sufficient savings were not

realized because of this. It must be noted that the building does have premium quality

glazing with Low-E glass which does perform a valid service when saving energy.


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6.0 Conclusions


85

6.0 Conclusions Integration and coordination of the proposed redesigns required analysis of many

different fields of design. Solutions for redesign were researched, consulted upon,

simulated, assessed and reviewed and not all proposed solutions had positive benefits.

The use of simulation programs gives a good indication of what problems or

benefits a system may encounter. Simulations are only as accurate as the programmer

can make them. They do not in any way perform 100% perfect results or simulate every

aspect or variable in real life situations. Yet simulation such as AGI(Lighting), Carrier’s

Hourly Analysis Program(Mechanical), and Pheonics (CFD) program may and do give,

an indication of what may occur and maybe of value to the engineer before actual

implementation of a system or building. These are an excellent resource in determining

risks and system feasibility, provided that they are correctly used and tested many times.

.


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7.0 Credits and Acknowlegements


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7.0 Credits and Acknowlegements

1. I would like to thank the INOVA Health Care System for letting me use their facility.

2. I would like to thank Turner Construction:

John Almquist Quiton Cooper

3. I would like to thank Centre County Community Hospital: William Stranahan

4. I would like to thank the following MEP engineering consultants: Jim Hoffman Jim Stewart Ann Juran Chris Skoug

5. I would like to thank the Penn State Architectural Engineering Department:

Professor Srebric Professor Friehaut Professor Bahnfleth Professor Mumma Professor Moeck Professor Mistrick

6. I would like to thank the Penn State Architectural Engineering Graduate students:

Atila Novoselac Yazhuo Qian

7. I would like to thank some of the graduating Penn State Architectural Engineering Students (no specific order):

Ben Hagan Jackson Burham Jarod Stanton Joe Firrantello Adam Sontag Sara Lham Lincoln Harberger David Walenga David Clark Katie Trail Mike Carrol Nick Maffeo Craig Dubler Lindy Stowell……


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8.0 References:


89

8.0 References: 1. “Aerobiological Engineering,” http://www.arche.psu.edu/iec/abe/,

March 2004 2. ASHRAE Standard 62-2001, Energy Standards for Buildings. 3. ASHRAE Special Project 1991, “HVAC Design Manual for Hospitals and Clinics,” Atlanta, GA, ASHRAE, 2003. 4. ASHRAE Handbook, “Fundamentals,” ASHRAE, 2001 5. Allen, Edward, “Fundamentals of Building Construction Materials and

Methods,” New York, NY, John Wiley & Sons, 1999.

6. Ander. D Gregg, “Daylighting Performance and Design,” Jon Wiley and Sons, Inc., 2nd Edition, Hoboken, NJ, 2003

7. Balboni, Barbara, “, Assemblies Cost Data,” Kingston, MA, RS MEANS, 28th Edition, 2003.

8. Beggs C.B., “Engineering the Control of AirBorne Pathogens,” http://www.efm.leeds.ac.uk/CIVE/MTB/CBB-paper1.pdf, January 2004 9. Beggs C.B., “The Use of Engineering Measures to Control AirBorne Pathogens in Hospital Buildings,”

http://www.efm.leeds.ac.uk/CIVE/MTB/CBB-Nov8.pdf, March 2004

10. Boyce, P.R., “Human Factors in Lighting,” London, UK, Taylor and Francis Publishing, 2003. 11. Ching, Francis D.K., “Building Construction Illustrated,” New York, NY, John Wiley & Sons, 1991. 12. Dunn, Charles E., Lumalier, “Meeting on UVGI,” Summer Intern, 2003. 13. Heinsohn, Robert., “Indoor Air Quality Engineering,” New York, NY, Marcel Dekker, 1999. 14. Kowalski, Wladyslaw J., “Immune Building Systems Technology,” New York, NY, McGraw Hill, 2003. 15. Kowalski, Wladyslaw J., “Airborne Respiratory Diseases and Mechanical Systems for Control of Microbes,” HPAC, July 2003.

16. Lindeburg, Micheal R., “Engineering Economic Analysis,” Belmont, CA,

Professional Publications, 2001.


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17. Linscomb, Mike., “Aids Clinic HVAC System Limits Spread of TB,”

HPAC, February 1994.

18. Mossman, Melville J., “, Mechanical Cost Data,” Kingston, MA, RS MEANS, 26th Edition, 2003.

19. Novoselac, Atila., “Comparison of Air Exchange Efficiency and Contaminant Removal Effectiveness as IAQ Indices,” ASHRAE, 2003 20. NREL “Renewable Energy; A Guide to the New World of Energy Choices,” http://www.nrel.gov , March 2004 21. Pederson, Curtis O., “Cooling and Heating Load Calculation Principles,” Atlanta, GA, ASHRAE, 1998. 22. Rea, Mark S., “The IESNA Lighting Handbook, Reference and Application,” New York, NY, IESNA Publications Department, 9th Edition, 2000. 23. THERMIE, ”Daylighting in Buildings” http://erg.ucd.ie/mb_daylighting_in_buildings.pdf, November 2003. 23. Turner Construction, Construction Drawings, Shop Drawings and Specifications.

24. Virginia Power,”Schedule GS-3U” http://www.dom.com /customer/pdf/va/vags3u.pdf

26. Washington Gas Light Company, ”Commercial and Industrial Service Schedule No. 2”


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9.0 Appendix:


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9.1 Appendix A.1:

Appendix Table A1: Relative Size of Airborne Pathogens(15)


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9.1 Appendix A.2:

Appendix Table A2: Classifications of Respiratory Pathogens and Sizes(15)


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9.1 Appendix A.3

Appendix Table A3: Classifications of Respiratory Pathogens and Sizes(15)


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9.1 Appendix A.4

Appendix Table A4: Profile of Particle Sizes Produced by an Infectious Person(15)

9.1 Appendix A.5

Appendix Table A5: Communicable Respiratory Infections Characteristic(15)


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9.1 Appendix A.6

Appendix Table A6: Viability of Airborne Microbes Indoors in Absence of Sunlight(15)

9.1 Appendix A.7

Appendix Table A7: Disappearance of airborne sneeze droplets from room air by size(15)


97

9.1 Appendix A.8

Appendix Table A8: Approximate Particle Settling Times(PSU-AE.552)

9.1 Appendix A.9

Appendix Table A9: Routes of Infection of Colds(15)


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9.1 Appendix A.10

Appendix Table A10: Source of Cold Virus Dispersion(15)

9.1 Appendix A.11

Appendix Table A11: Breakdown of Respiratory Infections(15)


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9.1 Appendix A.12




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9.1 Appendix A.13

*Survey Temperature Surface Measurements At Centre County Community Hospital (Used Infrared Temperature Sensor Gun) Simulated CFD Results: Ceiling @ diffuser (Tdb): 62.59 Ceiling @ diffuser (Tdb): 62.59 Back Wall (Tdb): 77 Back Wall (Tdb): 76.038 Front Wall (Tdb): 76 Front Wall (Tdb): 75.2 Left Wall (Tdb): 76.8 Left Wall (Tdb): 76.69 Right Wall (Tdb): 77 Right Wall (Tdb): 76.5 Floor @ Center (Tdb): 76.2 Floor @ Center (Tdb): 74.2

Appendix Table A13a: Validating Surface Temperature Measurements

Appendix Table A13b: Validating Flow Measurements

Appendix Table A13c: Validating Ambient Temperature Measurements

* Measurements performed at the survey done on 3/10/04 along with the CFD simulated results. Variation from measure data and simulated data only vary at most by +/- 2 degrees Fahrenheit. Measured Flows were simulated in CFD.

*Surveyed Flow Measurements: Centre County Community Hospital (Used Flow Funnel over 20 minute period) Average Flow from solo diffuser CFM: 698.4(Notes: Very large flow rate for size of room – very loud)

*Surveyed Ambient Temperature Measurements: Centre County Community Hospital (Used Heat Stress Monitor)

Ambient Temperature (Tdb): 75.4

Ambient Temperature (Twb): 58.1

Ambient Temperature Simulated (Tdb): 75.1(Ambient Temperature taken over 15 minute period)


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9.1 Appendix A.14

Appendix Table A14: Established Breathing Plane(19)

9.1 Appendix A.15

Contaminate Removal Effectiveness (100% infected):

Space: Family Waiting Room

X: 105Y: 104Z: 98.6

Concentration Avg in plans: (C)

Comb. Avg: 102.53

Concentration Avg at Exhaust: RA 1 106

Mass Flow Avg at Exhaust RA 1 0.7286

Total Concentration Avg at exhaust (CE): 106

Contam Remove Effectiveness: (CE/(C) = 1) 1.03

Values represent contaminates introduced by occupants only ( + or – 5% ok)

Appendix Table A15a: Contaminate Removal Effectiveness Simulated Values


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Space: Post Anesthesia Care Unit Room(Patient infected):

(Non-Patient infected):

X: 33.72 12.5 18 Y: 32.75 16.8 22 Z: 29 17.7 25


Comb. Avg: 31.82 15.67 21.67 RA 1 34 6.25 17.5 RA 2 33 20.5 18.2 Concentration Avg at Exhaust: RA 3 32 18.75 32.2 RA 1 0.3254 0.3254 0.3254 RA 2 0.3529 0.3529 0.3529 Mass Flow Avg at Exhaust RA 3 0.2997 0.2997 0.2997

Total Concentration Avg at exhaust (CE): 33.03 15.22 22.26 Contam Remove Effectiveness: (CE/(C) = 1) 1.04 0.97 1.03


Appendix Table A15b: Contaminate Removal Effectiveness Simulated Values

Contaminate Removal Effectiveness (100% infected): Space: Transplant Waiting Room

(1 infected):

X: 58.7 1.5 Y: 62.33 2.2 Z: 77 2.5


Comb. Avg: 66.01 2.07 RA 1 46 1.1 RA 2 74 2.1 Concentration Avg at Exhaust: RA 3 76 3.3 RA 1 0.684 0.684 RA 2 0.5814 0.5814 Mass Flow Avg at Exhaust RA 3 0.627 0.627

Total Concentration Avg at exhaust (CE): 107.40 2.14 Contam Remove Effectiveness: (CE/(C) = 1) 1.02 1.03


Appendix Table A15c: Contaminate Removal Effectiveness Simulated Values


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Space: CCC Hospital

X: 101

Y: 109

Z: 105Concentration Avg in plans: (C)

Comb. Avg: 105

Concentration Avg at Exhaust: RA 1 107.4

Mass Flow Avg at Exhaust RA 1 0.426

Total Concentration Avg at exhaust (CE): 107.4

Contam Remove Effectiveness: (CE/(C) = 1) 1.023


Appendix Table A15d: Contaminate Removal Effectiveness Simulated Values

9.1 Appendix A.16

Appendix Table A16a: RS MEANS Air Supply Duct Fitting Cut Sheets


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Appendix Table A16b: RS MEANS Duct Insulation Cut Sheets

Appendix Table A16c: RS MEANS Air Supply Duct Cut Sheets


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Appendix Table A16d: RS MEANS Air Diffuser Cut Sheets

9.1 Appendix A.17

Diffuser Schedule: 4-way, 2-way, 3-way Throw in Feet (x,y) Throw Direciton and CFM

Type Blow NC 150 fpm 100 fpm 50 fpm X Y TDC-A4 4-way 23 10 12 17 84 84TDC- G2 2-way 23 11 16 22 169 169TDC-A3 3-way 28 11 14 20 127

" " " 10 12 17 84Neck Size (in) 9 x 9 Org. Diffuser: (102/340) Face Size (in) 24 x 24 CFM 340

Appendix Table A17: Titus Diffuser Specifications 9.2 Appendix B.1 :

Type: Low-E Tinted Insulating Glass

Visible Light Transmission

U-Value Winter

U-Value Summer SHGC Shading

Coefficient Outdoor Visible Light Reflectance

55% 0.31 0.34 0.32 0.37 9%

Appendix Table B1: Glazing Attributes

Means Suggest that both 2 way and 3 way cost approx the same.


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9.2 Appendix B.2:

Appendix Table B2: Titus Diffuser Specifications 9.2 Appendix B.3:

Location: Washington D.C. Conditions: Overcast Recommended Daylight Factor (%): 0.5

March 21st (*Vernal equinox) External Illumance (fc):

Internal Illuminance needed (fc):

8am 1910 9.5512pm 6719 33.5954pm 2711 13.555

June 21st (Summer solstice) External Illumance (fc):


8am 4129 20.64512pm 8920 44.64pm 4723 23.615

December 21st (Winter solstice) External Illumance (fc):


8am 459 2.29512pm 3133 15.6654pm 584 2.92

*Autumnal equinox will produce the same results as the Vernal equinox and will not be simulated.

Appendix Table B3: External/Internal Illuminace Values


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9.2 Appendix B.4:

Appendix Table B4: Typical Exterior Wall Section


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9.2 Appendix B.5:

Appendix Table B5a: RS MEANs Dry Wall Cut Sheet

Appendix Table B5b: RS MEANs Typical Window Cut Sheet


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Appendix Table B5c: RS MEANs Mullion Cut Sheet

Appendix Table B5d: RS MEANs Interior Painting Cut Sheet


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Appendix Table B5e: RS MEANs Spandrel glazing Cut Sheet

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