Portfolio - Research and Energy Modeling

A Study of External Wall, Roof, Glazing and Shading Devices

Energy Efficient Design Strategies for Residences in Hot-Dry and Hot Humid Climates

August 4th , 2011 Master of Science in Sustainable Design Sharanya Srinivasan School of Architecture Carnegie Mellon University

This study analyzes the design of energy efficient building envelopes for residences in

hot-dry and hot-humid climates. This study focuses on the effects of exterior wall

insulation, shading, solar absorptances of exterior building components and various

glazing types for air-conditioned buildings in an effort to reduce cooling loads.

Abstract

F l o r i d a Te s t R e s i d e n c e – Wa l l I n s u l a t i o n S t u d y

F l o r i d a S o l a r E n e r g y C e n t e r – Wa l l I n s u l a t i o n S t u d y

Building Enclosure – Reduct ion in Coo l ing Energy

R² = 0.3729

0

10

20

30

40

50

60

0 5 10 15 20 25 30

% R

edu

ctio

n in

Co

olin

g En

ergy

Wall R-value (After) (h-ft2-°F/Btu)

% Reduction in Cooling Energy / Wall R-Value (After) Single and Multi-Family Residences in Hot and Humid Climates

Single Family Residence Multi-Family Residence

Building Enclosure – Reduct ion in Coo l ing Energy

R² = 0.7252

0

10

20

30

40

50

60

0 5 10 15 20 25 30

% R

edu

ctio

n in

Co

olin

g En

ergy


% Reduction in Cooling Energy / Wall R-Value (After) Single Family Residences in Hot and Humid Climates

R² = 0.6203

0

5

10

15

20

25

30

35

40

45

0 5 10 15 20 25 30

% R

edu

ctio

n in

Co

olin

g En

ergy


% Reduction in Cooling Energy / Wall R-Value (After) Single Family Residences in Hot and Dry Climates

Building Enclosure – Cool ing Energy Compar ison

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

HH-MF3 HH-MF5 HH-SF1 HH-SF2 HH-SF3 HH-SF11 HH-SF12 HH-SF13 HH-SF14 HH-SF15 HH-SF16 HH-SF17

An

nu

al C

oo

ling

Ener

gy U

se (

kWh

/m2/y

r)

Cooling Energy Use Comparison (Before and After)

Cooling Energy Before Cooling Energy After

Building Enclosure – Peak Load Reduct ion

R² = 0.5274

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30

% R

edu

ctio

n in

Pea

k C

oo

ling

Load

s


% Reduction in Peak Cooling Loads / Wall R-Values (After) Single and Multi-Family Residences in Hot and Humid Climates

R² = 0.7613

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30

% R

edu

ctio

n in

Pea

k C

oo

ling

Load

s


% Reduction in Peak Cooling Loads / Wall R-Values (After) Single and Multi-Family Residences in Hot and Dry Climates

Building Enclosure – Wal l So la r Absorp tance

0

20

40

60

80

100

HHM1 HHM3 HHM5 HHS12 HHS13 HHS14 HHS15 HHS16 HDS1 HDS2 HDS3

An

nu

al C

oo

ling

Ener

gy U

se (

kWh

/m2/y

r)

Comparison of Annual Cooling Use (Before and After) Wall Solar Absorptances

Cooling Energy (Before) Cooling Energy (After)

Measured Solar absorptances of wall surfaces – Paints

White on Plywood 0.15

White in wood siding 0.25

White Stucco 0.25

Flesh color stucco 0.4

Cream Color 0.41

Light gray aluminium siding 0.45

Light gray color stucco 0.5

Medium gray / blue color 0.65

Tan/Brown color 0.8

Measured Solar absorptances of brick walls

Light colored 0.35 - 0.50

Light red 0.50 - 0.60

Burnt red 0.65 - 0.70

F l o r i d a S o l a r E n e r g y C e n t e r – R o o f R e f l e c t a n c e s t u d y

Building Enclosure – Roof So la r Re f lec tance

R² = 0.2042

0

5

10

15

20

25

30

35

40

45

50

0 0.05 0.1 0.15 0.2 0.25 0.3

% R

edu

ctio

n in

Co

olin

g En

ergy

Roof Solar Absorptance Value

% Reduction in Cooling Energy vs. Roof Absorptance Value

H i g h R i s e H o u s i n g , H o n g K o n g – S h a d i n g S t u d y

Recommendations

Wall Insulation

• The optimum amount and location of thermal insulation is using 5 to 10 cm of insulation located outside or inside. Adding this insulation to the external surface of the uninsulated building envelope prevents heat gain to the interior.

• Comfort conditions are reached faster if insulation is placed along the inside of the external wall.

Recommendations

Wall Solar Absorptance

Reducing the wall solar absorptance from 0.6 (average – medium colored wall) to white wall (0.2) helps reduce the annual cooling energy by 18% and peak cooling load by 23% compared to base case.

Recommendations

Roof Insulation and Reflectance:

Provide a white reflective roofing system with maximum R-19 insulation. This will help reduce the annual cooling energy by an average of 25% compared to dark shingle roof with no insulation.

Performance analysis and HVAC design simulation for TRAILERs

This project is aimed at analyzing and investigating the performance of a trailer for stars with respect to variations in HVAC system type for various configurations and arrangement patterns for the trailers. Two main types of HVAC systems are compared- single duct VAV reheat system and CRV system. OBJECTIVES OF PROJECT: 1. Analyze the performance of the Star Trailer (Pittsburgh, PA) with respect to the HVAC system. 2. Compare the CRV system in the building chosen with the single duct VAV reheat system to analyze which is a better system for the building in terms of a. Satisfying heating demands b. Satisfying cooling demands c. Occupant comfort level in the zones

Introduction

Performance analysis and HVAC design simulation for STAR TRAILERs

Trailer Option 2

Trailer Option 1

Trailer Option 3


Plan , Elevation and Section of the trailer

Floors Gross Area

Stand alone trailer 1 floor

31 m2

Floors Gross Area

Stacked trailer 1st floor 31 m2

2nd floor 31 m2

Floors Gross Area

Side by side trailers

1st floor 62 m2

Climate data

Heating degree days (base 65°) 5968

Cooling degree days (base 65°) 654

Summer design day temp (°C) 31.7

Humidity value 22.5

Month and day of the year 15-Jul

Winter design day temp (°C) -16.8

Humidity value -16.8

Month and day of the year 15-Jan


Step 1: The initial trailer model with its physical parameters like : building geometry, glazing and opening characteristics, construction materials, occupant density, lighting and indoor equipments was developed in design builder V2.0.4.002. Step 2 : The thermal zones were also considered to be constant for the parametric simulation process the detailed HVAC systems were modeled to analyze the performance of the building. Step 3 : The model with required parameters was then exported to energy plus version 4.0.0.024.

Development and analysis of the Trailer in design builder v2.0.4.002:


Development and analysis of the Trailer in design builder v2.0.4.002:

Envelope construction materials

Construction Material Specific heat

(J/kg-k) Density (kg/m3)

R-value U-factor

External Walls FORMAWALL 3" 1503 44.85 21

External Floor Insulated panel 2" (polyisocianurate) 16.27 0.061

Flat roof Bitumen, sheet - thickness 0.01m 1000 1100 Polyisocianurate 4" (0.1016m) 28 0.036

Metal decking 2" (0.0508m)

Complete Roof assembly 28.18 0.035 External doors External door (HM)-

Expanded Polystyrene insulation

15 1400

Windows Windows - Double LowE Clr 3/ 13mm Argon filled, VT .85, SHGC 0.69

2.04


Thermal zones , occupancy schedules & equipments – Option 1 – Single trailer

Zone details Net Area (m2) Occupancy (people/m2)

Lighting (W/m2)

Plug and process* (W/m2)

Under Floor Plenum - Plenum UF Unconditioned 28.7 0 0 0

Module 1 - Mech room South Conditioned 0.68 0 3 0

Module 1 - Mech room North Conditioned 0.86 0 3 0

Module 1 - Bathroom Conditioned 3.68 0.5 9 0

Module 1 - Mod 1_amb 1 Conditioned 23.68 3.1 25 25

Total Area 57.6

System Source Capacity (W) Efficiency

Single Duct Variable Air Volume Reheat

CHILLER Electric 5356.01 1.73

BOILER Gas 16421.76 0.75

VAV System CRV System

System Source Capacity (W) Efficiency

(W/W) Constant volume DX (unitary multi-zone)

AHU Cooling Coil (DX Single speed) Electric 6395.34 3 AHU Heating Coil (Gas) Gas 9433.79 0.8 AHU Supply fan Electric 303.71 0.7


VAV – Block Model


VAV – Nodal Model


CASE 1- single duct VAV (variable air volume) reheat system:

Setpoint and setback temperatures

Heating period (°C)

Heating 22

Heating set back 12

Cooling period (°C)

Cooling 24

Cooling set back 28

05

101520253035404550

During Heating[hr]

During Cooling[hr]

DuringOccupied

Cooling [hr]

Trailer (Facility) -Option 1



Hours of Temperature Set point not met

0

500

1000

1500

2000

2500

3000

WinterClothes [hr]

SummerClothes [hr]

Summer orWinter

Clothes [hr]




Time Not Comfortable Based on Simple ASHRAE 55-2004

0

50

100

150

200

250

300

Option 1 Option 2 Option 3

VAV - kWh/m2

Kwh

Heating

Cooling

Interior lighting

Interior equipment

Fans

Pumps

Total Energy Consumption – By End Use


0.00

5.00

10.00

15.00

20.00

25.00

30.00

Total (kWh/m2)

Monthly Energy Consumption for VAV systems in trailers

Trailer Option 1

0.00

5.00

10.00

15.00

20.00

25.00

30.00

Total (kWh/m2)

Trailer Option 2

0.00

5.00

10.00

15.00

20.00

25.00

Total (kWh/m2)

Trailer Option 3


CASE 2- CONSTANT REHEAT VOLUME SYSTEM- WITH MINIMUM HUMIDITY:

Setpoint and setback temperatures

Heating period (°C)

Heating 22

Heating set back 12

Cooling period (°C)

Cooling 24

Cooling set back 28

0

500

1000

1500

2000

2500

3000

WinterClothes [hr]

SummerClothes [hr]

Summer orWinter

Clothes [hr]




Time Not Comfortable Based on Simple ASHRAE 55-2004

0

500

1000

1500

2000

2500

3000

3500

4000

DuringHeating [hr]

DuringCooling [hr]

DuringOccupied

Heating [hr]

DuringOccupied

Cooling [hr]



Trailer (Facility) - Option3

Hours of Temperature Set point not met By end use Kwh

Heating

Cooling

Interior lighting

Interior equipment

Fans

Pumps

Total Energy Consumption – By End Use

A Strategic Opportunity for the Renovation of

Dormitory at Carnegie Mellon

8 April 2011

48-723 Performance of Advanced Building Systems Prof. Volker Hartkopf

Goals

Reduce Energy Consumption

Improve Thermal Comfort

Improve Air Quality + Occupant Health

Meter, Verify, and Report Actual Performance for Different Decision Makers

Educate Students about consumption habits

Provide Data for Research

Turn an “eyesore” into a gem

Overview Energy Consumption

Health + Comfort

Education + Research

Metering + Commissioning

Campus Appeal

EXISTING FAÇADE

Single Pane window

Blue colored glass – bad quality Daylighting

No insulation

Very poor thermal quality

Poor Indoor air quality

Over heating in summer conditions

Leaky façade

No maintenance

No privacy for occupants


Health + Comfort



Campus Appeal

PROPOSED FAÇADE – option 1

• Heat Loss/Gain Control

• Natural Ventilation

• Privacy and Solar Control

• Daylighting

• Visual Access

• Glare Control


Health + Comfort



Campus Appeal

PROPOSED FAÇADE

Polycarbonate sheet - Allows diffused light

Awning window -Natural ventilation and -Thermo siphoning effect

5” thk. Polyisoboard Insulation – CMU construction

Internal shades for glare control

Illuminance

Proposed Façade Existing Façade

Luminance

Existing façade without shading (June 22) Proposed façade with shading (June 22)

Energy Performance & CO2 Emissions

Energy Performance comparison


Health + Comfort



Campus Appeal

0

20

40

60

80

100

120

140

160

180

200

Existing façade Retrofit façade

Energy Performance

Site energy Source energy

0

10

20

30

40

50

60

70

80

90

100

Existing façade Retrofit façade

Space conditioning demand

Heating demand Cooling demand

kBtu

/ft2

yr

kBtu

/ft2

yr

Site energy 72% Source energy 68%

Percentage reduction

Portfolio - Research and Energy Modeling

Documents

Transcript of Portfolio - Research and Energy Modeling