Ventilation of Health Care Facilities -...

ASHRAE/ASHE STANDARDASHRAE/ASHE STANDARD

ANSI/ASHRAE/ASHE Standard 170-2008

Ventilation ofHealth Care Facilities

Approved by the ASHRAE Standards Committee on June 21, 2008; by the ASHRAE Board of Directors onJune 25, 2008; by the American Society for Healthcare Engineering of the American Hospital Association onJuly 18, 2008; and by the American National Standards Institute on July 24, 2008.

This standard is under continuous maintenance by a Standing Standard Project Committee (SSPC) for whichthe Standards Committee has established a documented program for regular publication of addenda or revi-sions, including procedures for timely, documented, consensus action on requests for change to any part ofthe standard. The change submittal form, instructions, and deadlines may be obtained in electronic form fromthe ASHRAE Web site, http://www.ashrae.org, or in paper form from the Manager of Standards. The latest edi-tion of an ASHRAE Standard may be purchased from ASHRAE Customer Service, 1791 Tullie Circle, NE,Atlanta, GA 30329-2305. E-mail: [email protected]. Fax: 404-321-5478. Telephone: 404-636-8400 (world-wide), or toll free 1-800-527-4723 (for orders in US and Canada).

© Copyright 2008 ASHRAEISSN 1041-2336

American Society of Heating, Refrigeratingand Air-Conditioning Engineers, Inc.

1791 Tullie Circle NE, Atlanta, GA 30329www.ashrae.org

ASHRAE STANDARDS COMMITTEE 2007–2008

Stephen D. Kennedy, ChairHugh F. Crowther, Vice-ChairRobert G. BakerMichael F. BedaDonald L. BrandtSteven T. BushbyPaul W. CabotKenneth W. CooperSamuel D. Cummings, Jr.K. William DeanRobert G. DoerrRoger L. HedrickEli P. Howard, IIIFrank E. Jakob

Nadar R. JayaramanByron W. Jones

Jay A. KohlerJames D. Lutz

Carol E. MarriottR. Michael MartinMerle F. McBride

Frank MyersH. Michael NewmanLawrence J. SchoenBodh R. SubherwalJerry W. White, Jr.

Bjarne W. Olesen, BOD ExOLynn G. Bellenger, CO

Claire B. Ramspeck, Assistant Director of Technology for Standards and Special Projects

SPECIAL NOTE

This American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of the AmericanSociety of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Consensus is defined by the American National StandardsInstitute (ANSI), of which ASHRAE is a member and which has approved this standard as an ANS, as “substantial agreement reached bydirectly and materially affected interest categories. This signifies the concurrence of more than a simple majority, but not necessarily unanimity.Consensus requires that all views and objections be considered, and that an effort be made toward their resolution.” Compliance with thisstandard is voluntary until and unless a legal jurisdiction makes compliance mandatory through legislation.

ASHRAE obtains consensus through participation of its national and international members, associated societies, and public review.ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. The Project

Committee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAE members, allmust be technically qualified in the subject area of the Standard. Every effort is made to balance the concerned interests on all ProjectCommittees.

The Assistant Director of Technology for Standards and Special Projects of ASHRAE should be contacted for:a. interpretation of the contents of this Standard,b. participation in the next review of the Standard,c. offering constructive criticism for improving the Standard, ord. permission to reprint portions of the Standard.

DISCLAIMER

ASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public in light of available information andaccepted industry practices. However, ASHRAE does not guarantee, certify, or assure the safety or performance of any products, components,or systems tested, installed, or operated in accordance with ASHRAE’s Standards or Guidelines or that any tests conducted under itsStandards or Guidelines will be nonhazardous or free from risk.

ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDS

ASHRAE Standards and Guidelines are established to assist industry and the public by offering a uniform method of testing for ratingpurposes, by suggesting safe practices in designing and installing equipment, by providing proper definitions of this equipment, and by providingother information that may serve to guide the industry. The creation of ASHRAE Standards and Guidelines is determined by the need for them,and conformance to them is completely voluntary.

In referring to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, either stated or implied,that the product has been approved by ASHRAE.

ASHRAE Standing Standard Project Committee 170Cognizant TC: TC 9.6, Healthcare Facilities

SPLS Liaison: H. Michael Newman

Richard D. Hermans, Chair* Peter Hogan Langowski*Paul T. Ninomura, Vice-Chair* Anand K. Seth*Michael F. Mamayek, Secretary* Rajendra N. Shah*

Theodore Cohen* Dennis E. ShaughnessyGeorge A. Freeman Michael Patrick Sheerin*Gerald L. Hendrickson Robert J. WeberMichael R. Keen* Michael E. Woolsey*William M. Kingrey Xudong YangMarvin L. Kloostra* Michael Mayo

Frederick H. Kohloss* Denotes members of voting status when the document was approved for publication

CONTENTS

ANSI/ASHRAE/ASHE Standard 170-2008Ventilation of Health Care Facilities

SECTION PAGE

Foreword ................................................................................................................................................................... 2

1 Purpose .......................................................................................................................................................... 2

2 Scope ............................................................................................................................................................. 2

3 Definitions....................................................................................................................................................... 2

4 Compliance..................................................................................................................................................... 3

5 Planning.......................................................................................................................................................... 4

6 Systems and Equipment................................................................................................................................. 4

7 Space Ventilation............................................................................................................................................ 6

8 Planning, Construction, and System Start Up .............................................................................................. 11

9 Normative References.................................................................................................................................. 12

Informative Annex A ......................................................................................................................................... 12

Informative Annex B: Bibliography ................................................................................................................... 13

NOTE

When addenda, interpretations, or errata to this standard have been approved, they can be downloaded free of charge from the ASHRAE Web site at www.ashrae.org.

© Copyright 2008 American Society of Heating,Refrigerating and Air-Conditioning Engineers, Inc.

1791 Tullie Circle NEAtlanta, GA 30329www.ashrae.org

All rights reserved.

2 ANSI/ASHRAE/ASHE Standard 170-2008

(This foreword is not part of this standard. It is merelyinformative and does not contain requirements necessaryfor conformance to the standard. It has not beenprocessed according to the ANSI requirements for astandard and may contain material that has not beensubject to public review or a consensus process.Unresolved objectors on informative material are notoffered the right to appeal at ASHRAE or ANSI.)

FOREWORD

ANSI/ASHRAE/ASHE Standard 170, Ventilation ofHealth Care Facilities, is one of a family of documents thatoffers guidance, regulation, and mandates to designers ofhealth care facilities. It is first and foremost a mandatory min-imum requirement and, as such, may not offer the state-of-the-art best practice of health care ventilation design. Other publi-cations, such as the ASHRAE HVAC Design Manual for Hos-pitals and Clinics, may provide more depth and detail for thedesigner. In addition, the health care designer must refer toany design requirements from the appropriate jurisdiction thathas authority. Many jurisdictions use or refer to Guidelinesfor Design and Construction of Hospitals and Health CareFacilities, published by the American Institute of Architects(AIA). Where practical, the committee was cognizant of theseother documents in the development of this standard.

Ventilation design for health care spaces is a combinationof tasks that leads to a set of documents used in construction.One such task requires medical planners to develop depart-mental programs of spaces. These programs include spacenames that suggest the use for which the space is intended,and health care ventilation designers depend upon thesenames to determine the ventilation parameters for theirdesigns. This standard provides these ventilation parameters.

Without high-quality ventilation in health care facilities,patients, health care workers, and visitors can becomeinfected through normal respiration of particles in the air.Poorly ventilated health care facilities are places where thelikelihood of pathogenic particles occurring in the air is quitehigh. These air-transmitted pathogens can be found every-where in poorly ventilated health care facilities, and althoughmost individuals can cope using their healthy immune sys-tems, some patients are susceptible to these pathogens or evento normal environmental air-borne organisms such as fungalspores. Because these organisms are found in higher concen-trations in hospitals, additional care must be taken in designof the ventilation systems.

1. PURPOSE

The purpose of this standard is to define ventilationsystem design requirements that provide environmentalcontrol for comfort, asepsis, and odor in health care facilities.

2. SCOPE

2.1 The requirements in this standard apply to patient careareas and related support areas within health care facilities,including hospitals, nursing facilities, and outpatient facilities.

2.2 This standard applies to new buildings, additions toexisting buildings, and those alterations to existing buildingsthat are identified within this standard.

2.3 This standard considers chemical, physical, and biolog-ical contaminants that can affect the delivery of medical careto patients; the convalescence of patients; and the safety ofpatients, health care workers, and visitors.

3. DEFINITIONS

addition: an extension or increase in floor area or height of abuilding, building system, or equipment.

airborne infection isolation (AII): the isolation of patientsinfected with organisms spread by airborne droplet nuclei lessthan 5 µm in diameter (see CDC [2003] in Informative Annex B:Bibliography). For the purposes of this standard, the abbreviation“AII” refers to the room that provides isolation.

airborne infection isolation room: a room that is designedaccording to the requirements of this standard and that isintended to provide airborne infection isolation.

alteration: a significant change in the function or size of a space,in the use of its systems, or in the use of its equipment, eitherthrough rearrangement, replacement, or addition. Routine main-tenance and service shall not constitute an alteration.

authority having jurisdiction: the agent or agency responsiblefor enforcing this standard.

average velocity: the volumetric flow rate obtained by divid-ing the air quantity issuing from an air distribution device bythe nominal face area of the device.

building: a structure that is wholly or partially enclosed withinexterior walls and a roof, or within exterior and party walls anda roof, and that affords shelter to persons, animals, or property.In this standard, a building is a structure intended for use as ahospital or health care facility.

classification of surgeries:

Class A surgery: provides minor surgical proceduresperformed under topical, local, or regional anesthesiawithout preoperative sedation. Excluded are intravenous,spinal, and epidural procedures, which are Class B or Csurgeries.

Class B surgery: provides minor or major surgical proce-dures performed in conjunction with oral, parenteral, orintravenous sedation or performed with the patient underanalgesic or dissociative drugs.

Class C surgery: provides major surgical procedures thatrequire general or regional block anesthesia and/orsupport of vital bodily functions.

For more information on this method of classifying surgeries,see ACS (2000) in Informative Annex B: Bibliography.

equipment: devices for heating, ventilating, and/or air condi-tioning, including but not limited to furnaces, boilers, airconditioners, heat pumps, chillers, and heat exchangers.

ANSI/ASHRAE/ASHE Standard 170-2008 3

high risk immunocompromised patients: patients who havethe greatest risk of infection caused by airborne or waterbornemicroorganisms. These patients include but are not limited toallogeneic stem-cell transplant patients and intensive chemo-therapy patients.

infection control risk assessment (ICRA): a determination ofthe potential risk of transmission of various infectious agentsin the facility, a classification of those risks, and a list ofrequired practices for mitigating those risks during construc-tion or renovation.

immunocompromised patients: patients whose immunemechanisms are deficient because of immunologic disorders(e.g., human immunodeficiency virus [HIV] infection orcongenital immune deficiency syndrome), chronic diseases(e.g., diabetes, cancer, emphysema, or cardiac failure), orimmunosuppressive therapy (e.g., radiation, cytotoxic chemo-therapy, anti-rejection medication, or steroids) (see CDC[2003] in Informative Annex B: Bibliography).

inpatient: a patient whose stay at the health care facility is antic-ipated to require twenty-four hours or more of patient care.

invasive imaging procedure room: a room in which radio-graphic imaging is used and in which instruments or devicesare inserted into patients through the skin or body orifice understerile conditions for diagnosis and/or treatment.

non-aspirating diffuser: a diffuser that has unidirectionaldownward airflow from the ceiling with minimum entrain-ment of room air. Classified as ASHRAE Group E, thesediffusers generally have very low average velocity. For thepurposes of this standard, the performance of these diffusers isto be measured in terms of average velocity.

protective environment room: a patient room that is designedaccording to this standard and intended to protect a high riskimmunocompromised patient from human and environmentalairborne pathogens.

triage: the process of determining the severity of the illness ofor injury to patients so that those who have the most emergentillnesses/injuries can be treated immediately and those lessseverely injured can be treated later or in another area.

4. COMPLIANCE

4.1 Compliance Requirements

4.1.1 New Buildings. New buildings shall comply withthe provisions of this standard.

4.1.2 Existing Buildings

4.1.2.1 Additions to Existing Buildings. Additionsshall comply with the provisions of this standard.

4.1.2.2 Alterations to Existing Buildings. Portions ofa heating, ventilating, and air-conditioning system and othersystems and equipment that are being altered shall complywith the applicable requirements of this standard.

4.1.2.2.1 Heating, Ventilation, and Air-ConditioningSystem Alterations. Alterations to mechanical systems servingthe building heating, cooling, or ventilating needs shall comply

with the requirements of Section 6, “Systems and Equipment,”applicable to those specific portions of the building and its sys-tems that are being altered. Any new mechanical equipmentinstalled in conjunction with the alteration as a direct replace-ment of existing mechanical equipment shall comply with theprovisions of Sections 6.2, 6.4, 6.5, and 6.6.

4.1.2.2.2 Space Alterations. Alterations to spaceslisted in Table 6-1 (see page 5) shall comply with the require-ments of Section 6.7 and Section 7, “Space Ventilation,” appli-cable to those specific portions of the building and its systemsthat are being altered. Any alteration to existing health care spacein a building that will continue to treat patients during construc-tion shall comply with Sections 8.1, 8.3, 8.4, and 8.5.

4.2 Administrative Requirements. Administrativerequirements relating to permit requirements, enforcement bythe authority having jurisdiction, interpretations, claims ofexemption, approved calculation methods, rights of approvedcalculation methods, and rights of appeal are specified by theauthority having jurisdiction.

4.3 Compliance Documents

4.3.1 General. Compliance documents are those plans,specifications, engineering calculations, diagrams, reports,and other data that are approved as part of the permit by theauthority having jurisdiction. The compliance documentsshall include all specific construction-related requirements ofthe owner’s infection control risk assessment.

4.3.2 Construction Details. Compliance documents shallcontain all pertinent data and features of the building, equip-ment, and systems in sufficient detail to allow a determinationof compliance by the authority having jurisdiction and to indi-cate compliance with the requirements of this standard.

4.3.3 Supplemental Information. Supplemental infor-mation necessary to verify compliance with this standard,such as calculations, worksheets, compliance forms, vendorliterature, or other data, shall be made available when requiredby the authority having jurisdiction.

4.4 Alternate Materials, Methods of Construction, orDesign. The provisions of this standard are not intended toprevent the use of any material, method of construction,design, or building system not specifically prescribed herein,provided such construction, design, or building system hasbeen approved by the authority having jurisdiction as meetingthe intent of this standard.

4.5 Informative Appendices. The informative appendicesto this standard and informative notes located within this stan-dard contain recommendations, explanations, and other non-mandatory information and are not part of this standard.

4.6 Criteria Ranges. This standard often specifies a rangeof values that will comply with a specific requirement of thestandard. If it is permitted by the authority having jurisdiction,compliance with this requirement may be achieved by the pre-sentation of compliance documents that demonstrate a sys-tem’s ability to perform within the specified range.


5. PLANNING

Owners/managers of health care facilities shall prepare adetailed program that shall include the clinical service expectedin each space, the specific equipment expected to be used ineach space, and any special clinical needs for temperature,humidity, and pressure control. This program shall be preparedin the planning phase of design.

6. SYSTEMS AND EQUIPMENT

Air-handling and distribution systems are required toprovide health care facilities not only with a comfortable envi-ronment but also with ventilation to dilute and remove contam-inants, to provide conditioned air, and to assist in controllingthe transmission of airborne infection. In order to meet theserequirements, air-handling and distribution systems shall bedesigned according to the requirements of this standard.

6.1 Utilities

6.1.1 Ventilation Upon Loss of Electrical Power. Thespace ventilation and pressure relationship requirements ofTable 7-1 (see page 7) shall be maintained for the followingspaces, even in the event of loss of normal electrical power:

a. AII roomsb. PE roomsc. Class B & C Operating Rooms, including Delivery

Rooms (Caesarean)

For further information, see NFPA 99 (2005), in InformativeAnnex B: Bibliography.

6.1.2 Reserve Heating and Cooling Sources

6.1.2.1 Provide heat sources and essential accessoriesin number and arrangement sufficient to accommodate thefacility needs, even when any one of the heat sources is notoperating due to a breakdown or routine maintenance. Thecapacity of the remaining source(s) shall be sufficient to pro-vide for sterilization and dietary purposes and to provide heat-ing for operating, delivery, birthing, labor, recovery,emergency, intensive care, nursery, and inpatient rooms. (Forfurther information, see AIA (2001) in Informative Annex B:Bibliography.

Exception: Reserve capacity is not required if the ASHRAE99% heating dry bulb temperature for the facility isgreater than or equal to 25°F.

6.1.2.2 For central cooling systems greater than 400tons peak cooling load, the number and arrangement of cool-ing sources and essential accessories shall be sufficient to sup-port the owner's facility operation plan upon a breakdown orroutine maintenance of any one of the cooling sources.

Exception: Reserve capacity is not required if theASHRAE 1% cooling dry bulb temperature is less thanor equal to 85°F.

6.2 Air-Handling Unit Design

6.2.1 Air-Handling Unit Casing. The casing of the air-handling unit shall be designed to prevent water intrusion,resist corrosion, and permit access for inspection and mainte-

nance. All airstream surfaces of air-handling units—e.g., inte-rior surfaces and components—shall comply with Section 5.5of ANSI/ASHRAE Standard 62.1-2007, Ventilation forAcceptable Indoor Air Quality. (For more information, seeANSI/ASHRAE Standard 62.1-2007 and ASHRAE positiondocument Minimizing Indoor Mold Problems through Man-agement of Moisture in Building Systems.)

6.3 Outdoor Air Intakes and Exhaust Discharges

6.3.1 Outdoor Air Intakes. Outdoor air intakes for air-handling units shall be located a minimum of 25 ft (8 m) fromcooling towers and all exhaust and vent discharges. Outdoorair intakes shall be located such that the bottom of the airintake is at least six ft (2 m) above grade. Intakes on top ofbuildings shall be located a minimum of three ft (1 m) aboveroof level. New facilities with moderate-to-high risk of naturalor man-made extraordinary incidents shall locate air intakesaway from public access. All intakes shall be designed to pre-vent the entrainment of wind-driven rain, shall contain featuresfor draining away precipitation, and shall be equipped with abirdscreen of mesh no smaller than 0.5 in. (13 mm).

6.3.2 Exhaust Discharges. Exhaust discharge outletsthat discharge air from AII rooms, bronchoscopy rooms,emergency department waiting rooms, nuclear medicine lab-oratories, radiology waiting, and laboratory chemical fumehoods shall

a. be designed so that all ductwork in occupied spaces isunder negative pressure;

b. discharge in a vertical direction at least 10 ft (3 m) aboveroof level and shall be located not less than 10 ft horizon-tally from air intakes, openable windows/doors, or areasthat are normally accessible to the public or maintenancepersonnel and that are higher in elevation than the exhaustdischarge; and

c. be located such that they minimize the recirculation ofexhausted air back into the building.

6.4 Filtration. Filter banks shall be provided in accordancewith Table 6-1. Each filter bank with an efficiency of greaterthan MERV 12 shall be provided with an installed manometeror differential pressure measuring device that is readily acces-sible and provides a reading of differential static pressureacross the filter to indicate when the filter needs to bechanged. (For further information, see AIA [2006] and CDC[2003] in Informative Annex B: Bibliography.)

6.4.1 First Filtration Bank. Filter Bank No. 1 shall beplaced upstream of the heating and cooling coils such that allmixed air is filtered.

6.4.2 Second Filtration Bank. Filter Bank No. 2 shall beinstalled downstream of all wet air cooling coils and the supplyfan. All second filter banks shall have sealing interface surfaces.

6.5 Heating and Cooling Systems

6.5.1 Cooling Coils and Drain Pans. Cooling coils anddrain pans shall comply with the requirements of ANSI/ASHRAE Standard 62.1-2007.


6.5.2 Radiant Cooling Systems. If radiant cooling panelsare utilized, the chilled-water temperature shall alwaysremain above the dew point temperature of the space.

6.5.3 Radiant Heating Systems. If radiant heating is pro-vided for an AII room, a protective environment room, a woundintensive care unit (burn unit), or a room for any class of sur-gery, either flat and smooth radiant ceiling panels with exposedcleanable surfaces or radiant floor heating shall be used.

6.6 Humidifiers. When outdoor humidity and internalmoisture sources are not sufficient to meet the requirementsof Table 7-1, humidification shall be provided by means ofthe health-care facility air-handling systems. Locate humid-ifiers within air-handling units or ductwork to avoid mois-ture accumulation in downstream components, includingfilters and insulation. Chemical additives used for steamhumidifiers serving health care facilities shall comply withFDA requirements.1 Reservoir-type water humidifiers orevaporative-pan-type humidifiers shall not be used in duct-work or air-handling units in health care facilities. A humid-ity sensor shall be provided, located at a suitable distancedownstream from the steam injection source. Controls shallbe provided to limit duct humidity to a maximum value of

90% RH when the humidifier is operating. Humidifier steamcontrol valves shall be designed so that they remain OFF

whenever the air-handling unit is not in operation.

6.7 Air Distribution Systems

6.7.1 General. Maintain the pressure relationshipsrequired in Table 7-1 in all modes of HVAC system operation,except as noted in the table. Spaces listed in Table 7-1 thathave required pressure relationships shall be served by fullyducted returns. The air-distribution design shall maintain therequired space pressure relationships, taking into account rec-ommended maximum filter loading, heating-season loweredairflow operation, and cooling-season higher airflow opera-tion. Airstream surfaces of the air-distribution system down-stream of Filter Bank No. 2, shall comply with Section 5.5 ofANSI/ASHRAE Standard 62.1-2007. The air-distributionsystem shall be provided with access doors, panels, or othermeans to allow convenient access for inspection and cleaning.(For further information, see ANSI/ASHRAE Standard 62.1.)

6.7.2 Air-Distribution Devices. All air-distributiondevices shall meet the following requirements:

TABLE 6-1 Minimum Filter Efficiencies

Space Designation (According to Function)Filter Bank Number 1

(MERV)aFilter Bank Number 2

(MERV)a

Classes B and C surgery; inpatient and ambulatory diagnostic and therapeuticradiology; inpatient delivery and recovery spaces

7 14

Inpatient care, treatment, and diagnosis, and those spaces providing direct service or clean supplies and clean processing (except as noted below);

AII (rooms)7 14

Protective environment rooms (PE) 7 17 (HEPA)c

Laboratories; Class A surgery and associated semi-restricted spaces 13b N/R*

Administrative; bulk storage; soiled holding spaces; food preparation spaces; and laundries

7 N/R

All other outpatient spaces 7 N/R

Skilled nursing facilities 7 N/R

* NR = not requiredNote a: The minimum efficiency reporting value (MERV) is based on the method of testing described in ANSI/ASHRAE Standard 52.2-2007, Method of Testing General Ventilation

Air-Cleaning Devices for Removal Efficiency by Particle Size (see Informative Annex B: Bibliography).Note b: Additional prefilters may be used to reduce maintenance for filters with efficiencies higher than MERV 7.Note c: Filter Bank No. 2 may be a MERV 14 if a MERV 17 tertiary terminal filter is provided for these spaces.

TABLE 6-2 Supply Air Outlets

Space Designation (According to Function) Supply Air Outlet Classificationa

All class A, B, and C surgeriesb Primary supply diffusers Group E, non-aspiratingadditional supply diffusers, Group E

Protective environment (PE) rooms Group E, non-aspirating

Wound intensive care units (burn units) Group E, non-aspirating

Trauma rooms (crisis or shock) Group E, non-aspirating

AII rooms Group A or Group E

All other spaces Group A or Group E

Note a: Refer to 2005 ASHRAE Handbook—Fundamentals, Chapter 35, for definitions related to outlet classification and performance (see Informative Annex B: Bibliography). Note b: Surgeons may require alternate air-distribution systems for some specialized surgeries. Such systems shall be considered acceptable if they meet or exceed the requirements

of this standard.


a. Surfaces of air-distribution devices shall be suitable forcleaning. Supply air outlets in accordance with Table 6-2shall be used.

b. The supply diffusers in Classes B and C surgeries shall bedesigned and installed to allow for internal cleaning.

c. Psychiatric, seclusion, and holding-patient rooms shall bedesigned with security diffusers, grilles, and registers.

7. SPACE VENTILATION

The ventilation requirements of this standard are mini-mums that provide control of environmental comfort, asepsis,and odor in health care facilities. However, because they areminimum requirements and because of the diversity of thepopulation and variations in susceptibility and sensitivity,these requirements do not provide assured protection fromdiscomfort, airborne transmission of contagions, and odors.

7.1 General Requirements. The following generalrequirements shall apply for space ventilation:

1. Spaces shall be ventilated according to Table 7-1.

a. Design of the ventilation system shall provide airmovement that is generally from clean to lessclean areas. If any form of variable-air-volume orload-shedding system is used for energy conser-vation, it shall not compromise the pressure bal-ancing relationships or the minimum air changesrequired by the table. See Table 7-1 note (t) foradditional information.

b. The ventilation rates in this table are intended toprovide for comfort as well as for asepsis andodor control in areas of a health care facility thatdirectly affect patient care. The air change ratesspecified are for supply in positive pressurerooms and for exhaust in negative pressurerooms. Ventilation rates for many areas not speci-fied here can be found in ANSI/ASHRAE Stan-dard 62.1 (see Informative Annex B:Bibliography). Where areas with prescribed ratesin both Standard 62.1-2007 and Table 7-1 of thisstandard exist, the higher of the two air changerates shall be used.

c. For design purposes, the minimum number oftotal air changes indicated shall be either sup-plied for positive pressure rooms or exhaustedfor negative pressure rooms. For spaces thatrequire a positive or negative pressure relation-ship, the number of air changes can be reducedwhen the space is unoccupied, provided that therequired pressure relationship to adjoiningspaces is maintained while the space is unoccu-pied and that the minimum number of airchanges indicated is reestablished anytime thespace becomes occupied. Air change rates inexcess of the minimum values are expected insome cases in order to maintain room tempera-

ture and humidity conditions based upon thespace cooling or heating load.

2. Air filtration for spaces shall comply with Table 6-1.3. Supply air outlets for spaces shall comply with Table 6-2.4. In AII rooms, protective environment rooms, wound inten-

sive care units (burn units), and rooms for all classes ofsurgery, heating with supply air or radiant panels that meetthe requirements of Section 6.5.3 shall be provided.

7.2 Additional Room Specific Requirements

7.2.1 Airborne Infection Isolation (AII) Rooms. Venti-lation for AII rooms shall meet the following requirementswhenever an infectious patient occupies the room:

a. Each AII room shall comply with requirements of Tables6-1, 6-2, and 7-1. AII rooms shall have a permanentlyinstalled device and/or mechanism to constantly monitorthe differential air pressure between the room and adja-cent spaces of the room when occupied by patients withan airborne infectious disease. A local visual means shallbe provided to indicate whenever negative differentialpressure is not maintained.

b. All air from the AII room shall be exhausted directly tothe outdoors.

Exception: AII rooms that are retrofitted from stan-dard patient rooms from which it is impractical toexhaust directly outdoors may be ventilated with recir-culated air from the room's exhaust, provided that the airfirst passes through a HEPA (MERV 17) filter.

c. All exhaust air from the AII rooms, associated anterooms,and associated toilet rooms shall be discharged directly tothe outdoors without mixing with exhaust air from anyother non-AII room or exhaust system.

d. Exhaust air grilles or registers in the patient room shall belocated directly above the patient bed on the ceiling or onthe wall near the head of the bed unless it can be demon-strated that such a location is not practical.

e. The room envelope shall be sealed to limit leakage airflow at 0.01 in. wc (2.5 Pa) differential pressure across theenvelope.

f. Differential pressure between AII rooms and adjacentspaces that have a different function shall be a minimumof –0.01 in. wc (–2.5 Pa).

7.2.2 Protective Environment (PE) Rooms. Ventilationfor PE rooms shall meet the following requirements:

a. The room envelope shall be sealed to limit leakage airflow at 0.01 in. wc (2.5 Pa) differential pressure across theenvelope.

b. Each PE room shall comply with the requirements ofTables 6-1, 6-2, and 7-1. PE rooms shall have a perma-nently installed device and/or mechanism to constantlymonitor the differential air pressure between the roomand adjacent spaces of the room when occupied bypatients requiring a protective environment. A local visualmeans shall be provided to indicate whenever positivedifferential pressure is not maintained.


TAB

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7-1

Des

ign

Par

amet

ers

Fun

ctio

n of

Spa

ce

Pre

ssur

eR

elat

ions

hip

to

Adj

acen

t A

reas

(n

)

Min

imum

Out

door

ach

Min

imum

To

tal a

ch

All

Roo

m A

ir

Exh

aust

ed

Dir

ectl

yto

Out

door

s (j

)

Air

Rec

ircu

late

d b

y M

ean

s of

R

oom

Uni

ts (a

)

RH

(k)

,%

Des

ign

Tem

pera

ture

(l)

,°F

/°C

SU

RG

ER

Y A

ND

CR

ITIC

AL

CA

RE

Cla

sses

B a

nd C

ope

rati

ng r

oom

s, (

m),

(n)

, (o)

Pos

itiv

e4

20N

/RN

o30

–60

68–7

5/20

–24

Ope

rati

ng/s

urgi

cal c

ysto

scop

ic r

oom

s, (

m),

(n)

(o)

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itiv

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68–7

5/20

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Del

iver

y ro

om (

Cae

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(m),

(n)

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Pos

itiv

e4

20N

/RN

o30

–60

68–7

5/20

–24

Sub

ster

ile s

ervi

ce a

rea

N/R

26

N/R

No

N/R

N/R

Rec

over

y ro

om

N/R

26

N/R

No

30–6

070

–75/

21–2

4

Cri

tica

l and

inte

nsiv

e ca

re

Pos

itiv

e2

6N

/RN

o30

–60

70–7

5/21

–24

Wou

nd in

tens

ive

care

(bu

rn u

nit)

Pos

itiv

e2

6N

/RN

o40

–60

70–7

5/21

–24

New

born

inte

nsiv

e ca

reP

osit

ive

26

N/R

No

30–6

070

–75/

21–2

4

Tre

atm

ent r

oom

(p)

N/R

26

N/R

N/R

30–6

070

–75/

21–2

4

Tra

uma

room

(cr

isis

or

shoc

k) (

c)

Pos

itiv

e3

15N

/RN

o30

–60

70–7

5/21

–24

Med

ical

/ane

sthe

sia

gas

stor

age

(r)

Neg

ativ

eN

/R8

Yes

N/R

N/R

N/R

Las

er e

ye r

oom

Pos

itiv

e3

15N

/RN

o30

–60

70–7

5/21

–24

ER

wai

ting

roo

ms

(q)

Neg

ativ

e2

12Y

esN

/Rm

ax 6

570

–75/

21–2

4

Tri

age

Neg

ativ

e2

12Y

es

N/R

max

60

70–7

5/21

–24

ER

dec

onta

min

atio

nN

egat

ive

212

Yes

No

N/R

N/R

Rad

iolo

gy w

aiti

ng r

oom

s (q

)N

egat

ive

212

Yes

N

/Rm

ax 6

070

–75/

21–2

4

Cla

ss A

Ope

rati

ng/P

roce

dure

roo

m (

o), (

d)P

osit

ive

315

N/R

No

30–6

070

–75/

21–2

4

INPA

TIE

NT

NU

RS

ING

Pat

ient

roo

m (

s)N

/R2

6N

/RN

/Rm

ax 6

070

–75/

21–2

4

Toil

et r

oom

N

egat

ive

N/R

10Y

esN

oN

/RN

/R

New

born

nur

sery

sui

te

N/R

26

N/R

No

30–6

072

–78/

22–2

6

Pro

tect

ive

envi

ronm

ent r

oom

(f)

, (n)

, (t)

Pos

itiv

e2

12N

/RN

om

ax 6

070

–75/

21–2

4

AII

roo

m (

e), (

n), (

u)N

egat

ive

212

Yes

N

om

ax 6

070

–75/

21–2

4

AII

isol

atio

n an

tero

om (

t) (

u)N

/RN

/R10

Yes

No

N/R

N/R

Lab

or/d

eliv

ery/

reco

very

/pos

tpar

tum

(L

DR

P)

(s)

N/R

26

N/R

N/R

max

60

70–7

5/21

–24

Lab

or/d

eliv

ery/

reco

very

(L

DR

) (s

)N

/R2

6N

/RN

/Rm

ax 6

070

–75/

21–2

4

Not

e: N

/R =

no

requ

irem

ent


Fun

ctio

n of

Spa

ce

Pre

ssur

eR

elat

ions

hip

to

Adj

acen

t A

reas

(n

)

Min

imum

Out

door

ach

Min

imum

To

tal a

ch

All

Roo

m A

ir

Exh

aust

ed

Dir

ectl

yto

Out

door

s (j

)

Air

Rec

ircu

late

d b

y M

ean

s of

R

oom

Uni

ts (a

)

RH

(k)

,%

Des

ign

Tem

pera

ture

(l)

,°F

/°C

Cor

rido

rN

/RN

/R2

N/R

N/R

N/R

N/R

SK

ILL

ED

NU

RS

ING

FA

CIL

ITY

Res

iden

t roo

mN

/R2

2N

/RN

/RN

/R70

–75/

21–2

4

Res

iden

t gat

heri

ng/a

ctiv

ity/

dini

ngN

/R4

4N

/RN

/RN

/R70

–75/

21–2

4

Phy

sica

l the

rapy

Neg

ativ

e2

6N

/RN

/RN

/R70

–75/

21–2

4

Occ

upat

iona

l the

rapy

N/R

26

N/R

N/R

N/R

70–7

5/21

–24

Bat

hing

roo

mN

egat

ive

N/R

10Y

esN

/RN

/R70

–75/

21–2

4

RA

DIO

LO

GY

(v)

X-r

ay (

diag

nost

ic a

nd tr

eatm

ent)

N/R

26

N/R

N/R

max

60

72–7

8/22

–26

X-r

ay (

surg

ery/

crit

ical

car

e an

d ca

thet

eriz

atio

n)P

osit

ive

315

N/R

No

max

60

70–7

5/21

–24

Dar

kroo

m (

g)N

egat

ive

210

Yes

N

oN

/RN

/R

DIA

GN

OS

TIC

AN

D T

RE

AT

ME

NT

Bro

ncho

scop

y, s

putu

m c

olle

ctio

n,an

d pe

ntam

idin

e ad

min

istr

atio

n (n

)N

egat

ive

212

Yes

No

N/R

68–7

3/20

–23

Lab

orat

ory,

gen

eral

(v)

Neg

ativ

e2

6N

/R

No

N/R

70–7

5/21

–24

Lab

orat

ory,

bac

teri

olog

y (v

)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

bio

chem

istr

y (v

)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

cyt

olog

y (v

)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

gla

ssw

ashi

ngN

egat

ive

210

Yes

No

N/R

N/R

Lab

orat

ory,

his

tolo

gy (

v)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

mic

robi

olog

y (v

)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

nuc

lear

med

icin

e (v

)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

pat

holo

gy (

v)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

ser

olog

y (v

)N

egat

ive

26

Yes

No

N/R

70–7

5/21

–24

Lab

orat

ory,

ste

rili

zing

Neg

ativ

e2

10Y

esN

oN

/R70

–75/

21–2

4

Lab

orat

ory,

med

ia tr

ansf

er (

v)P

osit

ive

24

N/R

No

N/R

70–7

5/21

–24

Aut

opsy

roo

m (

n)N

egat

ive

212

Yes

No

N/R

68–7

5/20

–24

Non

refr

iger

ated

bod

y-ho

ldin

g ro

om (

h)N

egat

ive

N/R

10Y

esN

oN

/R70

–75/

21–2

4

Phar

mac

y (b

)P

osit

ive

24

N/R

N/R

N/R

N/R

Not

e: N

/R =

no

requ

irem

ent

TAB

LE

7-1

Des

ign

Par

amet

ers


Fun

ctio

n of

Spa

ce

Pre

ssur

eR

elat

ions

hip

to

Adj

acen

t A

reas

(n

)

Min

imum

Out

door

ach

Min

imum

To

tal a

ch

All

Roo

m A

ir

Exh

aust

ed

Dir

ectl

yto

Out

door

s (j

)

Air

Rec

ircu

late

d b

y M

ean

s of

R

oom

Uni

ts (a

)

RH

(k)

,%

Des

ign

Tem

pera

ture

(l)

,°F

/°C

Exa

min

atio

n ro

om

N/R

26

N/R

N/R

max

60

70–7

5/21

–24

Med

icat

ion

room

Pos

itiv

e2

4N

/RN

/Rm

ax 6

070

–75/

21–2

4

End

osco

pyP

osit

ive

215

N/R

No

30-6

068

–73/

20–2

3

End

osco

pe c

lean

ing

Neg

ativ

e2

10Y

esN

oN

/RN

/R

Tre

atm

ent r

oom

N/R

26

N/R

N/R

max

60

70–7

5/21

–24

Hyd

roth

erap

yN

egat

ive

26

N/R

N/R

N/R

72–8

0/22

–27

Phy

sica

l the

rapy

Neg

ativ

e2

6N

/RN

/RM

ax 6

572

–80/

22–2

7

ST

ER

ILIZ

ING

Ste

rili

zer

equi

pmen

t roo

mN

egat

ive

N/R

10Y

esN

oN

/RN

/R

CE

NT

RA

L M

ED

ICA

L A

ND

SU

RG

ICA

L S

UP

PLY

S

oile

d or

dec

onta

min

atio

n ro

omN

egat

ive

26

Yes

No

N/R

72–7

8/22

–26

C

lean

wor

kroo

mP

osit

ive

24

N/R

No

max

60

72–7

8/22

–26

S

teri

le s

tora

geP

osit

ive

24

N/R

N/R

max

60

72–7

8/22

–26

SE

RV

ICE

Food

pre

para

tion

cen

ter

(i)

N/R

210

N/R

No

N/R

72–7

8/22

–26

War

ewas

hing

Neg

ativ

eN

/R10

Yes

No

N/R

N/R

Die

tary

sto

rage

N/R

N/R

2N

/RN

oN

/R72

–78/

22–2

6

Lau

ndry

, gen

eral

Neg

ativ

e2

10Y

esN

oN

/RN

/R

Soil

ed li

nen

sort

ing

and

stor

age

Neg

ativ

eN

/R10

Yes

No

N/R

N/R

Cle

an li

nen

stor

age

Pos

itiv

eN

/R2

N/R

N/R

N/R

72–7

8/22

–26

Lin

en a

nd tr

ash

chut

e ro

omN

egat

ive

N/R

10Y

esN

oN

/RN

/R

Bed

pan

room

Neg

ativ

eN

/R10

Yes

No

N/R

N/R

Bat

hroo

mN

egat

ive

N/R

10Y

esN

oN

/R72

–78/

22–2

6

Jani

tor's

clo

set

Neg

ativ

eN

/R10

Yes

No

N/R

N/R

SU

PP

OR

T S

PAC

E

Soi

led

wor

kroo

m o

r so

iled

hol

ding

Neg

ativ

e2

10Y

esN

oN

/RN

/R

Cle

an w

orkr

oom

or

clea

n ho

ldin

gP

osit

ive

24

N/R

N/R

N/R

N/R

Haz

ardo

us m

ater

ial s

tora

geN

egat

ive

210

Yes

N

oN

/RN

/R

Not

e: N

/R =

no

requ

irem

ent

TAB

LE

7-1

Des

ign

Par

amet

ers


Tabl

e 7-

1 N

otes

:

a.R

ecir

cula

ting

room

HV

AC

uni

ts (

with

hea

ting

or c

oolin

g co

ils)

are

acce

ptab

le to

ach

ieve

the

requ

ired

air

cha

nge

rate

s. B

ecau

se o

f th

e cl

eani

ng d

iffi

culty

and

the

pote

ntia

l for

bui

ldup

of

cont

amin

a-tio

n, re

circ

ulat

ing

room

uni

ts s

hall

not b

e us

ed in

are

as m

arke

d “N

o.”

Isol

atio

n an

d in

tens

ive

care

uni

t roo

ms

may

be

vent

ilat

ed b

y re

heat

indu

ctio

n un

its in

whi

ch o

nly

the

prim

ary

air s

uppl

ied

from

ace

ntra

l sys

tem

pas

ses

thro

ugh

the

rehe

at u

nit.

Gra

vity

-typ

e he

atin

g or

coo

ling

units

, suc

h as

rad

iato

rs o

r co

nvec

tors

, sha

ll no

t be

used

in o

pera

ting

room

s an

d ot

her

spec

ial c

are

area

s.b.

Phar

mac

y co

mpo

undi

ng a

reas

may

hav

e ad

ditio

nal a

ir c

hang

e an

d fi

lteri

ng r

equi

rem

ents

bey

ond

the

min

imum

of

this

tab

le d

epen

ding

on

the

type

of

phar

mac

y, th

e re

gula

tory

req

uire

men

ts (

whi

chm

ay in

clud

e ad

optio

n of

USP

797

), th

e as

soci

ated

leve

l of

risk

of

the

wor

k (s

ee U

SP 7

97),

and

the

equi

pmen

t util

ized

in th

e sp

aces

.c.

The

term

tra

uma

room

as

used

her

ein

is a

fir

st a

id r

oom

and

/or

emer

genc

y ro

om u

sed

for

gene

ral i

niti

al tr

eatm

ent o

f ac

cide

nt v

icti

ms.

The

ope

rati

ng r

oom

wit

hin

the

trau

ma

cent

er th

at is

rou

-ti

nely

use

d fo

r em

erge

ncy

surg

ery

is c

onsi

dere

d to

be

an o

pera

ting

roo

m b

y th

is S

tand

ard.

d.Pr

essu

re r

elat

ions

hips

nee

d no

t be

mai

ntai

ned

whe

n th

e ro

om is

uno

ccup

ied.

e.S

ome

isol

atio

n ro

oms

may

be

prov

ided

wit

h a

sepa

rate

ant

eroo

m, b

ut a

n an

te r

oom

is

not

requ

ired

by

this

sta

ndar

d.

f.Pr

otec

tive

envi

ronm

ent r

oom

s ar

e th

ose

used

for

hig

h-ri

sk im

mun

ocom

prom

ised

pat

ient

s. S

uch

room

s ar

e po

sitiv

ely

pres

suri

zed

rela

tive

to a

ll ad

join

ing

spac

es to

pro

tect

the

pati

ent.

g.E

xcep

tion:

All

air n

eed

not b

e ex

haus

ted

if d

arkr

oom

equ

ipm

ent h

as a

sca

veng

ing

exha

ust d

uct a

ttach

ed a

nd m

eets

ven

tilat

ion

stan

dard

s re

gard

ing

NIO

SH, O

SHA

, and

loca

l em

ploy

ee e

xpos

ure

limits

.2, 3

h.A

non

refr

iger

ated

bod

y-ho

ldin

g ro

om is

app

licab

le o

nly

to fa

cilit

ies

that

do

not p

erfo

rm a

utop

sies

on-

site

and

use

the

spac

e fo

r sh

ort p

erio

ds w

hile

wai

ting

for

the

body

to b

e tr

ansf

erre

d.i.

Min

imum

tota

l air

cha

nges

per

hou

r (a

ch)

shal

l be

that

req

uire

d to

pro

vide

pro

per

mak

eup

air

to k

itche

n ex

haus

t sys

tem

s as

spe

cifi

ed in

AN

SI/A

SHR

AE

Sta

ndar

d 15

4.4 I

n so

me

case

s, e

xces

s ex

fil-

trat

ion

or in

filtr

atio

n to

or

from

exi

t cor

rido

rs c

ompr

omis

es th

e ex

it c

orri

dor

rest

rict

ions

of

NF

PA 9

0A,5 th

e pr

essu

re r

equi

rem

ents

of

NF

PA 9

6,6 o

r th

e m

axim

um d

efin

ed in

the

tabl

e. D

urin

g op

er-

atio

n, a

red

uctio

n to

the

num

ber

of a

ir c

hang

es to

any

ext

ent r

equi

red

for

odor

con

trol

sha

ll b

e pe

rmit

ted

whe

n th

e sp

ace

is n

ot in

use

. (Se

e A

IA [

2006

] in

Info

rmat

ive

Ann

ex B

: Bib

liogr

aphy

.)j.

In s

ome

area

s w

ith p

oten

tial c

onta

min

atio

n an

d/or

odo

r pr

oble

ms,

exh

aust

air

sha

ll be

dis

char

ged

dire

ctly

to th

e ou

tdoo

rs a

nd n

ot r

ecir

cula

ted

to o

ther

are

as. I

ndiv

idua

l cir

cum

stan

ces

may

requ

ire

spe-

cial

con

side

ratio

n fo

r ai

r ex

haus

ted

to th

e ou

tdoo

rs, f

or e

xam

ple,

inte

nsiv

e ca

re u

nits

in w

hich

pat

ient

s w

ith p

ulm

onar

y in

fect

ion

are

trea

ted

and

room

s fo

r bur

n pa

tient

s. T

o sa

tisf

y ex

haus

t nee

ds, c

on-

stan

t rep

lace

men

t air

fro

m th

e ou

tdoo

rs is

nec

essa

ry w

hen

the

syst

em is

in o

pera

tion.

k.T

he R

H r

ange

s lis

ted

are

the

min

imum

and

max

imum

lim

its w

here

con

trol

is s

peci

fica

lly n

eede

d.

l.Sy

stem

s sh

all b

e ca

pabl

e of

mai

ntai

ning

the

room

s w

ithin

the

rang

e du

ring

nor

mal

ope

ratio

n. L

ower

or h

ighe

r tem

pera

ture

sha

ll be

per

mitt

ed w

hen

patie

nts’

com

fort

and

/or

med

ical

con

ditio

ns re

quir

eth

ose

cond

ition

s.m

.N

atio

nal

Inst

itute

for

Occ

upat

iona

l S

afet

y an

d H

ealth

(N

IOS

H)

crite

ria

docu

men

ts r

egar

ding

occ

upat

iona

l ex

posu

re t

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aste

ane

sthe

tic g

ases

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ors,

and

con

trol

of

occu

patio

nal

expo

sure

to

nitr

ous

oxid

e7 indi

cate

a n

eed

for

both

loca

l exh

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(sc

aven

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) sy

stem

s an

d ge

nera

l ven

tilat

ion

of th

e ar

eas

in w

hich

the

resp

ectiv

e ga

ses

are

utili

zed.

Ref

er to

NF

PA 9

9 fo

r ot

her

requ

irem

ents

.8

n.If

mon

itori

ng d

evic

e al

arm

s ar

e in

stal

led,

allo

wan

ces

shal

l be

mad

e to

pre

vent

nui

sanc

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s. S

hort

term

exc

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ons

from

req

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essu

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elat

ions

hips

sha

ll be

allo

wed

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le d

oors

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orte

mpo

rari

ly o

pen.

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ple

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uch

as s

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ail,

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or

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ters

trip

sha

ll be

per

mitt

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or v

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of a

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tion.

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s w

ith H

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filt

ers

shal

l be

per-

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n ex

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cilit

ies

as in

teri

m, s

uppl

emen

tal e

nvir

onm

enta

l co

ntro

ls t

o m

eet r

equi

rem

ents

for

the

cont

rol

of a

irbo

rne

infe

ctio

us a

gent

s. T

he d

esig

n of

eith

er p

orta

ble

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ixed

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tem

s sh

ould

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ent s

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atio

n an

d sh

ort c

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of

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low

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des

ign

of s

uch

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shal

l als

o al

low

for

eas

y ac

cess

for

sch

edul

ed p

reve

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ive

mai

nten

ance

and

cle

anin

g.o.

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eons

or

surg

ical

pro

cedu

res

may

req

uire

roo

m te

mpe

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res,

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tilat

ion

rate

s, h

umid

ity r

ange

s, a

nd/o

r ai

r di

stri

butio

n m

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ds th

at e

xcee

d th

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inim

um in

dica

ted

rang

es.

p.T

reat

men

t roo

ms

used

for

bron

chos

copy

sha

ll be

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ted

as b

ronc

hosc

opy

room

s. T

reat

men

t roo

ms

used

for

proc

edur

es w

ith n

itrou

s ox

ide

shal

l con

tain

pro

visi

ons

for

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ustin

g an

esth

etic

was

te g

ases

.q.

In a

rec

ircu

latin

g ve

ntila

tion

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em, H

EPA

filte

rs s

hall

be p

erm

itted

inst

ead

of e

xhau

stin

g th

e ai

r fr

om th

ese

spac

es to

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outd

oors

pro

vide

d th

e re

turn

air

pas

ses

thro

ugh

the

HE

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lter

s be

fore

it is

intr

oduc

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to a

ny o

ther

spa

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s re

quir

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t app

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only

to w

aitin

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oms

prog

ram

med

to h

old

patie

nts

awai

ting

ches

t x-r

ays

for

diag

nosi

s of

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pira

tory

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ease

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See

NF

PA 9

9 fo

r fu

rthe

r re

quir

emen

ts.8

s.Fo

r pa

tient

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ms,

labo

r/de

liver

y/re

cove

ry r

oom

s, a

nd la

bor/

deliv

ery/

reco

very

/pos

tpar

tum

roo

ms,

fou

r to

tal a

ch s

hall

be p

erm

itted

whe

n su

pple

men

tal h

eatin

g an

d/or

coo

ling

syst

ems

(rad

iant

hea

ting

and

cool

ing,

bas

eboa

rd h

eatin

g, e

tc.)

are

used

.t.

The

pro

tect

ive

envi

ronm

ent

airf

low

des

ign

spec

ific

atio

ns p

rote

ct th

e pa

tient

fro

m c

omm

on e

nvir

onm

enta

l air

born

e in

fect

ious

mic

robe

s (i

.e.,

Asp

ergi

llus

spor

es).

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ircu

latio

n H

EPA

filt

ers

shal

l be

perm

itted

to i

ncre

ase

the

equi

vale

nt r

oom

air

exc

hang

es; h

owev

er, t

he o

utdo

or a

ir c

hang

es a

re s

till r

equi

red.

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stan

t vol

ume

airf

low

is r

equi

red

for

cons

iste

nt v

entil

atio

n fo

r th

e pr

otec

ted

envi

ron-

men

t. If

the

desi

gn c

rite

ria

indi

cate

that

AII

is n

eces

sary

for

pro

tect

ive

envi

ronm

ent p

atie

nts,

an

ante

room

sho

uld

be p

rovi

ded.

Roo

ms

with

rev

ersi

ble

airf

low

pro

visi

ons

for

the

purp

ose

of s

witc

hing

betw

een

prot

ectiv

e en

viro

nmen

t and

AII

fun

ctio

ns s

hall

not b

e pe

rmit

ted.

u.T

he A

II r

oom

des

crib

ed in

this

sta

ndar

d sh

all b

e us

ed fo

r iso

latin

g th

e ai

rbor

ne s

prea

d of

infe

ctio

us d

isea

ses,

suc

h as

mea

sles

, var

icel

la, o

r tu

berc

ulos

is. T

he d

esig

n of

AII

roo

ms

shal

l inc

lude

the

pro-

visi

on fo

r nor

mal

pat

ient

car

e du

ring

per

iods

not

requ

irin

g is

olat

ion

prec

autio

ns. S

uppl

emen

tal r

ecir

cula

ting

devi

ces

usin

g H

EPA

filte

rs s

hall

be p

erm

itted

in th

e pa

tient

roo

m to

incr

ease

the

equi

vale

ntro

om a

ir e

xcha

nges

; how

ever

, the

out

door

air

cha

nges

are

stil

l req

uire

d. A

II r

oom

s th

at a

re r

etro

fitte

d fr

om s

tand

ard

patie

nt r

oom

s fr

om w

hich

it is

impr

actic

al to

exh

aust

dir

ectly

out

side

may

be

reci

r-cu

late

d w

ith a

ir f

rom

the

AII

roo

m, p

rovi

ded

that

the

air

firs

t pas

ses

thro

ugh

a H

EPA

filt

er. H

EPA

filt

ered

exh

aust

air

fro

m A

II r

oom

s m

ay m

ix w

ith e

xhau

st a

ir th

at s

erve

s no

n-A

II s

pace

s pr

ior

tobe

ing

disc

harg

ed d

irec

tly o

utdo

ors.

Roo

ms

with

rev

ersi

ble

airf

low

pro

visi

ons

for

the

purp

ose

of s

wit

chin

g be

twee

n pr

otec

tive

envi

ronm

ent a

nd A

II fu

nctio

ns s

hall

not b

e pe

rmitt

ed. S

ee th

e gu

idel

ines

in I

nfor

mat

ive

Ann

ex B

: Bib

liogr

aphy

for

mor

e in

form

atio

n.v.

Whe

n re

quir

ed, a

ppro

pria

te h

oods

and

exh

aust

dev

ices

for

the

rem

oval

of

noxi

ous

gase

s or

che

mic

al v

apor

s sh

all b

e pr

ovid

ed in

acc

orda

nce

wit

h N

FPA

99.

8


c. Air distribution patterns within the protective environ-ment room shall conform to the following: • Supply air diffusers shall be above the patient bed,

unless it can be demonstrated that such a location isnot practical. Diffuser design shall limit air velocityat the patient bed to reduce patient discomfort. (SeeANSI/ASHRAE Standard 55-2004, Thermal Envi-ronmental Conditions for Human Occupancy, inInformative Annex B: Bibliography.)

• Return/exhaust grilles or registers shall be locatednear the patient room door.

d. Differential pressure between any dissimilar adjacentspaces shall be a minimum of +0.01 in. wc (+2.5 Pa).

e. PE rooms retrofitted from standard patient rooms may beventilated with recirculated air, provided that air firstpasses through a HEPA filter and the room complies withparts “a” through “d” of this section.

7.3 Critical Care Units

7.3.1 Wound Intensive Care Units (Burn Units). Burnunit patient rooms that require humidifiers to comply withTable 7-1 shall be provided with individual humidity control.

7.4 Surgery Rooms

7.4.1 Class B and C Operating Rooms. Operating roomsshall be maintained at a positive pressure with respect to alladjoining spaces at all times. A pressure differential shall bemaintained at a value of at least +0.01 in. wc (2.5 Pa). Oper-ating rooms shall be provided with primary supply diffusersthat are designed as follows:

a. The airflow shall be unidirectional, downwards, and theaverage velocity of the diffusers shall be 25 to 35 cfm/ft2

(127 L/s/m2 to 178 L/s/m2). The diffusers shall be concen-trated to provide an airflow pattern over the patient andsurgical team. (see Memarzadeh [2002] and Memarzadeh[2004] in Informative Annex B: Bibliography.)

b. The area of the primary supply diffuser array shall extenda minimum of 12 in. (305 mm) beyond the footprint ofthe surgical table on each side. No more than 30% of theprimary supply diffuser array area shall be used for non-diffuser uses such as lights, gas columns, etc. Additionalsupply diffusers may be required to provide additionalventilation to the operating room to achieve the environ-mental requirements of Table 7-1 relating to temperature,humidity, etc.

The room shall be provided with at least two low sidewallreturn or exhaust grilles spaced at opposite corners or as farapart as possible, with the bottom of these grilles installedapproximately 8 in. (203 mm) above the floor.

7.4.2 Sterilization Rooms. Steam that escapes from asteam sterilizer shall be exhausted using an exhaust hood orother suitable means. Ethylene oxide that escapes from a gassterilizer shall be exhausted using an exhaust hood or othersuitable means.

7.4.3 Imaging Procedure Rooms. If invasive proceduresoccur in this type of room, ventilation shall be provided in

accordance with the ventilation requirements for Class A sur-gery. If anesthetic gases are administered, ventilation shall beprovided in accordance with the ventilation requirements forClass B or C surgery.

7.5 Support Spaces

7.5.1 Morgue and Autopsy Rooms. Low sidewallexhaust grilles shall be provided unless exhaust air is removedthrough an autopsy table designed for this purpose. All exhaustair from autopsy, nonrefrigerated body-holding, and morguerooms shall be discharged directly to the outdoors withoutmixing with air from any other room or exhaust system.

8. PLANNING, CONSTRUCTION, ANDSYSTEM STARTUP

8.1 Overview. For HVAC systems serving surgery and crit-ical care spaces, compliance with this standard requires prep-aration of an acceptance testing plan.

8.2 Planning for the HVAC Services in a New Facility.Design documents for new construction shall meet the follow-ing requirements:

a. General Mechanical Equipment Rooms. The access tomechanical rooms shall be planned to avoid the intrusionof maintenance personnel into surgical and critical carepatient spaces.

b. Mechanical Room Layout. Mechanical room layoutshall include sufficient space for access to equipment foroperation, maintenance, and replacement. Floors inmechanical rooms shall be sealed, including sealingaround all penetrations, when they are above surgicalsuites and critical care.

c. Maintenance/Repair Personnel Access. Safe and practicalmeans of accessing equipment shall be provided. Clear-ance is required at all service points to mechanical equip-ment to allow personnel access and working space. Theaccess to mechanical equipment shall be planned to makeit unnecessary for maintenance personnel to intrude intosurgical or critical care rooms.

d. Cooling Towers. Cooling towers shall be located so thatdrift is directed away from air-handling unit intakes. Theyshall meet the requirements of Section 6.3.2.

8.3 Planning for the HVAC Services in an Existing Facility.If any existing air-handling equipment is reused, the designershall evaluate the capacity of the equipment to determinewhether it will meet the requirements of this standard for theremodeled space.

8.4 Planning for Infection Control During Remodelingof an Existing Facility. Prior to beginning modifications orremodeling of HVAC systems in an existing facility, an ownershall conduct an infection control risk assessment (ICRA).The ICRA shall establish those procedures required to mini-mize the disruption of facility operation and the distributionof dust, odors and particulates.


8.5 Documentation of New or Remodeled HVAC Sys-tems. Owners shall retain an acceptance testing report for theirfiles. In addition, the design shall include requirements foroperations and maintenance staff training that is sufficient forthe staff to keep all HVAC equipment in a condition that willmaintain the original design intent for ventilation. Training ofoperating staff shall include an explanation of the designintent. The training materials shall include, at a minimum, thefollowing:

a. O&M proceduresb. Temperature and pressure control operation in all modesc. Acceptable tolerances for system temperatures and

pressuresd. Procedures for operations under emergency power or

other abnormal conditions that have been considered inthe facility design.

8.6 Duct Cleanliness. The duct supply system shall meetthe following requirements for cleanliness:

a. The duct system shall be free of construction debris. Newsupply duct system installations shall comply with level“B,” the Intermediate Level of SMACNA Duct Cleanli-ness for New Construction Guidelines.9

b. The supply diffusers in the Class B & C operating roomsshall be opened and cleaned before the space is used.

c. The permanent HVAC systems shall not be operatedunless protection from contamination of the air distribu-tion system is provided.

9. NORMATIVE REFERENCES1 Code of Federal Regulations: 21CFR 173.310 (April

1999), US Dept. of Health and Human Services, Foodand Drug Administration.

2DHHS (NIOSH) Publication No. 94-100 (NIOSH Alert)Controlling Exposures to Nitrous Oxide During Anes-thetic Administration, National Institute for Occupa-tional Safety and Health (CDC), Atlanta, GA.

3OSHA [1994]. Computerized information system. Wash-ington, DC: U.S. Department of Labor, OccupationalSafety and Health Administration.

4ANSI/ASHRAE Standard 154-2003 Ventilation for Com-mercial Cooking Operations, American Society of Heat-ing, Refrigerating and Air-Conditioning Engineers,Atlanta, GA.

5NFPA 90A. National Fire Protection Association 1 Battery-march Park, Quincy, MA 02169.

6NFPA 96. National Fire Protection Association 1 Battery-march Park, Quincy, MA 02169.

7NIOSH Critical Documents. National Institute for Occupa-tional Safety and Health, available at the Centers forDisease Control and Prevention (CDC) web site: http://www.cdc.gov/niosh/pubs/criteria_date_desc_nopubnumbers.html

8NFPA 99-2005: Standard for Health Care Facilities.National Fire Protection Association 1 BatterymarchPark, Quincy, Massachusetts USA 02169

9SMACNA Duct Cleanliness for New Construction Guide-lines, (2000), Chantilly, VA 20151.

(This annex is not part of this standard. It is merelyinformative and does not contain requirements necessaryfor conformance to the standard. It has not beenprocessed according to the ANSI requirements for astandard and may contain material that has not beensubject to public review or a consensus process.Unresolved objectors on informative material are notoffered the right to appeal at ASHRAE or ANSI.)

INFORMATIVE ANNEX A

A1. O&M IN HEALTH CARE FACILITIES

The following operations and maintenance proceduresare recommended for health care facilities.

A1.1 Operating Rooms. Each operating room should betested for positive pressure semi-annually or on an effectivepreventative maintenance schedule. When HEPA filters arepresent within the diffuser of operating rooms, the filtershould be replaced based on pressure drop.

A1.2 Protective Environment (PE) Rooms. PE roomsshould remain under positive pressure with respect to alladjoining rooms whenever an immunocompromised patient ispresent. PE rooms should be tested for positive pressure dailywhen an immunocompromised patient is present. WhenHEPA filters are present within the diffuser of protective envi-ronment rooms, the filter should be replaced based on pres-sure drop.

A1.3 Airborne Infection Isolation (AII) Rooms. AIIrooms should remain under negative pressure relative to alladjoining rooms whenever an infectious patient is present.They should be tested for negative pressure daily whenever aninfectious patient is present.

A1.4 Filters. Final filters and filter frames should be visu-ally inspected for pressure drop and for bypass monthly. Fil-ters should be replaced based on pressure drop with filters thatprovide the efficiencies specified in Table 6-1.

A2. SPECIAL MAINTENANCE FOR HVAC UNITS

The following special maintenance procedures arerecommended for health care facilities.

A2.1 Fan-Coil Unit and Heat Pumps. The fan-coil unitand heat pump filters serving patient rooms should beinspected monthly or on an effective preventative mainte-nance cycle for pressure drop and replaced when that pressuredrop causes a reduction in air flow. Fan-coil unit and heatpump drain pans under cooling coils should be cleanedmonthly, or on an effective preventative maintenance cycle.

A2.2 Fin-Tube Radiation Units, Induction Units andConvection Units. Fin-tube radiation units, induction unitsand convection units serving patient rooms should be cleanedquarterly, or on an effective preventative maintenance cycle.

A2.3 Fan-Powered Terminal Units. Fan-powered termi-nal unit filters serving patient rooms should be inspectedmonthly or on an effective preventative maintenance cycle forpressure drop and replaced when the pressure drop causes areduction in air flow.


(This annex is not part of this standard. It is merelyinformative and does not contain requirements necessaryfor conformance to the standard. It has not beenprocessed according to the ANSI requirements for astandard and may contain material that has not beensubject to public review or a consensus process.Unresolved objectors on informative material are notoffered the right to appeal at ASHRAE or ANSI.)

INFORMATIVE ANNEX BBIBLIOGRAPHY

ACS, 2000. Guidelines for Optimal Ambulatory SurgicalCare and Office-based Surgery. 3rd ed. American Col-lege of Surgeons, Chicago, IL 60611

AIA, 2006. The American Institute of Architects and TheFacilities Guidelines Institute. Guidelines for Designand Construction of Hospital and Health Care Facili-ties. American Institute of Architects Press, Washing-ton, DC 2006.

ASHRAE, 1999. Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by ParticleSize. ANSI/ASHRAE Standard 52.2-1999.

ASHRAE, 2003. 2003 ASHRAE Handbook-Applications,Chapter 7, Health Care Facilities. American Society ofHeating, Refrigerating, and Air-Conditioning Engi-neers, Inc., Atlanta GA.

ASHRAE, 2003. HVAC Design Manual for Hospitals andHealth Care Facilities, American Society of Heating,Refrigerating, and Air-Conditioning Engineers, Inc.,Atlanta GA.

ASHRAE, 2004. Thermal Environmental Conditions forHuman Occupancy, ANSI/ASHRAE Standard 55-2004.

ASHRAE, 2005. 2005 ASHRAE Handbook-Fundamentals,Chapter 35, Duct Design. American Society of Heating,Refrigerating, and Air-Conditioning Engineers, Inc.,Atlanta GA.

ASHRAE, 2007. Ventilation for Acceptable Indoor AirQuality, ANSI/ASHRAE Standard 62.1-2007. Ameri-can Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. Atlanta, GA.

CAN/CSA-Z317.2-01 Special Requirements for Heating,Ventilation, and Air Conditioning Systems in HealthCare Facilities September 2001.

CDC, 2005. Guidelines for Preventing the Transmission ofMycobacterium tuberculosis in Health-Care Facilities.Federal Register, 2005. Centers for Disease Control andPrevention, Atlanta, GA.

CDC, 2003. Guidelines for Environmental infection controlin health-care facilities. Morbidity and MortalityWeekly Report (MMWR), June 6, 2003. Centers forDisease Control and Prevention, Atlanta, GA.

Charles S. Hayden II, O.E. Johnston, R.T. Hughes, and P.A.Jensen, 1998. Air Volume Migration from Negative Pres-sure Isolation Rooms During Entry/Exit. Applied Occu-pational and Environmental Hygiene, 13(7): 518-527;1998.

Coogan, JJ, 1996. Effects of Surrounding Spaces on RoomsPressurized by Differential Flow Control. ASHRAETransactions 1996, V 102, Pt 1.

Hermans, RD. 2000. Health Care Facility Design Manual-Room Design. ASHRAE Transactions Vol. 106, Pt. 2

Lewis, J.R, 1987. Operating room air distribution effective-ness. ASHRAE Transactions 93(2):1191-1198.

Memarzadeh F and Manning A, 2002. “Comparison of oper-ating room ventilation systems in the protection of thesurgical site.”, ASHRAE Transactions, V.108, Pt. 2,2002.

Memarzadeh F and Jiang Z. 2004. “Effects of OperatingRoom Geometry and Ventilation System Parameter Vari-ations on the Protection of the Surgical Site”, IAQ 2004:Critical Operations: Supporting the Healing Environ-ment through IAQ Performance Standards.

Ninomura, P. and Judene Bartley, 2001. New VentilationGuidelines for Health-Care Facilities, ASHRAE Jour-nal, June 2001, Atlanta, GA

NFPA, 2005. Standard for Health Care Facilities. NFPA-99-2005. National Fire Protection Association 1 Battery-march Park, Quincy, Massachusetts USA 02169

SMACNA, Duct Cleanliness for New Construction Guide-lines.

USP-797, Guidebook to Pharmaceutical Compounding—Sterile Preparations, US Pharmacopeial Convention.

29 CFR Part 1910.1047, Occupational Exposure to EthyleneOxide.


NOTICE

INSTRUCTIONS FOR SUBMITTING A PROPOSED CHANGE TO THIS STANDARD UNDER CONTINUOUS MAINTENANCE

This standard is maintained under continuous maintenance procedures by a Standing Standard Project Committee (SSPC) forwhich the Standards Committee has established a documented program for regular publication of addenda or revisions, includ-ing procedures for timely, documented, consensus action on requests for change to any part of the standard. SSPC consider-ation will be given to proposed changes within 13 months of receipt by the manager of standards (MOS).

Proposed changes must be submitted to the MOS in the latest published format available from the MOS. However, the MOSmay accept proposed changes in an earlier published format if the MOS concludes that the differences are immaterial to theproposed change submittal. If the MOS concludes that a current form must be utilized, the proposer may be given up to20 additional days to resubmit the proposed changes in the current format.

ELECTRONIC PREPARATION/SUBMISSION OF FORM FOR PROPOSING CHANGES

An electronic version of each change, which must comply with the instructions in the Notice and the Form, is the preferredform of submittal to ASHRAE Headquarters at the address shown below. The electronic format facilitates both paper-basedand computer-based processing. Submittal in paper form is acceptable. The following instructions apply to change proposalssubmitted in electronic form.

Use the appropriate file format for your word processor and save the file in either a recent version of Microsoft Word (pre-ferred) or another commonly used word-processing program. Please save each change proposal file with a different name (forexample, “prop01.doc,” “prop02.doc,” etc.). If supplemental background documents to support changes submitted areincluded, it is preferred that they also be in electronic form as word-processed or scanned documents.

ASHRAE will accept the following as equivalent to the signature required on the change submittal form to convey non-exclusive copyright:

Files attached to an e-mail: Electronic signature on change submittal form (as a picture; *.tif, or *.wpg).

Files on a CD: Electronic signature on change submittal form (as a picture; *.tif, or *.wpg) or a letter with submitter’s signature accompanying the CD or sent by facsimile (single letter may cover all of proponent’s proposed changes).

Submit an e-mail or a CD containing the change proposal files to:Manager of Standards

ASHRAE1791 Tullie Circle, NE

Atlanta, GA 30329-2305E-mail: [email protected]

(Alternatively, mail paper versions to ASHRAE address or fax to 404-321-5478.)

The form and instructions for electronic submittal may be obtained from the Standards section of ASHRAE’s Home Page,www.ashrae.org, or by contacting a Standards Secretary, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. Phone: 404-636-8400. Fax: 404-321-5478. E-mail: [email protected].


FORM FOR SUBMITTAL OF PROPOSED CHANGE TO ANASHRAE STANDARD UNDER CONTINUOUS MAINTENANCE

NOTE: Use a separate form for each comment. Submittals (Microsoft Word preferred) may be attached to e-mail (preferred),submitted on a CD, or submitted in paper by mail or fax to ASHRAE, Manager of Standards, 1791 Tullie Circle, NE, Atlanta,GA 30329-2305. E-mail: [email protected]. Fax: +1-404/321-5478.

1. Submitter:

Affiliation:

Address: City: State: Zip: Country:

Telephone: Fax: E-Mail:

I hereby grant the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) the non-exclusive royalty rights, including non-exclusive rights in copyright, in my proposals. I understand that I acquire no rights in publication of the standard in which my proposals in this or other analogous form is used. I hereby attest that I have the author-ity and am empowered to grant this copyright release.

Submitter’s signature: _____________________________________________ Date: ____________________________

2. Number and year of standard:

3. Page number and clause (section), subclause, or paragraph number:

4. I propose to: [ ] Change to read as follows [ ] Delete and substitute as follows(check one) [ ] Add new text as follows [ ] Delete without substitution

Use underscores to show material to be added (added) and strike through material to be deleted (deleted). Use additional pages if needed.

5. Proposed change:

6. Reason and substantiation:

7. Will the proposed change increase the cost of engineering or construction? If yes, provide a brief explanation asto why the increase is justified.

[ ] Check if additional pages are attached. Number of additional pages: _______[ ] Check if attachments or referenced materials cited in this proposal accompany this proposed change. Please verify that allattachments and references are relevant, current, and clearly labeled to avoid processing and review delays. Please list yourattachments here:

Rev. 3-9-2007

All electronic submittals must have the following statement completed:

I (insert name) , through this electronic signature, hereby grant the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) the non-exclusive royalty rights, including non-exclusive rights in copyright, in my proposals. I understand that I acquire no rights in publication of the stan-dard in which my proposals in this or other analogous form is used. I hereby attest that I have the authority and am empow-ered to grant this copyright release.

POLICY STATEMENT DEFINING ASHRAE’S CONCERNFOR THE ENVIRONMENTAL IMPACT OF ITS ACTIVITIES

ASHRAE is concerned with the impact of its members’ activities on both the indoor and outdoor environment. ASHRAE’smembers will strive to minimize any possible deleterious effect on the indoor and outdoor environment of the systems andcomponents in their responsibility while maximizing the beneficial effects these systems provide, consistent with acceptedstandards and the practical state of the art.

ASHRAE’s short-range goal is to ensure that the systems and components within its scope do not impact the indoor andoutdoor environment to a greater extent than specified by the standards and guidelines as established by itself and otherresponsible bodies.

As an ongoing goal, ASHRAE will, through its Standards Committee and extensive technical committee structure,continue to generate up-to-date standards and guidelines where appropriate and adopt, recommend, and promote those newand revised standards developed by other responsible organizations.

Through its Handbook, appropriate chapters will contain up-to-date standards and design considerations as the material issystematically revised.

ASHRAE will take the lead with respect to dissemination of environmental information of its primary interest and will seekout and disseminate information from other responsible organizations that is pertinent, as guides to updating standards andguidelines.

The effects of the design and selection of equipment and systems will be considered within the scope of the system’sintended use and expected misuse. The disposal of hazardous materials, if any, will also be considered.

ASHRAE’s primary concern for environmental impact will be at the site where equipment within ASHRAE’s scopeoperates. However, energy source selection and the possible environmental impact due to the energy source and energytransportation will be considered where possible. Recommendations concerning energy source selection should be made byits members.

86501PC 08/4

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