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.
4 ANSI/ASHRAE/ASHE Standard 170-2008
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.
ANSI/ASHRAE/ASHE Standard 170-2008 5
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.
6 ANSI/ASHRAE/ASHE Standard 170-2008
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.
ANSI/ASHRAE/ASHE Standard 170-2008 7
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
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)
Pos
itiv
e4
20N
/RN
o30
–60
68–7
5/20
–24
Del
iver
y ro
om (
Cae
sare
an)
(m),
(n)
, (o)
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
8 ANSI/ASHRAE/ASHE Standard 170-2008
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
ANSI/ASHRAE/ASHE Standard 170-2008 9
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
10 ANSI/ASHRAE/ASHE Standard 170-2008
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
o w
aste
ane
sthe
tic g
ases
and
vap
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
aust
(sc
aven
ging
) 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
e al
arm
s. S
hort
term
exc
ursi
ons
from
req
uire
d pr
essu
re r
elat
ions
hips
sha
ll be
allo
wed
whi
le d
oors
are
mov
ing
orte
mpo
rari
ly o
pen.
Sim
ple
visu
al m
etho
ds s
uch
as s
mok
e tr
ail,
ball-
in-t
ube,
or
flut
ters
trip
sha
ll be
per
mitt
ed f
or v
erif
icat
ion
of a
irfl
ow d
irec
tion.
Rec
ircu
latin
g de
vice
s w
ith H
EPA
filt
ers
shal
l be
per-
mitt
ed i
n ex
istin
g fa
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
or f
ixed
sys
tem
s sh
ould
prev
ent s
tagn
atio
n an
d sh
ort c
ircu
iting
of
airf
low
. The
des
ign
of s
uch
syst
ems
shal
l als
o al
low
for
eas
y ac
cess
for
sch
edul
ed p
reve
ntat
ive
mai
nten
ance
and
cle
anin
g.o.
Surg
eons
or
surg
ical
pro
cedu
res
may
req
uire
roo
m te
mpe
ratu
res,
ven
tilat
ion
rate
s, h
umid
ity r
ange
s, a
nd/o
r ai
r di
stri
butio
n m
etho
ds th
at e
xcee
d th
e m
inim
um in
dica
ted
rang
es.
p.T
reat
men
t roo
ms
used
for
bron
chos
copy
sha
ll be
trea
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
exha
ustin
g an
esth
etic
was
te g
ases
.q.
In a
rec
ircu
latin
g ve
ntila
tion
syst
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
the
outd
oors
pro
vide
d th
e re
turn
air
pas
ses
thro
ugh
the
HE
PA fi
lter
s be
fore
it is
intr
oduc
ed in
to a
ny o
ther
spa
ces.
Thi
s re
quir
emen
t app
lies
only
to w
aitin
g ro
oms
prog
ram
med
to h
old
patie
nts
awai
ting
ches
t x-r
ays
for
diag
nosi
s of
res
pira
tory
dis
ease
.r.
See
NF
PA 9
9 fo
r fu
rthe
r re
quir
emen
ts.8
s.Fo
r pa
tient
roo
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).
Rec
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.
Con
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
ANSI/ASHRAE/ASHE Standard 170-2008 11
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.
12 ANSI/ASHRAE/ASHE Standard 170-2008
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.
ANSI/ASHRAE/ASHE Standard 170-2008 13
(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.
14 ANSI/ASHRAE/ASHE Standard 170-2008
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].
ANSI/ASHRAE/ASHE Standard 170-2008 15
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.
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