Mechanical ventilation for health care facilities shall be designed and installed in accordance with this code and ASHRAE 170 [OSHPD 1, 1R, 2, 3, 4 & 5]-2013, through Addendum ae, as published with "Guidelines for Design and Construction of Hospitals and Outpatient Facilities," 2014 edition (published by The Facility Guidelines Institute). All supply-ail; return air, and exhaust-air systems shall comply with ASHRAE 170. The text of ASHRAE 170 shall be modified as follows:
Note: NR = No requirement
Notes for Table 4-A:
- ASHRAE 170. Section 220.127.116.11 -- Not adopted.
- ASHRAE 170. Section 6.3.2 -- Not adopted.
- ASHRAE 170. Table 6.4 -- Not adopted.
- ASHRAE 170. Section 6.4-6.4.4 -- Not adopted.
- ASHRAE 170. Section 6.9 -- Not adopted.
- ASHRAE 170. Section 7.1a -- Modify as follows:
Replace reference to Table 7.1 with reference to Table 4-A.
- ASHRAE 170. Section 7.2.1a through e -- Not adopted.
- ASHRAE 170. Section 7.2.2 a through c, and e -- Not adopted.
- ASHRAE 170. Section 7.2.3 -- Not adopted.
- ASHRAE 170. Section 7.3.1 -- Modify as follows:
Replace reference to Table 7.1 with reference to Table 4-A.
- ASHRAE 170. Section 7.4.1 -- Modify as follows:
Delete the Exception that allows for high return grilles.
|FUNCTION OR SPACE||PRESSURE RELATION-SHIP TO ADJACENT AREAS (f) (n)||MINIMUM OUTDOOR ACH||MINIMUM TOTAL ACH||MINIMUM TOTAL ACH IF 100% O.A.||ALL ROOM AIR EXHAUSTED DIRECTLY TO OUTDOORS (j)||AIR RECIRCULATED BY MEANS OF ROOM UNITS (a)||DESIGN RELATIVE HUMIDITY(k), %||DESIGN TEMPERATURE (l),° F/°C|
|Airborne infection isolation anteroom (u)||(e)||NR||10||10||Yes||No||NR||NR|
|Airborne infection isolation room (u)||Negative||2||12||12||Yes||No||max 60||70-75/21-24|
|Airborne infection isolation treatment/exam room||Negative||2||12||12||Yes||No||NR||NR|
|Blood bank/tissue storage||NR||2||6||6||NR||NR||NR||NR|
|Bronchoscopy, sputum collection, and pentamidine administration (n)||Negative||2||12||12||Yes||No||NR||68-73/20-23|
|Cardiac catheterization lab||Positive||5||20||12||NR||No||max 60||70-75/21-24|
|Clean linen storage||Positive||NR||2||2||NR||NR||NR||72-78/22-26|
|Clean workroom (central medical and surgical supply space)||Positive||2||4||4||NR||No||max 60||72-78/22-26|
|Clean workroom or clean holding (support)||Positive||2||4||4||NR||NR||NR||NR|
|Critical and intensive care||NR||2||6||6||NR||No||30-60||70-75/21-24|
|CT Scan||NR||2||6||6||NR||NR||max 60||NR|
|Delivery room (cacsar can) (m), (n), (o)||Positive||4||20||12||NR||No||20-60||68-75/20-24|
|Dialysis treatment area||NR||2||6||6||NR||NR||NR||72-78/22-26|
|Dialyzer reprocessing room||Negative||NR||10||NR||Yes||No||NR||NR|
|Electroconvulsive therapy procedure room||P||3||15||10||NR||NR||NR||NR|
|Emergency department exam/treatment room (p)||NR||2||6||6||NR||NR||max 60||70-75/21-24|
|ER waiting rooms||Negative||2||12||12||Yes (q)||NR||max 65||70-75/21-24|
|Examination room||NR||2||6||6||NR||NR||max 60||70-75/21-24|
|Fast track room||NR||2||6||2||NR||NR||NR||NR|
|Food preparation center (i)||NR||2||10||10||NR||No||NR||72-78/22-26|
|Gastrointestinal endoscopy procedure room (x)||NR||2||6||12||NR||No||20-60||68-73/20-23|
|Hazardous material storage||Negative||2||10||10||Yes||No||NR||NR|
|Intermediate care (s)||NR||2||6||6||NR||NR||max 60||70-75/21-24|
|Interventional imaging procedure room||Positive||5||15||12||NR||NR||NR||NR|
|IV Prep. room||Positive||2||6||6||NR||NR||NR||NR|
|Janitor's closet, housekeeping||Negative||NR||10||10||Yes||No||NR||NR|
|Labor/delivery/recover (LDR) (s)||NR||2||6||2||NR||NR||max 60||70-75/21-24|
|Labor/delivery/recovery/ postpartum (LDRP) (s)||NR||2||6||2||NR||NR||max 60||70-75/21-24|
|Laboratory, bacteriology (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, biochemistry (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, cytology (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, general (v)||Negative||2||6||6||NR||NR||NR||70-75/21-24|
|Laboratory, histology (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, infectious disease and virus||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, media transfer (v)||Positive||2||4||4||NR||NR||NR||70-75/21-24|
|Laboratory, microbiology (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, nuclear medicine (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, pathology (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laboratory, serology (v)||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Laser eye room||Positive||3||15||15||NR||No||20-60||70-75/21-24|
|Linen and trash chute room||Negative||NR||10||10||Yes||No||NR||NR|
|Medical/anesthesia gas storage (r)||Negative||NR||8||8||Yes||NR||NR||NR|
|Medication room||NR||2||4||2||NR||NR||max 60||70-75/21-24|
|Morgues and autopsy room (n)||Negative||2||12||12||Yes||No||NR||68-75/20-24|
|Negative-pressure x-ray room||Negative||2||12||12||Yes||No||max 60||72-78/22-26|
|Newborn intensive care||Positive||2||6||6||NR||No||30-60||72-78/22-26|
|Newborn intensive care formula room||P||2||10||10||NR||No||NR||NR|
|Newborn/well baby nursery suite||NR||2||6||6||NR||No||30-60||72-78/22-26|
|Nonrefrigerated body-holding room (h)||Negative||NR||10||10||Yes||No||NR||70-75/21-24|
|Nourishment area or room||NR||NR||2||2||NR||NR||NR||NR|
|Nuclear medicine (Gamma, PET, SPECT)||Negative||2||6||6||Yes||No||NR||NR|
|Nuclear medicine hot lab||Negative||NR||6||6||Yes||No||NR||70-75/21-24|
|Nuclear medicine treatment room||Negative||2||6||6||Yes||NR||NR||70-75/21-24|
|Nurse station (aa)||(aa)||(aa)||2||2||(aa)||(aa)||(aa)||(aa)|
|Operating room, hybrid operating room (m), (n), (o)||Positive||4||20||12||NR||No||20-60||68-75/20-24|
|Operating/surgical cystoscopic room (m), (n), (o)||Positive||4||20||12||NR||No||20-60||68-75/20-24|
|Patient holding preparation||NR||2||6||6||NR||No||NR||NR|
|Patient room||NR||2||4 (y)||2||NR||NR||max 60||70-75/21-24|
|Pediatric play area||NR||2||6||6||NR||NR||NR||NR|
|HD ante room (b)||Positive||NR||NR||NR||NR||NR||<60||≤68/≤20|
|HD buffer room (b)||Negative||NR||30||30||Yes||No||<60||≤68/≤20|
|HD segregated compounding area (b)||Negative||NR||12||12||Yes||NR||NR||NR|
|HD storage (b)||Negative||NR||12||12||Yes||NR||NR||NR|
|Non-HD ante room (b)||Positive||NR||30||30||NR||NR||<60||≤68/≤20|
|Non-HD buffer room (b)||Positive||NR||30||30||NR||No||<60||≤68/≤20|
|Non-HD segregated compounding area (b)||NR||NR||NR||NR||NR||NR||NR||NR|
|Physical therapy (nursing facility)||Negative||2||6||6||NR||NR||NR||70-75/21-24|
|Physical therapy (diagnostic and treatment)||Negative||2||6||6||NR||NR||max 65||72-80/22-27|
|Post-anesthesia care unit||NR||2||6||6||Yes||No||20-60||70-75/21-24|
|Pre-screening area||Negative||2||12||12||Yes (q)||NR||NR||NR|
|Procedure room (o), (d)||Positive||3||15||12||NR||No||20-60||70-75/21-24|
|Protective environment anteroom (t)||(e)||NR||10||15||NR||No||NR||NR|
|Protective environment room (t)||Positive||2||12||15||NR||No||max 60||70-75/21-24|
|Radiology waiting rooms||Negative||2||12||12||Yes (q), (w)||NR||max 60||70-75/21-24|
gathering/activity/dining (nursing facility)
|Resident room (nursing facility)||NR||2||2||2||NR||NR||NR||70-75/21-24|
|Resident unit corridor (nursing facility)||NR||NR||4||2||NR||NR||NR||NR|
|Soiled linen sorting and storage||Negative||NR||10||10||Yes||No||NR||NR|
|Soiled or decontamination room||Negative||2||6||4||Yes||No||NR||72-78/22-26|
|Soiled workroom or soiled holding, utility room||Negative||2||10||4||Yes||No||NR||NR|
|Special purpose room (SNF & ICF only)||NR||2||6||6||Yes||NR||NR||NR|
|Speech therapy/audiology room||NR||2||6||2||NR||NR||NR||NR|
|Sterile storage||Positive||2||4||4||NR||NR||max 60||72-78/22-26|
|Sterilizer equipment room||Negative||NR||10||10||Yes||No||NR||NR|
|Substerile service area||NR||2||6||6||NR||No||NR||NR|
|Trauma/cardiac room (crisis or shock) (c)||Positive||3||15||12||NR||No||20-60||70-75/21-24|
|Treatment room (surgery and critical care) (p)||NR||2||6||6||NR||NR||20-60||70-75/21-24|
|Treatment room (diagnostic
and treatment) (x)
|Triage||Negative||2||12||12||Yes (q)||NR||max 60||70-75/21-24|
|Waiting area (nuclear medicine)||Negative||2||12||12||Yes||No||NR||NR|
|Waiting area primary care clinic||Negative||2||10||10||Yes(q)||NR||NR||NR|
|Wound intensive care (burn unit)||NR||2||6||6||NR||No||40-60||70-75/21-24|
|X-ray (diagnostic and treatment)||NR||2||6||6||NR||NR||max 60||72-78/22-26|
|X-ray (surgery/critical care and catheterization)||Positive||3||15||12||NR||No||max 60||70-75/21-24|
Notes for Table 4-A:
- Except where indicated by a "No" in this column, recirculating room HVAC units (with heating or cooling coils) are acceptable for providing that portion of the minimum total air changes per hour that is permitted by Section 7.1 (subparagraph [a]). Because of the cleaning difficulty and potential for buildup of contamination, recirculating room units shall not be used in areas marked "No." Recirculating devices with HEPA filters shall be permitted in existing facilities as interim, supplemental environmental controls to meet requirements for the control of airborne infectious agents. The design of either portable or fixed systems should prevent stagnation and short circuiting of airflow. The design of such systems shall also allow for easy access for scheduled preventative maintenance and cleaning.
- Additional air change, ISO class. differential pressure, continuous pressure monitoring and filtering requirements for compounding areas shall comply with California Board of Pharmacy regulations Title 16 § 1735 & §1751, and USP<797> & <800>. Air supplied to the cleanroom suite must be introduced through 99.9 7% minimum HEPA filters located in the ceiling. At least 15 air changes per hour (ACPH) shall be provided to nonhazardous drug (non-HD) compounding buffer rooms through the ceiling. The HEPA filtered air from the PEC in the non-HD buffer room. when added to the HVAC-supplied HEPA filtered air. shall increase the total HEPA-filtered ACPH to at least 30 If the PEC is used to meet the minimum total ACPH requirements, the PEC must not be turned off except for maintenance. All hazardous drug (HD) compounding areas and PE Cs shall be exhausted externally through 99.97% HEPA filtration. Minimum air changes shall be met under operating conditions. Returns and exhaust grilles shall be mounted low on the wall unless a visual smoke study demonstrates dilution of particles and sweeping out of particles from the entire room. One return/exhaust should be placed near the refrigerator compressor.
- The term trauma room as used herein is a first-aid room and/or emergency room used for general initial treatment of accident victims. The operating room within the trauma center that is routinely used for emergency surgery is considered to be an operating room by this standard.
- Pressure relationships need not be maintained when the room is unoccupied.
- See Section 7.2 of ASHRAE 170 and its subsections for pressure-relationship requirements.
- For operating rooms, cardiac catheterization labs, angiography rooms, cystoscopy rooms. delivery rooms. cesarean operating rooms, newborn intensive care, intensive care units, and nurseries provide approximately 15% excess supply air to the room or a sufficient quantity of excess supply air to maintain an appropriate positive air balance based on the room tightness and number of doors. For all rooms not listed in this footnote or not listed in Section 322.0 requiring either a positive or negative air balance, provide approximately 10% differential cfm between supply and return/exhaust airflow but not less than 25 cfm differential shall be provided regardless of room size. Room function, size, and tightness may be considered when determining the differential airflow required. Where continuous directional control is not required, variations between supply cfm and return or exhaust cfm shall be minimized.
- All air need not be exhausted if darkroom equipment has a scavenging exhaust duct attached and meets ventilation standards regarding NIOSH, OSHA, and local employee exposure limits.2, 3
- A nonrefrigerated body-holding room is applicable only to facilities that do not perform autopsies on-site and use the space for short periods while waiting for the body to be transferred.
- Minimum total air changes per hour (ach) shall be that required to provide proper makeup air to kitchen exhaust systems as specified in ANSI/ASHRAE Standard 154.4 In some cases, excess exfiltration or infiltration to or from exit corridors compromises the exit corridor restrictions of NFPA 90A,5 the pressure requirements of NFPA 96,6 or the maximum defined in the table. During operation, a reduction to the number of air changes to any extent required for odor control shall be permitted when the space is not in use. (See FGI  in Informative Appendix B.)
- In some areas with potential contamination and/or odor problems, exhaust air shall be discharged directly to the outdoors and not recirculated to other areas. Individual circumstances, nay require special consideration for air exhausted to the outdoors. To satisfy exhaust needs, constant replacement air from the outdoors is necessary when the system is in operation.
- The RH ranges listed are the minimum and/or maximum allowable at any point within the design temperature range required for that space.
- Systems shall be capable of maintaining the rooms within the range during normal operation. Lower or higher temperature shall be permitted when patients' comfort and/or medical conditions require those conditions.
- National Institute for Occupational Safety and Health (NIOSH) criteria documents regarding occupational exposure to waste anesthetic gases and vapors, and control of occupational exposure to nitrous oxide7 indicate a need for both local exhaust (scavenging) systems and general ventilation of the areas in which the respective gases are utilized. Refer to NFPA 99 for other requirements.8
- If pressure-monitoring device alarms are installed, allowances shall be made to prevent nuisance alarms. Short-term excursions from required pressure relationships shall be allowed while doors are moving or temporarily open. Simple visual methods such as smoke trail, ball-in-tube, or flutterstrip shall be permitted for verification of airflow direction.
- Surgeons or surgical procedures may require room temperatures, ventilation rates, humidity ranges, and/or air distribution methods that exceed the minimum indicated ranges.
- Treatment rooms used for bronchoscopy shall be treated as bronchoscopy rooms. Treatment rooms used for procedures with nitrous oxide shall contain provisions for exhausting anesthetic waste gases.
- In a recirculating ventilation system, HEPA filters shall be permitted instead of exhausting the air from these spaces to the outdoors provided that the return air passes through the HEPA filters before it is introduced into any other spaces. The entire minimum total air changes per hour of recirculating airflow shall pass through HEPA filters. when these areas are open to larger, nonwaiting spaces, the exhaust air volume shall be calculated based on the seating area of the waiting area. (Note: The intent here is to not require the volume calculation to include a very large space [e.g., an atrium] just because a waiting area opens onto it.)
- See NFPA 99 for further requirements. 8
- For intermediate care, labor/delivery/recovery rooms, and labor/delivery/recovery/postpartum rooms, four total ach shall be permitted when supplemental heating and/or cooling systems (radiant heating and cooling, baseboard heating, etc.) are used.
- The protective environment airflow design specifications protect the patient from common environmental airborne infectious microbes (i.e., Aspergillus spores). The anteroom shall have negative air pressure in relation to the protective environment room. A door louver, transfer grille, or other acceptable means may be provided to allow for airflow from the protective environment room to the anteroom. The protective environment room shall have positive-pressure in relation to the anteroom and adjoining toilet room. Recirculation HEPA filters shall be permitted to increase the equivalent room air exchanges; however, the outdoor air changes are still required. Constant-volume airflow is required for consistent ventilation for the protected environment. The pressure relationship to adjacent areas shall remain unchanged if the PE room is utilized as a normal patient room. Rooms with reversible airflow provisions for the purpose of switching between protective environment and All functions shall not be permitted.
- The All room described in this standard shall be used for isolating the airborne spread of infectious diseases, such as measles, varicella, or tuberculosis. The airborne infection isolation room shall have negative pressure in relation to the anteroom, and the adjoining toilet room shall have negative pressure in relation to the airborne infection isolation room. Supplemental recirculating devices using HEPA filters shall be permitted in the All room to increase the equivalent room air exchanges; however, the minimum outdoor air changes of Table 4-A are still required. All rooms that are retrofitted from standard patient rooms from which it is impractical to exhaust directly outdoors may be recirculated with air from the All room, provided that air first passes through a HEPA filter. When the All room is not utilized for airborne infection isolation, the pressure relationship to adjacent areas, when measured with the door closed, shall remain unchanged and the minimum total air change rate shall be 6 ach. Switching controls for reversible airflow provisions shall not be permitted. The anteroom shall have positive air pressure in relation to the airborne infection isolation room. A door louver, transfer grille, or other acceptable means may be provided to allow for airflow from the anteroom to the airborne infection isolation room.
- When required, appropriate hoods and exhaust devices for the removal of noxious gases or chemical vapors shall be provided in accordance with NFPA 99.8
- The requirement that all room air is exhausted directly to outdoors applies only to radiology waiting rooms programmed to hold patients who are waiting for chest x-rays for diagnosis of respiratory disease.
- If the planned space is designated in the organization's operational plan to be utilized for both bronchoscopy and gastrointestinal endoscopy, the design parameters for "bronchoscopy, sputum collection, and pentamidine administration" shall be used.
- For single-bed patient rooms using Group D diffusers, a minimum of six total ach shall be provided and calculated based on the volume from finished floor to 6 ft (1.83 m) above the floor.
- This table is based on Table 7.1 in ASHRAE 170, "Ventilation of Healthcare Facilities", and is used with expressed written permission from ASHRAE.
- Nurse station pressure relationship and ventilation requirements shall match the area in which it is located.
- Air change per hour and ventilation rates for spaces not listed in Table 4-A may be per ASHRAE 62.1.