1  Sound transmission class (STC) shall be determined by tests in accordance with methods set forth in ASTM Standard E90 and ASTM E413. Where partitions do not extend to the structure above, sound transmission through ceilings and composite STC performance shall be considered.

2  Public space includes corridors (except patient room access corridors), lobbies, dining rooms, recreation rooms, and similar spaces.

3  Service areas include kitchens, elevators, elevator machine rooms, laundries, and similar spaces garages, maintenance rooms, boiler and mechanical equipment rooms, and similar spaces of high noise. Mechanical equipment located on the same floor or above patient rooms, offices, nurses stations, and similar occupied space shall be effectively isolated from the floor.

4  Patient room access corridors contain composite walls with doors/windows and have direct access to patient.

1  Note: Where temperature ranges are indicated, the systems shall be capable of maintaining the rooms at any point within the range. A single figure indicates a heating or cooling capacity of at least the indicated temperature. This is usually applicable when patients may be undressed and require a warmer environment. Nothing in these guidelines shall be construed as precluding the use of temperatures lower than those noted when the patients' comfort and medical conditions make lower temperatures desirable. Unoccupied areas such as storage rooms shall have temperatures appropriate for the function intended.

2  Footnote not supplied in original.

1  The ventilation rates in this table cover ventilation for comfort, as well as for asepsis and odor control in areas that directly affect patient care and are determined based on healthcare facilities being predominantly “No Smoking” facilities. Where smoking may be allowed, ventilation rates will need adjustment. Areas where specific ventilation rates are not given in the table shall be ventilated in accordance with ASHRAE Standard 62, Ventilation for Acceptable Indoor Air Quality; and ASHRAE Handbook-HVAC Applications. OSHA standards and/or NI0SH criteria require special ventilation requirements for employee health and safety within healthcare facilities.

2  Design of the ventilation system shall provide air movement which is generally from clean to less clean areas. If any form of variable air volume or load shedding system is used for energy conservation, it shall not 2 

3  Compromise the corridor-to-room pressure balancing relationships or the minimum air changes required by the table.

4  To satisfy exhaust needs, replacement air from the outside is necessary. Table 4 does not attempt to describe specific amounts of outside air to be supplied to individual spaces except for certain areas such as those listed. Distribution of the outside air, added to the system to balance required exhaust, shall be as required by good engineering practice. Minimum outside air quantities shall remain constant while the system is in operation.

5  Number of air changes may be reduced when the room is unoccupied if provisions are made to ensure that the number of air changes indicated is reestablished any time the space is being utilized. Adjustments shall include provisions so that the direction of air movement shall remain the same when the number of air changes is reduced. Areas not indicated as having continuous directional control may have ventilation systems shut down when space Is unoccupied and ventilation is not otherwise needed, if the maximum infiltration or exfiltration permitted in Note 2 is not exceeded and if adjacent pressure balancing relationships are not compromised. Air quantity calculations shall account for filter loading such that the indicated air change rates are provided up until the time of filter change-out.

6  Air change requirements indicated are minimum values. Higher values should be used when required to maintain indicated room conditions (temperature and humidity), based on the cooling load of the space (lights, equipment, people, exterior walls and windows, etc.).

7  Air from areas with contamination and/or odor problems shall be exhausted to the outside and not recirculated to other areas.

8  Recirculating room HVAC units refers to those local units that are used primarily for heating and cooling of air, and not disinfection of air. Because of cleaning difficulty and potential for buildup of contamination, recirculating room units shall not be used in areas marked “No.” However, for airborne infection control, air may be recirculated within Individual isolation rooms if HEPA filters are used. Isolation rooms may be ventilated by reheat induction units in which only the primary air supplied from a central system passes through the reheat unit.

9  Differential pressure shall be a minimum of 0.01″ water gauge (2.5 Pa). If alarms are installed, allowances shall be made to prevent nuisance alarms of monitoring devices.

10  Total air changes per room for patient rooms may be reduced to 4 when supplemental heating and/or cooling systems (radiant heating and cooling, baseboard heating, etc.) are used.

11  The protective environment airflow design specifications protect the patient from common environmental airborne infectious microbes (i.e., Aspergillus spores). These special ventilation areas shall be designed to provide directed airflow from the cleanest patient care area to less clean areas. These rooms shall be protected with HEPA filters at 99.97 percent efficiency for a 0.3 micron sized particle in the supply airstream. These Interrupting filters protect patient rooms from maintenance-derived release of environmental microbes from the ventilation system components. Recirculation HEPA filters can be used to increase the equivalent room air exchanges. Constant volume airflow is required for consistent ventilation for the protected environment. It the facility determines that airborne infection isolation is necessary for protective environment patients, an anteroom shall be provided. Rooms with reversible airflow provisions for the purpose of switching between protective environment and airborne infection isolation functions are not acceptable.

12  The infectious disease isolation room described in these guidelines is to be used for isolating the airborne spread of infectious diseases, such as measles, varicella, or tuberculosis. The design of airborne infection isolation (All) rooms should include the provision for normal patient care during periods not requiring Isolation precautions. Supplemental recirculating devices may be used in the patient room, to increase the equivalent room air exchanges; however, such recirculating devices do not provide the outside air requirements. Air may be recirculated within individual isolation rooms if HEPA filters are used. Rooms with reversible airflow provisions for the purpose of switching between protective environment and All functions are not acceptable.