Ventilation. Refer to MIL-HDBK-1012/1, NAVFAC DM-3.03, and
in accordance with the following:
a) Provide outside air ventilation requirements in accordance with
ASHRAE Standard 62, Ventilation for Acceptable Indoor Air Quality and
b) Ensure restroom facilities are exhausted at a minimum of 2
cfm/square feet and not less than 25 cfm total. Provide exhaust fans which
operate when restroom is occupied. Interlock exhaust fan with light switch
c) Do not provide exhaust fans for the ventilation of electronic
equipment rooms. Accomplish ventilation through the use of thermostatically
controlled intake fans providing a filtered air supply to the equipment room.
Maintain positive air pressure in electronic equipment rooms to reduce the
infiltration of dust and other foreign matter through door jambs and other
openings. Consider high efficiency (60 to 90 percent) filtration where dust
and other particulate/pollution can cause malfunctioning of equipment. When
intake air is from a salt-laden environment, route intake air through the
dehumidifying system to remove moisture suspended salts.
d) Ventilate uninterrupted power supply (UPS) rooms in accordance
Battery Shops. Provide recessed air supply and exhaust vents in the
ceiling of lead acid and nickel-cadmium battery shops. Slope the ceiling
surface to provide a single high point at the exterior wall of the building.
Locate the exhaust vent at the highest ceiling point and discharge the exhaust
through the exterior wall. Do not recess other items in the battery shop
ceilings. Design battery shop ventilation systems in accordance NFPA 70,
National Electrical Code and the following:
a) Provide one air change per hour for nickel-cadmium battery
shops. Increase the air change rate when outdoor air can be used to limit the
shop temperature to 85 degrees F.
b) Provide three air changes per hour for lead acid battery shops.
Increase the air change rate when required for mechanical ventilation cooling.
Provide a non-sparking wheel and locate the fan motor out of the air stream.
Design the ventilation system to provide negative static pressure by
exhausting 10 percent more air than supplied. Provide 100 percent outside air
Outside Weather Conditions. Obtain summer and winter outside
weather conditions from NAVFAC P-89, Engineering Weather Data, or ASHRAE
Handbook of Fundamentals.