1 February 1999
Consider both unit heaters and radiant heaters as alternatives in the life cycle cost analysis.
Evaporative cooling may be provided in active warehouses where effective.
b. Dehumidified Warehouse.
(1) Where only humidity control is required, the life cycle cost analysis will compare
dry desiccant-type dehumidifier and refrigerated dehumidification. The dry desiccant type will
consist of two stationary beds or will be the rotary type with operation alternating between drying
(2) Where both temperature and humidity control are required, use a central air
a. Design HVAC systems to provide control over space temperature conditions including
contaminants and fume control appropriate to the space function. Provide exhaust systems with
fume hoods to remove toxic substances as near to the source of the fumes as practical. Hood
and system design will follow the recommendations of the American Conference of Government
Industrial Hygienists Manual. Base minimum design face velocities for hoods on the toxicity of
the material being handled. Face velocities at the hood opening should be as follows: highly
toxic substances at 0.65 m/s (125 fpm), general laboratory exhaust at 0.45 m/s (80 fpm), and
non-toxic substances at .025 m/s (5 fpm).
b. Base the amount of supply air on the room-cooling load and all exhaust requirements.
Design air supply, exhaust and automatic control systems to provide flexibility for potential
changes in the use of space.
4-15. HOSPITALS. HVAC designs for hospitals will be in accordance with Military Handbook
4-16. COMMISSARIES. HVAC designs for commissaries will be in accordance with the AEI.
4-17. LAUNDRIES AND DRY CLEANERS. Mechanical ventilation will generally be the primary
method of heat dissipation. Evaporative cooling may be provided where effective. Spot air
conditioning or general air conditioning may be provided to keep the temperature in the work
areas from exceeding 29 degrees C (85 degrees F). Coil discharge temperatures used in spot
cooling should be 10 degrees C (50 degrees F) dry bulb maximum for maximum
dehumidification. Where feasible, use heat recovery equipment on exhaust air to temper
makeup air in cold weather. Design clothes dryer exhaust venting in accordance with ETL
1110-3-483, Clothes Dryer Exhaust Venting.
4-18. RESERVE CENTERS. Typically, only a small portion of a reserve center is occupied
during normal working hours, while the balance of the facility is used primarily for weekends
only. Consider the anticipated occupancy pattern when developing equipment layout and
sequence of operation in order to ensure that overall life cycle cost is minimized.