15 May 2003
General Purpose Aircraft Hangars. Select heating systems
on the basis
the outdoor design temperatures as presented in table 4-1. Floor-type unit heaters will
introduce 20 percent outside air. Direct the discharged air to cover the entire floor area
to break up explosive pockets. Provide motor-operated fresh air dampers for 100
percent outside air when desired. The capacity of heater fans will provide not less than
six air changes per hour based on an artificial ceiling height of 15 feet (5 meters). In
alert hangers, provide mechanical exhaust ventilation consisting of not less than 30 air
changes per hour for control. In climates with winter design temperatures below 10
degrees F (-12 degrees C) or where annual snowfall exceeds 20 inches (50 cm),
provide snow-melting coils circulating heated antifreeze solution under hangar door
Table 4-1. Heating System - Hangars
Outside Design Temperature
Radiant heating will be installed in the
0 degrees F (-18 degrees C) and below
floor slab of the hangar area to provide
50% of the requirement, supplemented
by floor-type air-handling units.
Between 1 degrees F and 40 degrees F
Floor-type air-handling units will be
provided. Overhead and unfired unit
(-17 degrees C and 4 degrees C).
heaters may be used to supplement floor-
type heaters where hangar width is
greater than 150 ft (45 meters).
Above 40 degrees F (4 degrees C).
Note: Floor-type air-handling units will be arranged to draw warm air from the top of the
hangar for distribution at occupied level.
Aircraft Maintenance Shops (Avionics). Where effective, evaporative
cooling may be used. Provide air conditioning for those functional areas where required
for quality control of equipment, material, and task. In all cases, localized or spot air
conditioning may be provided at individual workstations; however, the entire shop area
will not be air conditioned.
General Purpose Warehouses. Do not heat warehouses used to store
materials not subject to freezing. For warehouses containing materials subject to
freezing, design heating systems to maintain an inside winter temperature of 40
degrees F (4 degrees C). In warehouse areas with active employment, temperatures of
55 degrees F (13 degrees C) will be maintained.