TM 9-4120-399-14
Section IV. OPERATION UNDER UNUSUAL CONDITIONS
2-15. GENERAL. The air conditioner is designed to operate normally within a wide range of
climatic conditions. However, some extreme conditions require special operating and servicing
procedures to prevent undue loading and excessive wear on the equipment. These unusual
conditions and the special steps to be performed are listed in the following paragraphs.
125F (52C) or higher, extra care should be taken to minimize the cooling load. Some of the
precautions that may be taken are:
a. Check all openings in the shelter or enclosure, especially doors and windows, to be sure
they are tightly closed. Limit in and out traffic, if possible.
b. When possible, use shades or awnings to shut out direct rays of the sun.
c. Limit the use of electric lights and other heat producing equipment.
d. Limit the amount of hot, outside air introduced through the fresh air damper to that
needed for ventilation.
NOTE
Weather stripping, the installation of storm doors and windows (if
a p p r o p r i a t e ) , and insulation of surfaces exposed to the outside is
recommended when operation in extremely high temperatures for extended
periods is anticipated.
down to -50F (-45'C), extra care should be taken to minimize the heating load. Some of the
steps that may be taken are:
CAUTION
Do not disturb electrical wiring that has been exposed to extremely low
temperatures. When exposed to cold, both the wire and insulation become
brittle and can be easily broken.
a. Check all openings in the enclosure, especially doors and windows, to be sure they are
tightly closed. Limit in and out traffic, if possible.
b. Open shades and awnings to permit entry of direct rays of the sun, if appropriate.
c. Limit the amount of cold, outside air introduced through the fresh air damper to that
needed for ventilation.
