TM 9-4120-371-14
S e c t i o n 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 wear on
the equipment.
NOTE
Unit Preventive Maintenance Checks and Services (PMCS) should be performed at
daily intervals.
a. General. The air conditioner is designed to operate in temperatures up to 120F (49C). Extra care
should be taken to minimize the cooling load when operating in extremely high temperatures.
b. Protection.
(1) Check all openings in the or enclosure, especially doors and windows, to be sure they are tightly
closed. Limit in and out traffic, if possible.
(2) When appropriate, use shades or awnings to shut out direct rays of the sun.
(3) When possible, limit the use of electric lights and other heat producing equipment.
(4) Limit the amount of hot, outside air introduced through the fresh air damper to that essential for
ventilation.
NOTE
Weather stripping, the installation of storm doors and windows, if appropriate, and
insulation of surfaces exposed to the outside is recommended when operating in
extremely high temperatures for extended periods.
c. Cleaning.
(1) Clean outside grilles, coils, filters, and mist eliminator more frquently.
Do not disturb electrical wiring that has been exposed to extremely low temperatures.
Both the wire and insulation become brittle when cold and are easily broken.
The air conditioner is designed to operate in temperatures down to 50F (45C). Extra care should be taken to
minimize the heating load when operating in extremely low temperatures. Some of the steps that may be taken
are:
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.