TM 9-4120-388-14
Section IV. OPERATION UNDER UNUSUAL CONDITIONS
2-15. GENERAL. The 18,000 BTU/HR 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 load-
ing and excessive wear on the equipment.
2-16. OPERATION IN EXTREME HEAT.
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 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
Weatherstripping, the installation of storm doors and windows (if appropriate), and in-
sulation of surfaces exposed to the outside is recommended when operating in extreme-
ly high temperatures for extended periods.
Cleaning
c.
Clean outside grilles, coil, filters, and mist eliminator more frequently.
2-17. OPERATION IN EXTREME COLD.
Do not disturb electrical wiring that has been exposed to extremely low tempera-
tures. Both the wire and insulation become brittle when cold and are easily bro-
ken.
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:
Be sure all openings in the shelter or enclosure, especially doors and windows, are tightly closed. Limit in and
a.
out traffic, if possible.
b.
Open shades or awnings to permit entry of direct rays of the sun if appropriate.
Limit the amount of cold, outside air introduced through the fresh air damper to that needed for ventilation.
c.
NOTE
Weatherstripping, the installation of storm doors and windows (if appropriate), and in-
sulation of surfaces exposed to the outside is recommended when operating in extreme-
ly low temperatures for extended periods.