TM 9-4120-402-14
Section IV OPERATION UNDER UNUSUAL CONDITIONS
2-14.
GENERAL.
The Model F18T-M PI 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.
2-15.
OPERATION IN EXTREME HEAT.
The air conditioner is designed to operate in temperatures up to 120OF (490C). Extra care should be taken to minimize
the cooling load when operating in extremely high 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. When appropriate, use shades or awnings to shut out direct rays of the sun.
c.
When possible, 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 essential for ventilation.
e. Clean filter, mist eliminator, and coils more frequently.
2-16.
OPERATION IN EXTREME COLD.
CAUTION
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 the HEAT mode at temperatures down to -50 (-45 ) and in the COOL
F
C
mode at outside temperatures down to 45 (70 ). Extra care should be taken to minimize the heating load when
F
C
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.
c.
Limit the amount of cold, outside air introduced through the fresh air damper to that essential for ventilation.
2-22
