Section IV. OPERATION UNDER UNUSUAL CONDITIONS

TM5-4120-347-14

Section IV.

OPERATION UNDER UNUSUAL

CONDITIONS

The Model F9000H-3 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.

2-11. OPERATION IN EXTREME HEAT

The air conditioner is designed to operate in temperatures up to 120F (40C). 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. 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 essential for

ventilation.

NOTE

Weatherstripping, 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 is anticipated.

e. Clean filter, mist eliminator and coils more frequently.

2-12. OPERATION IN EXTREME COLD

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 -50F (-45C) and in the

COOL mode at outside temperatures down to 0F (-18C). 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.

c. Limit the amount of cold, outside air introduced through the fresh air damper to that essential for

ventilation.