TM 9-4120-385-14
Section III. OPERATION UNDER USUAL CONDITIONS
WARNING
Recirculation of stale air can use up existing shelter oxygen
supplies resulting in dizziness, nausea, headache, and
unconsciousness. Make sure to introduce about 10% fresh
air into the system to allow for adequate ventilation.
CAUTION
The shelter or van circuit breaker and CB (providing power to the
air conditioner) should be ON at least 6 hours before operating the
unit in the COOL mode. This allows the crankcase heater to raise
the compressor oil temperature to normal operating range.
NOTE
Cool air is denser than warm air, and it tends to sink downward,
therefore, it is usually desirable to direct cool air slightly upward
and warm air slightly downward for maximum comfort and
coverage.