TM 9-4120-371-14
c. Limit the amount of cold, outside air introduced through the fresh air damper to that needed 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 operation at
extremely low temperatures for extended periods is anticipated.
NOTE
Unit Preventive Maintenance Checks and Services (PMCS) should be performed at
daily intervals.
a. General. Dusty and sandy conditions can seriously reduce the efficiency of the air conditioner by
clogging the air filter, mist eliminator, and coils. This will cause a restriction in the volume of airflow.
Accumulation of dust or sand in the condenser coil and/or in the compressor compartment may cause
overheating of the refrigeration system. Dust or sand may also clog the condensate trap and water drain lines.
Never operate the air conditioner without having the air filters in place.
b. Protection.
(1) Shield the air conditioner from dust as much as possible.
(2) Take advantage of any natural barriers which offer protection.
(3) Limit the amount of dusty or sandy outside air introduced through the fresh air damper.
(4) Roll down and secure the fabric cover on the back of the cabinet during periods of shutdown.
c. Cleaning.
(1) Keep the air conditioner as clean as possible.
(2) Pay particular attention to the outside grilles, condenser, filters, mist eliminator, louvers and electrical
components.
(3) In extreme conditions daily cleaning of condenser, filters, and outside grilles may be necessary.
The air conditioner is designed for normal exposure to the elements, so it is reasonably waterproof. Some of
the steps that should be taken in an extremely wet climate are:
a. More frequent inspection and cleaning of the mist eliminator, condensate trap, and drain lines to insure
proper drainage and prevent accumulation of water inside the cabinet.
b. Roll down and secure the fabric cover on the back of the cabinet during periods of wet, windy weather
when the air conditioner is not in operation.
c. Roll up and secure the fabric cover during dry spells when the air conditioner is not in operation so that
the interior can dry out and condensation will not accumulate.
