TM 9-4120-403-14
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 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.
2-18. OPERATION IN DUSTY OR SANDY CONDITIONS
Dusty and sandy conditions can seriously reduce the efficiency of the air conditioner by clogging the air filters and
thereby causing a restriction of 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 mist
eliminator, condensate trap, and water drain lines. Some of the steps that may be taken are:
a. Frequent cleaning of filters and all other areas of dust and sand accumulation. In extreme conditions, daily
cleaning of filters may be necessary.
b. Limit the amount of dusty or sandy outside air introduced through the fresh air damper to that essential for
ventilation.
c. Roll down and secure the fabric cover on the back of the cabinet during periods of shutdown.
d. Perform Unit PMCS daily.
2-19. OPERATION IN UNUSUALLY WET CONDITIONS
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.
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