Window wall air conditioning: Room air conditioners require comparatively little
maintenance, since their important components are in sealed units. But
since few people would think of calling a serviceman in for an annual
checkup of a room unit, doing a little preventive maintenance such as
cleaning the grills and radiators is a good habit if you want your
machine to keep operating at maximum efficiency and to last a long time.
Whenever the machine is in use, make sure there are no curtains, shades,
or large pieces of furniture positioned where they can block the flow of
air to and from the front grills. Also, make certain the unit is plugged
into a circuit of its own and that it has the kind of heavy-duty cord
required for a machine of that size.