from the outside air. The
compressor transfers this heat to
the indoor section. Then the fan
moves the warmed air through the
house.
Stage 2 — The BLUE light will
glow automatically when the
electric heaters are assisting the
American-Standard heat pump
unit maintain the comfort level of
the thermostat setting. This will
occur when there has been a
significant heat loss from the
structure, and when the
thermostat HEAT selector has
been abruptly moved up 3°F.
(1.6°C) or more.
How it cools
The circulating fan and coil extract
heat and moisture from the house
like a conventional central cooling
unit. This moisture is condensed
on the coil in the indoor section
and is piped to the drain. The
compressor transfers the
extracted heat to the outdoor coil
where the fan expels the heat to
the atmosphere.
How air moves
Supply Air — Conditioned air is
carried from the unit to each room
through the ductwork and enters
the room through the registers.
Return Air — Air goes back to the
unit through the return grille(s). A
filter in the return ductwork (or an
electronic air cleaner) filters the air
before it goes into the unit.
The heat pump system
discharges greater volumes of air
at lower temperatures than oil or
gas furnaces, thus the heat pump
avoids hot blasts of air and
maintains more even
temperatures throughout the
home.
Automatic Defrost
During the heating cycle and
under normal conditions of high
humidity or freezing rain which
occurs at about 30 to 40°F. (–1 to
4°C) outdoor temperature, there
may be a frost build-up on the
outdoor coil. Your unit will
AUTOMATICALLY reverse itself
and go into a defrost operation.
This normally will not last for more
than a few minutes. During defrost
it is quite possible that the supply
air will be cool which is normal.
Also under certain temperature
and humidity conditions, there will
be an emission of condensate
vapor from the outdoor unit. THIS
IS NORMAL. This condensate
vapor cloud, although of short
duration, can be quite large so do
not become alarmed. It is a good
indication that the unit is
functioning properly.