Operating instructions

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SECTION E. ROOF-MOUNTED HEAT PUMP OPERATION
E. OPERATION
The heat pump operates in two different modes: cooling
and heating.
The same mechanism is used for both cycles, but the travel
or flow of refrigerant is reversed to change from cooling to
heating. The items used to accomplish this are a compres-
sor, an inside coil, an outside coil, capillary tube or tubes
(the metering device/s), a series of copper lines (refrigerant
grade tubing), a reversing valve, an air movement system
(motor and wheel or blades), and refrigerant (R22).
1E. THE COOLING MODE
To cool the air inside a structure, heat is removed from the
inside air and released to the outside air or ambient.
To accomplish this, first air flow is established to pass
over both coils (inside and outside). Next, a refrigerant
cycle is established to cause refrigerant (R22) to flow
through both coils.
The refrigerant cycle starts at the compressor. Its
function is to take the low pressure R22 vapor and dis-
charge it as high pressure vapor. As the refrigerant (R22)
is compressed, it gives off heat causing the discharge line
to be quite warm or hot to the touch in hot weather.
The R22 high pressure vapor leaves the compressor
through the discharge line and enters the reversing valve.
The reversing valve routes the high pressure vapor to the
outside coil. In the cooling mode, the outside coil is a
condenser coil.
The high pressure R22 vapor enters the outside coil
(condenser). Here it is cooled and condensed into liquid
R22 by passing through the coil. The heat removed from
the refrigerant is expelled to the outside air. The refrigerant
leaves the outside coil as high pressure liquid.
As the high pressure liquid R22 leaves the outside coil
(condenser) it passes through the small capillary tube or
tubes. This is the metering or flow control device in the
sealed system. It determines the amount and force of
which the R22 enters the inside coil. It is
imperativeimperative
imperativeimperative
imperative that
the capillary tube's length and diameter not be altered. If the
tube is altered, the unit will not operate as efficiently as it
should.
The high pressure liquid R22 enters the inside coil in a
controlled amount from the capillary tube. When the liquid
enters the low pressure atmosphere of the inside coil
(evaporator) it evaporates into vapor. When the evapora-
tive process takes place, heat is removed from the air
flowing through the inside coil (evaporator). The air with the
heat removed is returned to the inside of the structure via
the air movement system (blower assembly).
From the inside coil (evaporator), the low pressure
refrigerant (R22) vapor returns to the reversing valve. The
reversing valve routes the low pressure vapor to the
compressor through the suction line to start the cooling
process again.
2E. THE HEATING MODE:
To heat the air inside a structure, heat is removed from the
outside air or ambient and released to the inside air.
To accomplish this, first air flow is established to pass
over both coils (inside and outside), Next, a refrigerant
cycle is established to cause the refrigerant (R22) to flow
through both coils.
COOLING MODECOOLING MODE
COOLING MODECOOLING MODE
COOLING MODE
HEATING MODEHEATING MODE
HEATING MODEHEATING MODE
HEATING MODE