Dehumidification Circuit; Figure 21 Circuit Diagrams - Bard WG241D Installation Instructions Manual

34. DEHUMIDIFICATION CIRCUIT

The dehumidification circuit incorporates an
independent heat exchanger coil in the supply air
stream. This coil reheats the supply air after it passes
over the cooling coil without requiring the gas burner
to be used for reheat purposes. This results in very
high mechanical dehumidification capability from the
air conditioner on demand without using gas reheat.
The dehumidification refrigerant reheat circuit is
controlled by a three way valve directing the
refrigerant gas to the normal condenser during periods
when standard air conditioning is required. During
periods of time of low ambient temperature
(approximately 65° to 75° outdoor) and high indoor
humidity, a humidistat senses the need for mechanical
dehumidification. It then energizes both the
compressor circuit and the three way valve, thus
directing the hot refrigerant discharge gas into a
MIS-1200
DEHUMIDIFICATION MODE
CIRCUIT DIAGRAM
Manual 2100-376
Page 47
separate desuperheating condenser circuit which
reheats the conditioned air before it is delivered to the
room. The refrigerant gas is then routed from the
desuperheating condenser to the system condenser for
further heat transfer. A small orifice inserted between
the reheat coil return line and suction line will prevent
liquid from accumulating in the reheat coil when it is
inactive. This drain does not affect the normal
operation of the system. A check valve is located in
the reheat oil return line. It has a soft spring to hold the
ball on the seat. This will make the method of
checking the ball freedom with a magnet difficult.
Refer to Figure 21 for the location of the check valve
and drain back capillary. When the humidistat is
satisfied, the system automatically switches back to
normal air conditioning mode and either continues to
operate or turns off based on the signal from the wall
thermostat. The result is separate humidity control at
minimum operating cost.
FIGURE 21
CIRCUIT DIAGRAMS
AIR CONDITIONING MODE
CIRCUIT DIAGRAM
MIS-1199