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Hot Gas Reheat Start-Up And Operation
General
Hot gas reheat units provide a dehumidifying mode of
operation. These units contain a reheat coil adjacent to
and downstream of the evaporator coil. Reheat coil
solenoid valve, L14, routes hot discharge gas from the
compressor to the reheat coil. Return air pulled across
the evaporator coil is cooled and dehumidified; the
reheat coil adds heat to supply air. See figure 31 for
reheat refrigerant routing and figure 32 for standard
cooling refrigerant routing.
REHEAT
COIL
FIGURE 31
REHEAT MODE REFRIGERANT ROUTING
STAGE 1
CONDENSER
COIL
STAGE 2
CONDENSER
COIL
STAGE 2
EVAPORATOR
COIL
STAGE 1
EVAPORATOR
COIL
SUPPLY
AIR
RETURN
AIR
OUTDOOR
AIR
TWO
CONDENSER
FANS
STAGE 1
COMPRESSOR
STAGE 2
COMPRESSOR
EXPANSION
VALVE
CHECK
VALVE
REHEAT
VALVE
REHEAT
COIL
FIGURE 32
COOLING MODE REFRIGERANT ROUTING
STAGE 1
CONDENSER
COIL
STAGE 2
CONDENSER
COIL
STAGE 2
EVAPORATOR
COIL
STAGE 1
EVAPORATOR
COIL
SUPPLY
AIR
RETURN
AIR
OUTDOOR
AIR
TWO
CONDENSER
FANS
STAGE 1
COMPRESSOR
STAGE 2
COMPRESSOR
EXPANSION
VALVE
CHECK
VALVE
REHEAT
VALVE
