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INSTALLATION OPERATIONS AND MAINTENANCE MANUAL - RXC/Hi SERIES
6. OPERATING MODE
6.1 Winter operating mode
The return air, after passing through the cross-flow heat recovery, goes to feed the heat pump source exchanger that operates as
an evaporator.
Through the vapour compression refrigeration cycle, the fresh air, coming out of the cross-flow heat recovery, is heated by the
heat pump user exchanger, which operates as a condenser. The modulation of the thermal capacity, obtained through the inverter
compressor, will allow to precisely control the supply air temperature.
During heating operation, the evaporator of the heat pump may be subject to the formation of surface frost with consequent loss of
efficiency. To prevent this from happening, the unit provides controlled management of a defrosting cycle obtained by reversing the
refrigeration cycle. During this phase the return fans are stopped and the compressors forced at maximum speed. Through
the additional heating resources present in the unit, water heating coils or electrical resistances, the supply air temperature is
maintained at a suitable value so as not to disturb the internal environment.
6.2 Summer operating mode
The return air, after passing through the cross-flow heat recovery, goes to feed the heat pump source exchanger, which operates
as a condenser. The fresh air, after passing through the cross-flow heat recovery, is cooled by the heat pump user heat exchanger,
which operates as an evaporator.
6.3 Free-Cooling operating mode
When the outside temperature is lower than the inside temperature of the room to be air-conditioned, if this needs cooling, the
units operate in free-cooling mode and all integrated heat recovery stages are disabled.
