3.1.4
Hot water function
DHP-AQ Midi and DHP-AQ Maxi are adapted for hot water production.
Production of heating and hot water cannot occur at the same time
because the reversing valve for heating and hot water is positioned
after the heat pump and the immersion heater. Hot water production is
prioritised ahead of heat and cooling.
DHP-AQ Midi is connected to an existing water heater while DHP-AQ
Maxi has an integrated 180 litre heater equipped with a TWS coil (Tap
Water Stratificator) which gives more effective heat transfer and effi-
cient layering of water in the heater.
The temperature of the hot water cannot be adjusted. Normally, hot
water production does not cease at a determined temperature but
when the compressor’s operating pressure switch reaches its maximum
operating pressure, which corresponds to a hot water temperature of
approximately 50-55°C.
Using a regular time interval, the water in the water heater is given extra
heat by the integrated immersion heater to prevent the build up of bac-
teria, an anti-legionella function. The factory set time interval is seven
days (can be adjusted).
3.1.5
Defrost function
During operation the air heat exchanger is cooled by the energy
exchange, at the same time the humidity causes it to become covered
in frost at low outdoor temperatures. DHP-AQ has an automatic func-
tion to defrost the air heat exchanger using the energy from the house's
heating system.
Defrosting is initiated by low temperature in the refrigerant circuit after
the air heat exchanger and, among other things, is dependent on out-
door temperature, humidity and operating time. The length of defrost-
ing varies depending on the extent of freezing of the air heat
exchanger. Defrost continues until the air heat exchanger is free of ice
and the temperature starts to rise in the refrigerant circuit. After com-
pleted defrosting the heat pump returns to the operating mode before
defrosting.
3.1.6
Cooling function
The heart pump produces cooling through a similar process as the
defrosting function.
Cooling function is started by the heat pump control unit and is primar-
ily temperature controlled. The house's heating system is cooled by
User manual VUGFB102 – 9
