The heat pump reduces the extract air temperature as much as possible without going below safety limits
and controlling the unit to produce maximum heating capacity at maximum efficiency. The max leaving
water temperature can be +60°C.
The Living HP unit can work in two modes: summer and winter.
4.2.1 Summer/Winter mode
Summer mode: when ambient air temperature exceeds set temperature value in the control panel (default
+20°C), a signal is sent to stop the extract air fan and heat pump. Dampers A and C are closed. Another
signal is sent to open fire/smoke damper B and to start fire/smoke fan in order for waste air from the
residence to be vented outside. In summer mode heat recovery is not possible.
Winter mode: when ambient air temperature goes below set temperature value in the control panel
(default +15°C), a signal is sent to stop fire/smoke fan, fire/smoke damper B will be closed. The Living
HP extract air fan and heat pump is turned on, dampers A and C are open, air travels through the unit.
The heat recovery is fully operational.
4.2.2 Fire function
Fire function is activated by smoke and fire sensor. The sensor must be mounted in the duct before
fire/smoke damper B. Fire function is used to protect the Living HP unit from smoke and heat in case of
fire emergency. If smoke is detected in winter mode the unit is stopped, dampers A and C are closed.
Signal is sent to open smoke fan damper B and to start smoke fan at full capacity immediately in order
to extract smoke from the residence.
In the summer mode if fire/smoke alarm is activated, the fire/smoke fan from regulation mode will be
immediately switched to full capacity. In normal conditions fire/smoke fan speed is controlled by the unit
based on differential pressure in extract air duct.
4.3 Heat recovering
The heat from extract air is recovered thought the heat pump to produce hot water, which then can be use
to heat the radiator system.
4.4 The cooling function
The refrigerant is circulated in a completely closed system in the following order: an evaporator, a
compressor, a condenser and the expansion valve. At the beginning of the cycle the liquid refrigerant goes
through the expansion valve, pressure decreases and cold mixture of liquid and gas enters the evaporator.
The expansion valve keeps a low pressure in the evaporator and controls stable superheating of refrigerant
gas. Heat is taken from extract air when passing the evaporator and therefore extract air temperature is
lowered. After the refrigerant leaves the evaporator coil it has absorbed heat from extract air and became
a gas. The superheated refrigerant gas enters the compressor which mechanically pressurizes the gas.
This process increases refrigerant temperature so the refrigerant leaves the compressor as the hot gas.
After a pressure increase in the compressor, the refrigerant gas passing the condenser is transformed into
fluid through condensation and thereby heat emission. Heat is submitted to the water circuit that is passing
the condenser. Heat has accordingly been transferred from the condenser to the water. After leaving the
condenser in a warm liquid state the refrigerant passes the expansion valve which drops the pressure on
the warm liquid and thus drops its temperature. The refrigerant leaves the expansion valve as a mixture of
cold liquid and gas and thereby the refrigeration cycle starts again.
4.5 Power control
The compressor (CPR) are step-less controlled between, in the frequency converter (FC), set minimum
and maximum frequency.
Operation and Maintenance Instructions
209531
7
Systemair AB
