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UAB KOMFOVENT we reserve the right to make changes without prior notice
DOMEKT_C8_21-01
3.6. Connection of external heating/cooling units
1
The following devices may be additionally connected to DOMEKT air handling units:
• Water heater.
• Water cooler.
• Direct expansion (DX) cooler/heater.
• Pre-heater (electric or water-glycol).
These accessories are intended for installation inside the supply air duct (except for the pre-heater). Pre-heater shall be
installed inside the outdoor air duct, upstream the air handling unit. A qualified specialist must perform all connections to
the heating or cooling system piping.
Non-freezing water-glycol mixture must be used as heat medium in a water pre-heater.
When connecting the heater/cooler pipes, they must be supported by a box spanner – otherwise they will be damaged. If
water is used in the heater, for frost protection water temperature sensor (B5), must be installed. It is screwed into the special
hole on the return water pipe. The sensor must be thermally insulated so that the room temperature does not distort water
temperature measurements.
Fig. 8.
Connecting the water heater/cooler hoses and installing the water temperature sensor
When operating the unit with negative outdoor temperature, a water-glycol mixture must be used
as heat medium in a water heater or cooler or it is necessary to ensure a return water temperature of
at least 25 °C.
Pipework package
2
must include circulation pump, which circulates heating/cooling medium
through the coil (smaller circuit) and 3-way mixing valve with modulated actuator. In cases if 2-way
valve is used, additionally it must be installed non-return valves to ensure continuous circulation
around smaller circuit. PPU must be installed as close to the water coil as possible.
2
Heat exchanger coil of DX coolers/heaters are factory-filled with nitrogen gas. Before connecting heat exchanger coil to
the refrigerant system, the nitrogen gas is discharged through a valve which is then cut off and coil connections are soldered
to the pipeline.
1
Ordered separately.
2
It is recommended to use PPU made by Komfovent.
