HW, heating coil (water)


HCW/HW, heating coils (water)

Heating coil HCW/HW is an accessory for the VEX200 and VEX300 ranges. The coil is used to increase the temperature of the supply air. The coil can either be controlled by the EXact-/EXact2 control system or supplied for connection to a third-party control system. The coil is supplied without insulation.


Use of the heating coil is always recommended as part of the heat exchanger’s frost protection system, ensuring continuous operation even in very cold weather. To achieve the best basis for operation of each unit, calculations should always be carried out with EXHAUSTO’s product selection program EXselectPRO on www.exhausto.com.



Accessories for HCW/HW

Function/component Description
Temperature sensors, 4 different units

TE22: In the supply air duct to measure/control supply air temperature
TE-RPT: On the return pipe from the heating coil to keep the coil warm and protect it from icing
TS-RPT-X: To protect external piping linked to the heating coil from icing (additional purchase)
TE-SPT: Temperature sensor on supply pipe to the heating coil

Modulating motor valve Valve for variably regulating the flow of water to the heating coil, depending on the heat requirement
Circulation pump control

Control of the heating coil circulation pump 
Heat retention function (keeps heating coil free of ice) 
Built-in motion control of the circulation pump for periods that do not require heating.

Control system:
MHCW module

VEX with EXact control:
MHCW module for control of heating coil

VEX with EXact2 control:
If the distance between VEX and HCW coil is less than 10 m. the heating coil can be connected directly to the main board (IHCW)
If the distance between VEX and HCW coil is over 10 m, the heating coil must be connected to an MHCW module

Connecting the HCW coil

Connecting the water

It is important to connect the HCW coil correctly. See below...

Note: MVM is used as a general term for an engine valve.

Mixing loop 1:
Principle: Variable flow in the primary circuit (supply) and constant flow in secondary circuit (VEX unit):


Mixing loop 2:
Principle: Constant flow in both the primary circuit (supply) and secondary circuit (VEX unit):



Do not connect the heating coil like this!
Connection without circulation pump risks of frost damage!

rd12900, DO NOT

Explanation of simplified diagram:

Add all about the product series HW, heating coil (water)


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