Installation and operating instructions
Passive house compact units KWL EC 270/370 W R/L
3.2
Bypass function "summer operation"
The bypass function enables a reduction of the supply air temperature and ensures a pleasant indoor
climate by bypassing the heat exchanger by means of two opposing bypass dampers.
Bypass closed: Outside air is led through a heat exchanger into the room (heat recovery active)
Bypass open: Outside air is led directly into the room (heat recovery inactive), indirect cooling of room
air
– Functional description Bypass:
If the KWL is supplied with mains voltage, the bypass damper closes completely (Fig.18).
The bypass is opened when all conditions are met:
Condition 1: The extracted air temperature (sensor T3) is higher than the bypass temperature (bypass
temperature min. +3 °C higher than supply air temperature see auxiliary heater, factory
setting +23 °C).
Condition 2: The outside air temperature (sensor T1) is lower than the extracted air temp. (sensor T3)
Condition 3: The outside air temperature (sensor T1) is higher than the outside air limit (factory setting
+15 °C)
The bypass is closed if conditions 4 and 5 or 6 and 7 are met.
Condition 4: The extracted air temperature (sensor T3) is lower than the bypass temperature which is
reduced by -2 °C.
Condition 5: The bypass is open
or
Condition 6: The outside air temperature (sensor T1) is lower than the outside air limit which is reduced
by -2 °C.
Condition 7: The bypass is open
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