Bypass Function "Summer Operation - Helios KWL EC 270 W ET R Montage- Und Betriebsvorschrift

Installation and Operating Instructions
Passive house compact units KWL EC 270/370 W ET 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 bypas-
sing the enthalpy heat exchanger by means of two opposing bypass dampers.
Bypass closed: Outside air is led through an enthalpy 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 extract 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 extract 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
Fig.18
Bypass damper closed
9
EN
Fig.19
Bypass damper open