Zehnder Rittling ComfoAir 800, Manual

24 - EN

Minimum cooling supply air temperature (M10-16)

The control process does not stop at the set outdoor 
temperature of the high cooling point. In the event 
of lower outdoor temperatures, the unit will try and 
cool the supply air in accordance with the desired 
temperature set in parameter M10-16.

Minimal supply air temperature (M10-24 and 
M10-29)

The unit is preset with a minimal supply air 
temperature. The preset minimal supply air 
temperature can be changed in parameter M10-24. 
The unit will try to keep the supply air above the set 
value.

When the supply air temperature gets to cold the unit 
will activated failure E46 and turn off the supply air 
fan for at least a half hour. The minimal temperature 
at which the failure is activated is preset and can be 
changed in M10-29.

6.19  Frost protection

Only ComfoAir XL A: Modulated Frost Bypass 
(M11)

The ComfoAir XL A is equipped with a frost 
protection which uses the installed modulated 
bypass. This frost protection is preset and can be 
altered when desired in parameter M11. 

Function

Parameter

Setpoint exhaust temperature (T4)

M11-02

minimum supply temperature before the 
heater/change-over battery (T2)

M11-05

minimum supply temperature after the heater/
change-over battery (T5)

M11-06

Frost protection when T1 < Minimum outdoor 
temperature (T1)

M11-07

The bypass will function as frost protection 
when the outdoor temperature drops below the 
set temperature in parameter M11-07. When the 
outdoor temperature is above the set temperature 
in parameter M11-07 the bypass will functions as 
normal comfort control bypass for free cooling.

 The ComfoAir XL A is preset to balanced 

ventilation.

Plate Exchanger (M12)

The units are equipped with a frost protection for 
the plate exchanger. This frost protection is preset 
and can be altered when desired in parameter M12. 
When this frost protection is activated the unit will 
display error E43 and will power down or switch off 
the supply fan.

When the exhaust temperature drops below the set 
temperature in parameter M12-02 the supply fan will 
start reducing. When the exhaust temperature drops 
below the set temperature in parameter M12-03 the 
supply fan will turn off completely.

Pre heater (M13)

The pre heater can be used as a frost protection. 
This frost protection is preset and can be altered 
when desired in parameter M13.

Function

Parameter

Setpoint temperature (T1) for the pre heater 
installed in supply air).

M13-02

Setpoint temperature (T4) for the pre heater 
installed in exhaust air.

M13-06

Delay time for starting the frost protection of 
the pre heater installed in the exhaust air.

M13-07

Heater/change-over battery (M50)

To prevent the medium in the heater/change-over 
battery from freezing the heater/change-over battery 
is turned on when the outside air becomes too cold. 
This frost protection is preset and can be altered 
when desired in parameter M50. The temperature 
at which the minimum level of heating will turn on is 
set in parameter M50-04. The minimal control signal 
(percentage) of the heater/change-over battery is set 
in parameter M50-05.

6.20  Preset settings

Air k-value

All units are equipped with PI controllers for the air 
volume control. The k-value is determined by the 
installed hardware. Never change the settings of the 
k-value.

Frost thermostat on heater (M05)

A heater is equipped with a frost thermostat. The 
digital input settings of the frost thermostat is 
determined by the installed type of frost thermostat. 
Never change the digital input settings of the frost 
thermostat.

Fans (M05, M07, M08)

All units are equipped with fans. The digital input, 
analog output and communication port settings for 
the fans are determined by the installed type of fans. 
Never change the digital input, analog output and 
communication port settings of the fans.