Comfoair Binding with EWT?

Add-ons Bindings
1

Hi Comfoair Users,

I read great things about the Comfoair Binding and I like to connect my Comfoair 350 to openhab as well! Thanks to @holger_hees for this one! I was in contact with him regarding the usage of an heat exchanger (EWT) with the binding.

The open question that I like to ask the Comfoair users with an EWT is, if the EWT is still active (and controlled by the Comfoair regarding min temp and max temp, on / off) when running the openhab binding.

Anybody out there running the binding with an Comfoair connected earth heat exchanger (EWT)?

Regards, Bernd

2

I guess there’s very little comfoair binding users, of which probably noone will have an EWT, so you won’t get any answer here (anyone to prove me wrong?)
There’s no obvious reason why connecting your Comfoair to openHAB would toggle EWT pump state.
So why don’t you just try it?
Btw, I have no Comfoair but a Vallox and an EWT. I’ve inserted a openHAB-controlled relais between the main ventilation unit and the EWT’s pump. That way I a) see its state and b) can en/disable the EWT from within openHAB (in addition to what my ventilation unit does).

3

Hi @mstormi ,
your are certainly right - just do it and see what happens :slight_smile:
However I have seen guys discussing this in the KNX forum a while ago, so still hoping for some feedback here…
btw: good idea with the relais for the EWT!

4

Just for all other EWT Comfoair user’s out there I though it might be useful to post the EWT item definitions. They are not listed in the usual sample item definitions linked to the binding. They allow to see the EWT upper and lower temperatures that have been set to turn on/off EWT, if the EWT is on or off and the % higher EWT speed (if set, otherwise 0)

Number Lueftung_EWT_Temperatur_Hoch "EWT Temperatur hoch [%.1f °C]" (Lueftung) {comfoair="ewt_temperatur_high"}
        Number Lueftung_EWT_Temperatur_Tief "EWT Temperatur tief [%.1f °C]" (Lueftung) {comfoair="ewt_temperatur_low"}
        Number Lueftung_EWT_Speed "EWT Geschwindigkeit [%.1f ]" (Lueftung) {comfoair="ewt_speed"}
        Number Lueftung_EWT       "Erdwärmetauscher [%d]" (Lueftung)      {comfoair="ewt_mode"}