Hey,
I have a Venmar K8 HRV in my house that I currently control via the little button on it's side to toggle it between off/low/high.
This is the model:
https://www.venmar.ca/50-air-exchangers-k8-hrv.html
And this is that button:
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By default I have it just run on low 24/7 and then just sometimes switch it to high if we have more people over etc.
Currently there is no controller attached to the Unit, so that button is the only way to control it. But I'd like to be able to control it remotely, so I was hoping I can connect some WiFi controller to it, maybe some ESP32 or similar.
The software side of things is no problem for me, I know very well how to do that part. But I have limited experience when it comes to hardware and electronics, and so am a bit lost for how I would have to hook such a controller up.
I looked the the user documentation for the HRV: https://www.venmar.ca/DATA/DOCUMENT/1504_4_en~v~user-guide.pdf
And it seems that if you look at page 13 (7.1.4) it seems like that wall control unit is connected via two cables to the G and B connector and is able to somehow control the off/low/high setting.
This means, I should be able to hook something up between G and B that I can control remotely, right?
Has anyone ever done that?
Does anyone know what signals are sent between G and B?
Any help would be much appreciated!
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Vanee will tell you to use OL and OC but B and G will work with the Ecobee AUX terminals and that will give you access via the Ecobee app. I believe only the Ecobee 3 lite version does not support a ventilator. You will have to use a 24V transformer to power the Ecobee RC and C terminals.
You can buy a 120V male plug and install it on this transformer and plug it into the wall near the HRV then use low-voltage 2 wire and connect the two terminals to the RC and C on the Ecobee. Then connect the HRV OL and OC terminals to the Ecobee AUX terminals. (The transformer black wire goes to the 120V plug brass connection.)
Honeywell 24V Transformer (https://www.amazon.ca/Thermostat-Doorbell-Transformer-Compatible-Honeywell/dp/B07L9X9V57/ref=asc_df_B07L9X9V57/?tag=googlemobshop-20&linkCode=df0&hvadid=341629586364&hvpos=&hvnetw=g&hvrand=18140950137870633477&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9104499&hvtargid=pla-601412827827&psc=1)
In the Ecobee settings there's a way to set up a heat recovery ventilator without a furnace or AC.