Hi,
I wanted to share a small project I’ve been working on.
Within my home I have a Brinks WTW mechanical ventilation unit which I wanted to add to Homey.
Purpose is to have Homey change the ventilation based on different parameters like moisture in the Bathroom when taking a shower, but also higher level of Co2 in other rooms, or when cooking.
This is at least for the Brink Renovent 300/400/450 series WTW unit, where a RJ12 connector is used combined with a 4-position switch.
I’ve used a Shelly-Uni, but every smart implant that is equipped with 2 outputs will do.
On the Shelly I also used one of the input for optional filter reminder.
Keep in mind that the highest output alwyas wins, so if you leave the 4-position switch on 3, Shelly will not be able to overrule it and vice versa.
Components used:
- Brinks WTW Unit 300/400/500 serie
- Switchbot humidity and Co2 sensors
- Shelly Uni + 12v power supply
- IPx mounting box
- Cat5e cable
- RJ12 connectors
- RJ12 splitter
Apps used:
-
Device Capabilities, to create a slider for changing the ventilation setting
-
BetterLogic, to display the current ventilation setting on the device tile
-
Advanced flows
Diagram:
I have created multiple flows, some for basic functions like making the 3-way slider button change the actual ventilation setting:
Note that Shelly Uni gives you 2 seperate devices, 1 per output.
Flow to notify you when you have to clean the filter. This is optional.
Normally the red led will be lid on the 4-position switch, but with the input on Shelly you can also put up a warning on the device in Homey, or have it send a push message. Whatever suits you.
And then of course the most important flow, to change the ventilation level based on humidity, co2 or other parameters. Mine is quite extensive, so probably a bit to big to put in here.
But I basically just set the slider to 0, 50 or 100 when humidity or co2 anywhere reaches a certain level. As a bonus I have a cooking hood connected with a smart switch that is doing energy measurements. So when it’s sensing the cooking hood is on based on the amount of power that is being used, it will also increase the ventilation system.
Lot’s of use cased here, use your imagination.
If you have any questions, or other suggestions let me know 
