There are 2 things I hate in bathrooms. One is mould. The other is noisy ineffective fans that buzz away for hours just because you turned the light on for 10 seconds. Luckily there is something you can do about both of these problems!
Firstly to minimise the buzzing quiet inline fans can be used to shift the noise further away from the room with ducting to send the air outside (https://www.ebay.co.uk/itm/Blauberg-Turbo-E-Inline-100mm-Mixed-Flow-Extractor-Bathroom-Loft-Fan-4-Powerful/284054443233?hash=item4222f6d4e1:g:xNQAAOSw6QRgHPFZ).
But in order to stop the fan coming on unnecessarily you need a humidity sensor in the room to only switch the fan on when it the room is humid. Luckily there are a plethora of these around now with ZigBee facilitating a way of having a low powered battery device that will last for years in exactly the location it is needed. I chose a Sonoff SNZB-02 (https://www.ebay.co.uk/itm/193766641820) to monitor the humidity to send a signal to the fan.
Now the fan is just a generic device with no intelligence so in order for it to respond to changing humidity levels a ZigBee relay was required. I had used these to create my Central heating controller so I just used another to switch the fan on and off (https://www.aliexpress.com/item/1005001830936644.html?spm=a2g0s.9042311.0.0.2b374c4dpxTLtW).
Next I used the Tuya Smart Life app to create 2 automations. The first to turn the fan on when the humidity levels exceeds 60%, the second to turn the fan off when the humidity levels falls back below 55%. All very simple and now the fan is only on when it needs to be on, regardless of whether the light is on or not.
BTW – the shower room has windows so I believe the current building regs allow for a fan that is switched on when needed.
One reply on “Gotta love the ZigBee”
Works really well. 😁