Just looking some advice on making my bathroom extractor fan smart.
Just trying to figure out the hardware side of things atm.
For context I’m in the UK.
After some research it seems that 2 most popular options are Shelly and Sonoff switches.
I found an post saying that Shelly shouldn’t be used for an inductive load like fan.
Does anyone know if that applies for Sonoff as well? Those of you who have done something similar, how did you deal with this?
I have an inline fan, connected to a standard 13 Amp outlet, I then put one of these in.
The sensor then turns the fan on when the humidity get too high. I have been very impressed with these very stable and can hold a good current.
Hi, I use one of the Girier Zigbee switch modules below to control my 3 speed extractor based on humidity i.e. if the humidity spikes due to someone having a shower then I run the fan at higher speed for a set period of time.
As shown by the diagram within the fan I just need to switch 240Vac onto terminals 1, 2&3, or 3 to select different speeds.
This is what the device looks like in HA:
Essentially I have it setup as follows:
Low Speed - background ventilation.
Medium Speed - run for a set period after the humidity spikes (this is from an Aqara sensor).
High Speed - runs when the light is switched on (this is as it was originally installed).
Hope that’s useful to you.
Have a look at this blueprint, I find it works a treat, took a while to get the settings right for my installation but then it just works!
Dumb Extractor Fan 
+ esp32 based wall switch (includes BLE 
) supercharged with esphome 
+ BLE Hygrometer = 
Poorly worded I would say. The maximum specifications for loads are typical for resistive ones. So if a device says it can handle 16A (or 10A) you shouldn’t put a inductive load with 16A (or 10A) but stay within more or less than 50%. That’s because inductive loads actually often use double the rated power at one time and no power the next moment (that happens very fast obviously) 
Thanks, this is just what I was looking for.
However I came across this on shelly support forum (My Shelly relay is restarting when switching on inductive load - such as fans, motors, roller. What should I do? :
)
Q: My Shelly relay is restarting when switching on inductive load - such as fans, motors, roller. What should I do?
A: To avoid that a RC snubber should be wired between Output and Neutral of the circuit. Еnergy absorbing circuits are used to suppress the voltage spikes caused by the circuit’s inductance when a switch, electrical or mechanical, opens.
Maybe that’s what I end up doing.
I was looking for an easy solution to make our bathroom extractor smart(er). I only used zigbee devices and the SmartLife app (logic). I have a reference TH (temp/humidity) sensor in my dining room, a TH sensor in the batchroom, a smart plug for the inline extractor fan (placed on my attic) and a zigbee scene switch.
When the bathroom humidity exceeds the reference humidity by 7% the extractor fan switches on. It switches off after 20 minutes (controlled by SmartLife logic). If the humidty is still above the 7% treshhold the process repeats itself.
The zigbee scene switch is placed in the bathroom and toggles the fan manually.
Automation example in SmartLife app: If bathroom humidity > 59% Then switch on Extractor Fan. Preconditions: Reference humidity <53% and Extractor fan off.
The extractor timer automation works like: If Extractor Fan switched on Then delay the action 20 minutes followed by switching the fan off.
