You can buy bathroom fans with these built in.
And they are quite cheap.
Wondering if anyone had any ideas for a humidity sensor for my bathroom ? What I'm looking to do is detect if the room gets steam from the shower, and then get it to throw a relay connected to comfort to operate the fan! So 12v power and no/nc relay would be the requirement!
Thanks for that! I was hoping to get something seperate rather than combined, a bit more flexibility, and even to help with a sort of presence detection
You could always detect when the fan switches on.
Or you could use one of these and hook it up to a RaspberryPi or Arduino.
The sensor is a combined temp and humidity. So you could measure temp and humidity to get a better idea of what is happening. I have seen the humidity fans go off when the bathroom is not in use, as the humidity in the house is quite high. Though I guess you are in the UK so that shouldn't be a problem.