Bath exhaust fan automation - easiest approach

I’m finally taking the HA head-first dive in… the off-the-shelf products seem to have a lot of limitations.

This is the ideal situation - complete bath remodel…I have a blank canvas to work with. I’ve seen a number of Youtube videos automating a bath exhaust fan. Most seem to use DHT22 sensor and Wemos D1 mini wired for 5v…and I combine it with a Shelly 1 (as the relay). Any suggestions on the easiest approach, hardware, etc for a Noob (simpler the project + mimimal programing => increased likelihood of a second project!)?


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I would get a cheap tuya- related smart outlet, flash with esphome or tasmota, and grab a wyze contact sensor and/or motion sensor with the wyze componant…

probably $30 total, or less.

I’ve been thinking about a similar project. The bathroom light already has a Philips Hue bulb controlled by a motion sensor, which complicates matters since it means the power is always on - although they can easily be redeployed elsewhere.

I was wondering about a dumb fan powered from the light switch with a Lightwave smart relay which HA could switch on and off according to the humidity level detected by the Hue motion sensor (it’s humidity I’m concerned about, rather than other things…). However, I’m only considering Lightwave because I have a lot of switches and sockets already. If I were starting again I’m not sure I’d go down that route - I’ve found them a bit flaky.

I put a GE Z-wave fan switch inline with my existing bathroom fan up in the attic and it works great. The GE fan switch supports three speeds and is completely hidden out of sight (I use motion and contact sensors to turn my bathroom lights on and off). I have an Aqura humidity sensor that I use to toggle the fan up to high when the humidity rises above 70%, the rest of the time it runs on medium when the lights come on and then turns off 5 minutes after the lights go off.

I forgot about Tuya…downloaded the app a couple years? back but never followed up. That’s a simple solution.