3 alternatives for shower, which is the best?

Hi everyone,
I am just starting to plan for a shower + light + fan automation…

The easiest for me would be to place a motion sensor inside the shower, but I am concerned that à cheap sensor like the SONOFF ( I have a few spare ones) would be damaged with the humidity inside the shower. Is there indoor sensors that can do the job and resist 100% humidity?

Another idea would be to use a flood sensor, however I never experienced them, can they react to a shower water jet, or do they need to be completely flooded ?

Lastly, I have easy access to the shower pipe right behind the shower: any recommendation for the type of temp sensor I could attach to the copper pipe, and how it would communicate the temp change to the hub ?


Some water sensors can be connected to leads which will detect water when the two are « joined » by water. Those could potentially work if added to the drain if it is made of PVC (not metal). If made of metal, a temperature sensor should work well assuming you do not shower with room temp water. :slight_smile:

Do I understand that you want to ensure the light stays on while in the shower and that the fan turns on when the humidity gets to a certain level?

What I have done that works quite well for both my wife and I is:

Bathroom has a 4-in-1 sensor - light needs to be turned on manually. Will turn off automatically after no motion for 4 minutes. (Using @bertabcd1234lights on motion plus app). I prefer to get ready in the dark - helps me fall asleep afterwards. My wife, not so much.

Shower - light needs to be turned on manually. Will turn off automatically after no motion in the bathroom for something like 20 minutes (needs to be longer than the longer we will typically shower for).

Humidity - I compare the humidity levels from the bathroom and another 4-in-1 and turn on the fan if the humidity is greater by a certain % in the bathroom than in the other room. There are also apps that will turn it on based on a single sensor’s humidity level.

I have motion activated lights, the sensor sits where it can see nearly every corner of the room including the shower. It is an Iris V3 that is mounted above and near the shower but not in the shower. I never have problems with the main lights (which includes the one in the shower) falsely turning off unless you are literally standing still for minutes at a time. The sensor seems tolerant of the humidity, but it never sees either direct or indirect water spray.

The fan is controlled by humidity from a second dedicated humidity/temp sensor, and utilizing one of the community smart bath fan apps. It does a terrific job watching rate of rise of humidity to trigger the fan, and time and humidity rate of fall to turn off.

My experience with water sensors is that they have to be pretty much perfectly dry to say "dry". If there is one drop on them, they will say wet. And the shower being wet doesn't necessarily correspond with humidity levels in the bathroom.

I don't have a suggestion for measuring water temp, and I am not sure what or why you would want that exactly. Not that I think it is a bad idea necessarily, just that I haven't heard of that being done

I keep things simple. All showers have a separate shower light. When that turns on it also turns on the fan and it will stay on for 20 minutes after the shower light turns off.

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I use the manual on and auto off concept on the shower light and a zooz 4 in 1 for the bathroom lights on motion. I use the humidity reading to control the fan using the “Smarter Humidity Fan” app. It works great.

A Hue outdoor motion sensor would work just fine, although the size and color may not be what you're looking for. They're quick to trigger and generally well regarded by folks in this community. You could also just seal the SONOFF with some sealant. There are posts elsewhere about sealing up indoor sensor for use in wet/outdoor locations.

For the temperature sensor, I believe the Fibaro smart implant has the ability to connect a temperature probe. It would require a wired power source.

Guy, I am satisfied with my new setup: I used an Aqara leak sensor inside the shower, to start the fan and bathroom light, it works perfectly and it is really fast!
The only thing is I had to stick it with a suction cup to the shower wall, that way it is sitting vertically and drys a lot faster than when sitting on the floor. I bought the Aqara for about 25 US (35$ Canadian).


That is an interesting solution. I am using Konke humidity sensors to trigger the fans. Originally did what @ritchierich did but the FAF (Family Approval Factor) was surprisingly low which was frustrating.. also can't do motion sensors in the bathroom either sigh...

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