Ideas for Motion Sensor for Kids Bathroom Lights/Fan?

So I picked up an Iris branded motion sensor and 3 zwave switches for my kid’s bathroom, and am finding it to be a bit of trouble. I basically wanted to ensure the lights go off after a certain amount of inactivity (5 minutes), but after freaking my 7 year old out on the initial bath test, I’ve had to rethink this.

What I want is pretty easy, turn off the lights if no motion for 5 minutes, but I don’t want the lights to turn on automatically. I also would like to automatically turn on the exhaust fan if the sensor goes above a certain temp.

Now is where the problems come into play. My kids sometimes shower/bathe with the door open, sometimes they’ll have the tub light on, sometimes they won’t, sometimes they’ll turn the fan on, sometimes they won’t. You get my drift.

So is there anything I can do besides just setting the timeout pretty high? I thought about changing it based on time of day, but then you’ll get those couple of situations where there is a problem. Looking for ideas.

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I have similar issue since I have 2 young kids as well. I ended up mounting 2 motion sensors on the ceiling and a humidity sensor. I use smartapps CoRE for automation.
The exhaust fan is simple since I have humidity sensor in there as well but for the light. I couldn’t do it with just one motion sensor.

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( i’ve moved this to projects so you can get individualized responses based on your own household’s requirements, and because there tends to be a lot of brainstorming in threads like this. :sunglasses:)

As you’ll find from some of my comments in other similar topics in the forums, I am not a big fan of inactivity turning off lights. Particularly in the bathroom, for all the reasons that you gave. But There are a couple of different approaches you can try.

If, and this can be a big if, everyone in your household closes the door when they go in the bathroom, then you can wait to start the inactivity timer until the door opens again. That will be easiest to do with core. But it gets really tricky if the kids are small and you have a parent who comes in and out, or if there’s anyone who doesn’t close the door all the way.

In the past, people have tossed a humidity sensor into the mix, basically automatically adding more time if the humidity goes up. That’s to account for people in the shower or the tub where they may not be detected by a motion sensor.

You can find some additional project reports by using the quick browse lists the community – created wiki, look in the project report section by room, and check the bathroom projects list.

Another option which might work better for the situation where parents might be coming in and out of the bathroom, or where you have two kids sharing a bathroom, would be to use a couple of motion sensors defined as a zone, one in the hallway just outside the bathroom, one in the main part of the bathroom, and if doable, one in the bathtub area. And delay the inactivity timer until there was no motion in all three of those areas.

Alternatively, as you mentioned, just bump up the inactivity timer to 45 minutes. That way the lights don’t get left on all night, but you’re not likely to turn them off when someone is still there.

This is just one of those situations were different solutions will work for different households, because it depends very much on what your own family’s usage patterns are.

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Install one of these:

They just became available so integration into ST might take a little while longer.

I would definitely set the delay to a much longer time as it gets pretty annoying to end up in the dark every 5 minutes if you are relaxing in a warm bath… Also, in the event your kids cannot get the light to come back on once in the tub, you certainly do not want them climbing out wet and in the dark to avoid any slipping hazards.

If you install LED light bulbs the cost of energy is totally negligible even if the lights stay on for a bit too long. My kids’ bathroom has 4 LED 60W equivalent bulbs that use less than 40W total… so they would have to leave the lights on for more than 25hrs to get to 1kWh (a few cents). Also, automatic off teaches them not to care while a delayed automatic off allows you to teach them to turn the lights off… and if they don’t then the automation will do so after 30 minutes (or whatever you pick).

As for the fan, I would try with a humidity sensor, not heat as the latter may trigger incorrectly. I have yet to implement something but I have done some testing where I came to the conclusion that a mere trigger point at X humidity is not going to work well. Relative humidity varies with the air temperature and thus its ability to carry water (sorry for non tech terms) so depending on temperature the trigger point may have to change. A possible solution would be to have a sensor in the room next door measuring humidity and if the one in the bathroom spikes up when compared to the one in the room next door, then it is a good indication that extra humidity is being generated. Maybe this is unnecessary but I was tired of a fixed setting (non zwave) humidity sensor turning on my fan at all hours of the day and night regardless of whether anyone was even using the bathroom.

Definitely not leaving the kids in the tub but more for toilet break or getting ready with brushing/clothing in the morning.


Take a look at the “bathroom light control” smart app I linked to in my previous post. The author uses both the average humidity in the room and an upward trend before triggering. He put a lot of work into it and it’s been quite popular for people who are willing to pay for the additional device to get the humidity readings. :sunglasses:

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@JDRoberts - I have a Zooz motion/temp/light/humidity sensor in the master bathroom so I will definitely give it a try. Thanks!


For those that want to use humidity I use the humidity level when the door closes as a reference point. When it climbs 5% with the door closed, I kick on the fan. If the house humidity level is low, I’ll turn the fan off when the door opens. (I have another app that controls the house humidity based on the outside temp. I live in Michigan, outside temp makes a difference here.) If not I’ll let it run until the level comes down or 60 minutes, whichever comes first. Lights are done with a combination of motion sensor and a door sensor. All is done using 2 or 3 rules in CoRE. I can’t remember the exact number of

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I went Keep It Simple Stupid and set up a rule in Core that says if the light in the bathroom Is on for more than 5 minutes then the fan will run for 20 minutes. If they are in there that long either it’s steamed up or something smells.

I have 17 y/o sons… that seem to fall asleep every time they sit for too long…
I also have 13 y/o son… and he’s quickly following in the other two’s tracks.
Then there is the 6 y/o son… bounces around like a rabbit.

In their bathroom I have this…

Sink lights on a GE switch
Tub lights on a GE switch
Fan on a GE switch
3 Iris motion sensors

  • one for the the sink and when the walk in
  • one for the toilet for those extended visits
  • one for the shower so the lights stay on in there.
    1 contact sensor on the door
    1 connected speaker
    1 Dot

I use Smart Lighting to automate the bathroom. All of my devices are eligible to run locally and I have the automations fairly simple. The only time the fan comes on is when the door is closed.
The lights stay on with the slightest bit of movement in the room.

I have 5 rules in SL

  • they are based on mode, days of the week, and which lights I want on at certain times.

This sounds like it may be the answer for me, more cheap sensors instead of trying complex rules with one more expensive sensor. Do you mount the motion sensor for the bath/shower on the ceiling?

Seems lots of fun for you automating it all but a bit overkill to just save some energy. It would take me years to recover the cost of all those sensors (door sensor, motion sensors) by saving on electricity. I pay between 2 and 12 cents per kWh (weird contract with rebates) and my kids’ bathroom has 4 x 60W equivalent LED bulbs (so about 40W total actual consumption) therefore the lights would need to be on for 25hrs to use 1kWh.

The only value I see in maximizing automation like this is the “cool factor” that for a geek like me is just a necessity :wink:

What do you use the Dot and speaker for in the bathroom? I have 6 echos and need more reasons to add more :stuck_out_tongue:

I don’t do any automation to save money… It’s all about cool factor.

I use EchoSistant to communicate messages all over the house with the speakers and dots. And to play music.


I don’t think we do this to save money. It’s more for convenience and wow factor. For me it’s the above and my OCD about leaving light on at night.
You would save way more money by making your heating and cooling smart.

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I agree with both of you. I do not do it to save money… and in the past couple months I have had the opposite issue where I needed to reach 1000 kWh to get a $100 rebate on my monthly bill. I succeeded in doing so being creative to use more power (cooking using oven instead of gas, oven self cleaning, running the AC a bit longer than actually needed, and so on) which sounds terrible for the environment but it saves me $100 on my bill. My last couple bills were between 20 and 40 bucks for 1000 kWh! Given every single bulb in my house is LED, the power used my them is negligible.

I do have 2 ecobee3 thermostats to control the 2 zone HVAC. A couple sensors get occasionally stuck reporting presence when nobody is there thus keeping my system on… annoying.

All my automation is for convenience and cool factor too but I try not to go overboard. I browse these forums in search of cool ideas.

You might also check the quick browse lists in the community – created wiki. Look in the project reports section, in particular at the “impress your friends” list. :wink:

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Why does your power company do this? They’re encouraging you to waste electricity then giving you a rebate? Or am I misunderstanding?

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I do not know what the end goal of such a contract is. I would assume anything they do is to entice you to use more. For those who do not monitor their consumption, this contract would be a good reason to not worry about using power as the $100 rebate brings the bill down quite a bit… that is IF you do not go over 2000 kWh at which point you pay the full amount. I wonder if this results in higher bills rather than lower for all those not actually getting to 1000. If I were not monitoring it, I would only get the credit a couple times a year but now I am actively doing what I can to get it.

I live in Texas and during the very few cold months I am around 800 - 900 kWh while during the hot months I usually float anywhere between 1500 and 2200 kWh. One of the past months where I was actively trying to hit the 1000 mark I got did not make it by a sliver so I ended up paying more than my average would have been without this incentive… However, since I started actively monitoring it and modifying what I do, I have increased usage but also significantly reduced my bill. In the summer months I will have to do my best to stay under 2000 so as to get the rebate otherwise my bill will be quite high.

Wow, didn’t know an electric company gives credit for using more and not the other way around. Quite an interesting concept.