I share this experience. Perhaps it will inspire some of you.
So I’m planning to do a wine cellar in my basement. I want to monitor temperature and humidity before the works. I’ve put a Xiaomi temp/humidity/pressure sensor on a PVC pipe to avoid putting down on the ground.
What a surprise when I see some peaks on temperature. Indeed, my sensor is on the water evacuation pipe of the house. And I soon as someone is taking a shower, the temperature is rising from 16°c to 19°c in few minutes
So with simple rules I can potentially:
Know when someone is in the shower in my two bathrooms. Generally motion detector are not so efficient in a bathroom when you are under the shower.
Monitor the number and duration of the showers taken by the whole family
Perhaps it was already known but I didn’t expect this behavior. I hope it will inspire some of you.
When I will have some spare time, I will try to put logics and calibrate the sensor to count and mesure the duration. It should be more efficient with the sensor tape on the bottom of the pipe.
I have a temperature sensor mounted on the wall that is right next to a heating duct inside the wall. Whenever the forced-air furnace activates, the temperature sensor detects the warmth from the duct.
In my case, it was just a bad choice of location for the temperature sensor … but the principle is the same.
The neatest idea I remember for ‘tub presence’ is a strain gauge glued to the bottom of the tub (under it, of course).
It can’t be fooled by hot water simply running down the drain and you can detect the difference between:
a person standing in the tub taking a shower
a tub full of water minus a person
a tub full of water plus a person (or three)
I learned about this technique many years ago and vowed to do it one day. All I needed to do was open the access hatch, reach under the tub, and epoxy the strain gauge to it.
I never did … but the idea is sound, as is monitoring the temperature of the drain pipe.
Depends on pipe work i guess whether the pipe you are testing has t piece off to other units like mine where the hot water unit is outside the bathroom and the pipe enters the house via shower mixer and then t’s off to the rest of the house.
By chance in my case the kitchen, the dishwasher and washing machine are after the sensor.
In the bathrooms the other usages have short duration. The pipe behavior is similar to a low-pass filter.
I didn’t try the result with emptying the bathtub.
I use two Sylvania motion sensors in my Bathroom - one above the toilet and one in my Shower caddy –
I have a Node-Red flow that waits for the closest sensor to the door to be triggered then starts polling. After the initial wait, it goes to an [if… and] flow checking if the motion has ceased and also branches out to a 1 sec poll that kicks off an [if… or] flow checking if there is any motion from the two sensors. If the [if… or] flow returns true, the polling is restarted. If the [if… and] flow returns true, it shuts the lights off.
