I thought I would share another one of my convenience projects and my journey in getting there.
When we bought our property last year, the on-suite bathroom to our main bedroom was a mess, there was clearly a problem with moisture at some point, paint peeling off the ceiling and some mold.
I presumed it was an issue with the elderly coupe who lived there taking nice hot showers with the window and door closed. As there is no air brick in the room.
1 Bathroom renovation and 6 months later proved me wrong, having the window open seemed to not have evacuated enough moisture and there was some mold starting to creep in on the ceiling.
Queue the bathroom extractor fan project. Fitted the extractor and wired it to a wall switch, voila, problem solved, it took only 3 days for my wife to be annoyed at herself for forgetting to turn it on and having to get out “mid shower” and to my surprise the first time ever, she asked if I could automate something.
The entire home automation concept has always been my “thing” much to her annoyance, she has admitted over the last year that some of the automation’s are “convenient”.
The extractor was fitted to a sonoff mini, to keep the WAF factor up, just like every light in the house, there is a manual switch for the wife, and I use my phone. a d1 mini in the roof with a sonoff temperature and humidity sensor right above the shower, I was lazy and in a hurry, the sonoff sensor comes in a nice enclosure and i didnt need to have one 3D printed for a dht22.
The next step was to work out the automation process, having monitored the data in grafana for a whole day, I was set, or so I thought. Fan turned on once humidity exceeded 60% and ran for 15 mins.
Test day 1, proved me oh so wrong, I took my morning shower, and it worked great, fan turned on and off as expected. SWAMBO went for her shower, and boom, in the brown stuff I was, it didnt work, Humidity had not dropped low enough to trigger again. I asume this is due to the placement of my sensor, and it might die sooner than expected, ill deal with that if it happens.
Much to my surprise, whilest brainstorming the solution that afternoon, i heard the fan turn on, you guessed it, the room had become just humid enough to turn the fan on, without any water running.
I figured, that serves me to set a higher set point. so we moved it to 70.That evening, SWAMBO decided to take a bath, she was not impressed when the FAN ran for 15mins and there was “no steam” in the room. Running her bath had gotten the humidity to 72%
After a few days and seeing what other people online had done, the basic setup was, just turn it on at 95%. I do still run it for 2 mins at 70%, and 5 mins at 80% to ensure no moisture is hanging around in the room.
I was fairly happy with the result, untill the weekend approached, our routine differs, normally I get up and shower way before SWAMBO does, my automation worked great, as humidity had some time to come down before she sowers and the fan would turn on. She had a shower and I had one after, needless to say the fan turned off in the middle of my shower. the following day, a similar routine except I waited 15mins to go shower, sadly humidity had not recovered enough and I manually turned on the Fan.
Lots of searching and digging and scrubbing through the data my new automation’s behave quite well.
I had found the Trend sensor in Home assistant nad had a fair amount of trial and error with getting mine setup right.
My first issue I assume relates to placement of the sensor, humidity stays very high 99/100% (dependant on who took a shower) for quite some time, however the temperature drops fairly quickly.
Shower occupancy based on Temperature
1 sensor if the temperature rises by more than 0.7 deg in 2 minutes
1 sensor if the temperature drops by more than 0.5 deg in 2 minutes
Temperature drops slower than it rises.
Shower occupancy based on Humidity
1 sensor if the humidity rises by more than 1% in 1 minute
1 sensor if the humidity drops by more than 1% in 1 minute
My final list of automations
Humidity above 70% run for 2 minutes
Humidity above 80% run for 5 minutes
Humidity above 90% and temp/humidity trend is rising, just turn on
If temperature or humidity trend starts dropping turn fan off
If fan has been turned on for 15 min, turn it off (a max runtime)
For the curious at heart some scenarios and data.
I shower, it turns on shortly after ive gotten in, as the humidity reaches 70%, it continues running due to the other automation firing. As my shower routine differs from SWAMBO, no shaving nonsense, humidity generally never exceeds 96-98% the fan turns off shortly after im done drying off, as humidity drops by 1%
SWAMBO showers, it turns on as expected, regardless of the time between showers, temp or humidity spikes and turns on the fan. It reaches 100% humidity and stays there for a significant amount of time after her shower, temp starts dropping shortly after she has gotten dressed, and the fan turns off.
Sorry for the long rad if you’ve made it to the end.