Does anyone have any recommendations for how to get my house to know when someone is smelling up the bathroom and address it automatically?
I already have exhaust fans on smart switches (and have cheap temperature and humidity sensors that could stay or go), but I don’t have any sensors for the volatile organic compounds (VOCs) in feces are flatulence. While a device to spray some air freshener when it gets really bad (either immediately or shortly after the room is vacated) might be nice, my main focus is a solution to know when the fan needs to be turned on and, after the situation has been addressed, back off.
I’ve found packs of VOC sensors for under ten dollars that would need to be paired with microcontrollers and air quality monitors for hudreds of dollars, neither of which am I sure I can set up to handle the job.
Does anyone know any (preferably inexpensive) hardware that could be used for proactively addressing bathroom air quality?
While more humane than bringing the cannery into the coal mine in just a well well ventilated cages, I would think the fitting the cannery with a gass mask would dramatically reduce increase the cost and reduce the efficiency. I’d also like to address the VOCs before they reach such toxic levels, but I like the out of the bax thinking.
Does anyone have any ideas that more directly integrate with Home Assistant?
While the VINDSTYRKA looks like a reasonably priced general room air quality monitoring solution that gets a lot of mentions in the forums, I haven’t seen anything that makes me think it would be good explicitly as a fecal monitor. However, please let me know if I’m missing something.
@mmstano, these links look promising. I’ll dig in some more (and probably consult friends with a better understanding of organic chemistry) and report back.
Be aware: while VOC sensors react on farting, they also will react to aerosols. so automatically dispensing more VOC’s in reaction to High VOC might lead to a cascade smelling worse than what is natural.
Thank you @mmstano for bringing up my post about the BME680.
I don’t know enough about fart-chemestry to recommend a sensor. Be aware that all cheap VOC and CO2 sensors are not an exact math. For the BME680, the VOC-values are just useless. But the ESPhome library offeres some sort af aggregation to provide a more or less usefull air quality indication.
Be aware that VOCs are everywhere: hairspray of you partner, perfume, bathroom cleaning agents, smelling candels, hair dryer, cheap toys, … have a look here to get the feeling: What are VOCs & why you should measure | Airthings
In short: don’t use VOC sensor for your use case, as it might lead to unwanted effects. (Or perhaps its not the smell, but the chemicals that you would like to get out of the house?)
Did anybody try one of the cheap methane and sulfur sensors? Any experiences with those?
@alanmeck: you have asked about hardware. I have built a couple of sensors myself. The easiest way to do so in my experience:
Chip: Wemos D1mini for one or two sensors. If you would like to use bluetooth or more sensors and small displays, go for something more powerfull: Any ESP32 should do. Both are cheap if you order them far east. (have a good look at western recommendation on the supplier…)
Software: ESPhome. It needs some learning curve, but with some examples you get there. (My first sensors have been based on Tasmota, but ESPhome integrates better into HomeAssistant and is more powerfull.)
If it doesn’t have to be battery powered, esphome approach is probably the way to go. You can try cheap VOC sensor or MQ-136 for more specific odor detection.
For what it’s worth, a different approach (might not suit your situation): i monitor increase of water flow. Which will detect shower useage, but also flushing toilet. Inreased flow for x amount of time, just turn on the venitlators and whatever you deem is needed.
How about a wall switch for the fan, and any time it is turned on have it run atomatically for 10 minutes, also any time the light is turned on have it run for 10 minutes, won’t air freshener spray set off any VOC sensor? Also BTW if you use Shelly relays and it gets very humid in the bathroom from long showers etc. - the relay will start to fail (- it will flicker like crazy - poor man’s workaround is to seal the relay into a plastic bag with some desiccants such as are found in prescription bottles etc.)
Same, pressure strip wired to a zigbee sensor under toilet lid so I don’t need to hook it up for power.
I dunno if you can find something that can accurately measure those methane gas
The most effective thing I have see is having the exhaust fan located in the wall adjacent to the toilet. (You might also want to have the offender see a doctor.)
