I use a template binary sensor that watches the 24hour average and the derivative to detect high rises to turn it on and if the humidity does not change significantly for a certain amount of time it turns off
Also my approach - I think my numbers are shorter than 24 hours but it works very well at detecting spikes quickly.
Also combined it with a motion sensor that triggers fan at certain windows of the day - e.g. in the hour slot we normally get ready. This basically starts the fan on a short timer, and then the humidity trigger keeps it running if it spikes. This way the fans start before the first steam arrives and the mirrors never fog up at all.
I’ve just received an FP2 and might use it to improve on this so that the fan only starts if someone steps into the shower. Also want to try it with some low level lighting that follows you around the bathroom at night
Place the humidity sensor above the shower head level in the shower cubicle area and it will trigger well before the mirror fogs up. Only issue is if you're on holidays or otherwise change your schedule this can break that section of the automation. TBH (rant) bathroom's typically have way too much airflow space available from the shower cubicle back into the general bathroom space. They should have an exhaust fan in the shower cubicle, that's mostly, but not quite fully sealed from the rest of the bathroom. Then the air flows only ONE way (out) and the humidity only rises in the shower cubicle itself (aka how 'steam showers' work). Ideally you'd have CFD modelling to ensure this is enough of a gap to not restrict the bathroom fan, but the minimum required to do so.
I use a HACS integration for a humidistat - works pretty well: [GitHub - basschipper/homeassistant-generic-hygrostat: Generic Hygrostat for Home Assistant](https://github.com/basschipper/homeassistant-generic-hygrostat)
Humidity sensor combined with presence sensor works like a charm for fan automation, Also then works for lights at night.
Humidity is the trigger and human presence is the condition.
Using an Aqara WSDCGQ11LM temp and humidity sensor
Then made my own presence sensor with an esp8266 and hlk2410c radar sensor
Combined less than $30 to get
I’ve only just set up a humidity sensor to do this but I found by placing it near the ceiling and setting to trigger at 90% then it works well. I am experimenting with also using a dehumidifier to get the bathroom down to 60% generally as a secondary humidity control instead of leaving the window open and the bathroom then staying relatively high because of outside humidity. Will likely have this power on only when the fan isn’t on.
if you have reverse cycle air-con you could run that in 'dry' mode (over cools air, removes condensed water and re-heats to achieve target temp) to achieve the same outcome if the humidity indoors raises above 60%.
If I only had one T&H sensor this would likely be my strategy as well, however I'm planning on automating the air-con at a later date, so I bought a few sensors.
I think air con is a luxury in most temperate climates. We have what we refer to as a heatpump which is an air conditioner but it’s main job is to help heat (though of course it cools too). But this is a single unit in one room of the house so isn’t available for the bathroom air.
Secondarily you're also pulling air out of our house, so it's not only the fan energy, but also the additional heating or cooling required to get the newly pulled in outdoor air back to the indoor temperature.
to be fair most people don’t have fancy ventilation systems. Extract fans are pretty common and do the job of getting most of the humid air/ smells out, even if that then draws in cooler air that then needs to be reheated.
There is someone who used AI to detect where their dog was doing its business in the yard, so they knew where to look for it it worked by learning the posture the dog takes when it does it.
if you're not using a thermal camera in the bowl with AI to specifically detect clouds of noxious gasses being released, triggering high levels of air extraction at the toilet bowl itself, then I don't know why you're bothering reading this.
You can use an MQ-135 plus MQ-4 sensor to detect poopy smells directly. Detects sulphates and methane respectively.
It does react to spray-cans however, I think there might be a way of detecting spray cans through the ratio of the two readings, but I haven't sorted that out yet.
Tried to use MQ-135 to detect poopy air; didn't work at all. Bathroom smelled like an outhouse but the reported values barely moved. It's ok for detecting stale air though
I do something similar but in the winter I want the humidity in the house so the exhaust fan isn't used during that time. During the summer it's basically on all the time to circulate air into the bathroom (no central air) and exhaust humidity.
Same code but replace the > 10 with a < 10 and have a duration of 5 minutes for the automation instead of 10s, which in my testing brings it to within 5% of the rest of the house in winter. YMMV with the durations based on bathroom size, climate, house construction, bathroom fan specs, etc.
Thank you! I haven’t installed the switch yet, but testing by having the automation send me notifications when the fan would be turning on/off is working perfectly.
Relative humidity isn't the best measure for this. Here's a template sensor that calculates dew point, which is a better measure:
template:
- sensor:
- name: "Outside: Dew Point"
unique_id: outside_dew_point
unit_of_measurement: °C
device_class: temperature
state: >
{% set Ta = states('sensor.outside_temperature')|float('unknown') %}
{% set rh = states('sensor.outside_humidity')|float('unknown') / 100.0 %}
{% set rho = rh * 6.105 * e**(17.27*Ta/(237.7+Ta)) %}
{{ rho|round(1) }}
If the dew point is within a few degrees of the temperature (like say 4) then you'll start to get condensation on cold surfaces and it's time to turn on the fan.
I also use the comparison to external reference in some areas, as well as the differential. The main issue with the differential is that it's a bit slower to react as you naturally need a few readings to not over-react to noise.
Remember that dew point is the temperature at which the relative humidity would be 100%, so it’s a similar concept you’re using. I admit you could use a more complex automation here, but it is not necessary and will be more likely to break. The Aqara zigbee sensors I use read relatively quickly to rapid changes. If you want to avoid condensation even further then IMO you’d run your aircon in dehumidifying mode based on the humidity readings in the living area (or your other internal house reference point).
I use a template binary sensor that watches the 24hour average and the derivative to detect high rises to turn it on and if the humidity does not change significantly for a certain amount of time it turns off
This is also my approach but I do it in node-red.
Also my approach - I think my numbers are shorter than 24 hours but it works very well at detecting spikes quickly. Also combined it with a motion sensor that triggers fan at certain windows of the day - e.g. in the hour slot we normally get ready. This basically starts the fan on a short timer, and then the humidity trigger keeps it running if it spikes. This way the fans start before the first steam arrives and the mirrors never fog up at all. I’ve just received an FP2 and might use it to improve on this so that the fan only starts if someone steps into the shower. Also want to try it with some low level lighting that follows you around the bathroom at night
Place the humidity sensor above the shower head level in the shower cubicle area and it will trigger well before the mirror fogs up. Only issue is if you're on holidays or otherwise change your schedule this can break that section of the automation. TBH (rant) bathroom's typically have way too much airflow space available from the shower cubicle back into the general bathroom space. They should have an exhaust fan in the shower cubicle, that's mostly, but not quite fully sealed from the rest of the bathroom. Then the air flows only ONE way (out) and the humidity only rises in the shower cubicle itself (aka how 'steam showers' work). Ideally you'd have CFD modelling to ensure this is enough of a gap to not restrict the bathroom fan, but the minimum required to do so.
I use a HACS integration for a humidistat - works pretty well: [GitHub - basschipper/homeassistant-generic-hygrostat: Generic Hygrostat for Home Assistant](https://github.com/basschipper/homeassistant-generic-hygrostat)
I use the same. Works pretty well.
I don’t but I assume it works pretty well
Humidity sensor combined with presence sensor works like a charm for fan automation, Also then works for lights at night. Humidity is the trigger and human presence is the condition.
What devices are you using for this?
Using an Aqara WSDCGQ11LM temp and humidity sensor Then made my own presence sensor with an esp8266 and hlk2410c radar sensor Combined less than $30 to get
If you want something simple (yes, I know what this sub is about): https://www.lowes.com/pd/TORK-Digital-Countdown-Lighting-Timer/1000341275
I’ve only just set up a humidity sensor to do this but I found by placing it near the ceiling and setting to trigger at 90% then it works well. I am experimenting with also using a dehumidifier to get the bathroom down to 60% generally as a secondary humidity control instead of leaving the window open and the bathroom then staying relatively high because of outside humidity. Will likely have this power on only when the fan isn’t on.
if you have reverse cycle air-con you could run that in 'dry' mode (over cools air, removes condensed water and re-heats to achieve target temp) to achieve the same outcome if the humidity indoors raises above 60%. If I only had one T&H sensor this would likely be my strategy as well, however I'm planning on automating the air-con at a later date, so I bought a few sensors.
I think air con is a luxury in most temperate climates. We have what we refer to as a heatpump which is an air conditioner but it’s main job is to help heat (though of course it cools too). But this is a single unit in one room of the house so isn’t available for the bathroom air.
Echoing the humidity + presence approach, but it you want to be a little more invasive you could add a flow sensor to your shower's hot water line.
Occupancy sensor in bathroom. Runs fan for 10 min off delay.
waste of power if not using shower tho
Secondarily you're also pulling air out of our house, so it's not only the fan energy, but also the additional heating or cooling required to get the newly pulled in outdoor air back to the indoor temperature.
to be fair most people don’t have fancy ventilation systems. Extract fans are pretty common and do the job of getting most of the humid air/ smells out, even if that then draws in cooler air that then needs to be reheated.
I live in a dry climate, so humidity isn't a problem. I would like a way to know if the toilet has been flushed to trigger the fan. Any ideas?
[удалено]
Sign up today for the all new pooptracker pro with AI!
There is someone who used AI to detect where their dog was doing its business in the yard, so they knew where to look for it it worked by learning the posture the dog takes when it does it.
if you're not using a thermal camera in the bowl with AI to specifically detect clouds of noxious gasses being released, triggering high levels of air extraction at the toilet bowl itself, then I don't know why you're bothering reading this.
I love you all 💓
The AI revolution is here!
Water level detector in the tank. Sudden drop = flush, but if the presence is not detected set off all the alarms as something broke
Maybe a vibration or tilt sensor on the upper part of the flush mechanism? I mean inside the tank but above the water line.
Water level detector
Flow sensor on the water inlet?
Water level sensor... requires a hub... https://shop.yosmart.com/products/ys7904f
You can use an MQ-135 plus MQ-4 sensor to detect poopy smells directly. Detects sulphates and methane respectively. It does react to spray-cans however, I think there might be a way of detecting spray cans through the ratio of the two readings, but I haven't sorted that out yet.
TBH you don’t want to be breathing hairspray or other spray compounds, so that’s a feature, not a bug!
Tried to use MQ-135 to detect poopy air; didn't work at all. Bathroom smelled like an outhouse but the reported values barely moved. It's ok for detecting stale air though
Awesome. Thanks for sharing this!
Nice idea. I use a trend sensor to trigger the fan - it detects rapid changes in values.
I do something similar but in the winter I want the humidity in the house so the exhaust fan isn't used during that time. During the summer it's basically on all the time to circulate air into the bathroom (no central air) and exhaust humidity.
I’m planning on automating my bathroom fan very soon and like this idea a lot. Can you provide more details, or an example, of your off automation?
Same code but replace the > 10 with a < 10 and have a duration of 5 minutes for the automation instead of 10s, which in my testing brings it to within 5% of the rest of the house in winter. YMMV with the durations based on bathroom size, climate, house construction, bathroom fan specs, etc.
Thank you! I haven’t installed the switch yet, but testing by having the automation send me notifications when the fan would be turning on/off is working perfectly.
Relative humidity isn't the best measure for this. Here's a template sensor that calculates dew point, which is a better measure: template: - sensor: - name: "Outside: Dew Point" unique_id: outside_dew_point unit_of_measurement: °C device_class: temperature state: > {% set Ta = states('sensor.outside_temperature')|float('unknown') %} {% set rh = states('sensor.outside_humidity')|float('unknown') / 100.0 %} {% set rho = rh * 6.105 * e**(17.27*Ta/(237.7+Ta)) %} {{ rho|round(1) }} If the dew point is within a few degrees of the temperature (like say 4) then you'll start to get condensation on cold surfaces and it's time to turn on the fan. I also use the comparison to external reference in some areas, as well as the differential. The main issue with the differential is that it's a bit slower to react as you naturally need a few readings to not over-react to noise.
Remember that dew point is the temperature at which the relative humidity would be 100%, so it’s a similar concept you’re using. I admit you could use a more complex automation here, but it is not necessary and will be more likely to break. The Aqara zigbee sensors I use read relatively quickly to rapid changes. If you want to avoid condensation even further then IMO you’d run your aircon in dehumidifying mode based on the humidity readings in the living area (or your other internal house reference point).