Home Automation - Bathroom Extractor Fan

Is this what you’re referring to:CBi LED Dimmer Module Trailing Edge – CBI Online

Hi Richard

No, not the actual dimming module, just the switch that would go with it.
Swap them into the standard switches.

Exactly what I do!

The swappability of those work great because you can buy a two / three gang and only swop the ones you need. Not every light in my house is automated – yet.

Case in point:

Yeah I have three toggle-buttons on Sonoffs/Shelly’s remaining that irritate me to bits :slight_smile: Part of the problem is that it points the wrong way, but also that I can’t actually see the lights (and whether they’re on/off) as they’re outside. Still want to investigate a sort of light / LED that I can put on the 230v side and on the switch-plate to see if the lights outside is on/off.

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@ebendl ACDC sell some fairly small 230V LED’s, ive used some in the past as indication lights, maybe they have something that suites your needs. Now just swap out the face on that switch so it doesnt say “DIM”

All 4 automated, all 4 are dimmer switches, but have a clean look to them.

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Jeepers people have complex solutions. If I recall 85% humidity or higher, fan goes on, 70% or below, fan goes off.
I just wired it into an available slot on a Sonoff T1 light switch so I still have switch control.

@calypso sadly complex problems require complex solutions.

Here is an example, my shower, then SWAMBO’s shower, humidity stays above 70 for close to 2 hours, cant run the fan that long for 2 showers.

The above post made me want to add to the topic.
For those interested in the stats, a comparison of Humidity vs Temp in the same time period.

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Interesting – here’s mine:



Here’s the binary sensors – just remembered I have two (one for rising and one for falling):



The geyser temperature also gives a good indication when we showered - basically starting around 23:00 for 8 minutes:

Where do you get the ones which doesn’t say “DIM”? Haven’t seen those yet.

Thanks, will look into the 230V LEDs.

@ebendl im jealous of that geyser response, I have huge temp drops for the 2 showers, that being said, together they are much more than 8 minutes

Green line is a geyserwise thermostat connected to a d1 mini, yellow line is a ds18b20 ducttape to the metal flange above the thermostat.

For the switches, simply make them, they disasemble easily and i just swap the “white” bits.

interesting topic.

my shower ceiling fan has been in use for decades now via the light switch and recently via it’s own switch.

however my sex & soup provider forgets to switch the fan on when she showers :roll_eyes:

won’t a shower door & occupancy sensor work better?

It might. Occupancy sensor on its own I can imagine might be a pain when somebody uses the bathroom but not the shower and the fan turns on.

Then again, it might be a good idea :slight_smile:

Generally I’m quite happy with my setup - single sensor and it runs mostly as it should (and turns off automatically eventually).

was thinking to use the to together to prevent false triggers?

I havn’t had any false triggers on my latest setup, to be fair, the conditions can only exist when showering, chances of temp rising that quick and humidity being that high and no water is running in the room is very low. Using a presence/motion with a door sensor might work, but you’d want to check the shower door is closed and there is motion, motion sensors are heat dependent, I imagine the steam.heat could create false positives, also depending on the shower door, it would be tricky, as ours is always closed, its a swing door and not a sliding door that’s generally open when not in use.

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A quick question. Is that humidity, or relative humidity? Cause the latter is a function of temperature. Colder air holds less water. That means that lowering the temperature while keeping the moisture content the same actually increases the relative humidity.

If your charts show relative humidity, it makes complete sense that the humidity drops as the temperature rises from 10:30-ish onwards.

@plonkster I believe it is relative humidity, as that is what dht22 sensors measure.,

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Of course relative humidity is the one you care about, because when it gets too high it starts to condense on cold surfaces, causing mold and all sorts of bad stuff. Still interesting to see the relation on a chart.