🚿 Bathroom Humidity Exhaust Fan

Love it. If you have any other questions just ask. Your use case is interesting.

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Hi again,

I have set the derivative sensor with a time window of 3 minutes as per your FAQ above. Initially I have set the autommation based on your blueprint to -0.5 & 0.5 so it did not triggered when the first event that I was looking for happened: my wife put some clothes to dry in the technical room to take advantage of the heat inside at exactly 9.31 PM, I have attached 2 graphs with the evolution of the 2 sensors.



What would be the best settings for me to trigger specifically when these type of events occur? The derrivative jumps immediately at 9.31 PM but then drops also abruptly at 9.53 PM while the humidity remains high and above the 25% threshold that I would like to see constant within the technical room. Please help me, I’m a bit lost.
Thanks in advance and kind regards.

Hi, I have attached below the evolution up to this morning of the 2 senzors, derivative and actual humidity, as can be seen the derivative is decreasing very abruptly because it has a 3 minute moving average while the actual humidity is decreasing over a longer time period.The small period in which the dehumidifier worked is because I trigerred it manually to see whether the switch is working.

By the way the graphs are before updating this morning to 2023.1.2, after that the derivative senzors do not show anymore like line graphs but instead like history bar.

@ionutm80 I will PM you.

In regards to @ionutm80 set up. We have created an new blueprint called Temperature Control Exhaust Fan.

Hi Blacky, nice blueprint! I want to use this blue print for my Itho box. Therefore I do not want to use a fan switch, because my fan is still running on status ‘low’ (percentage of the full speed of the fan) . The status is created with a ‘preset mode’ entity with status ‘low’ and ‘high’. So, now I want to use the instead of the fan switch a status of the entity. Is that possible?

@skipper79 Can you show me your entity ID. I going to update the blueprint with a extra option probably tomorrow. Maybe I will include this in the update. If not I can show you how to do it.

Also what state does the entity have? example ON / OFF

@Blacky, thank you for all these awesome blueprints! I’m trying to make the switch from SmartThings webCoRE since it just got shutdown. Unfortunately, my bathroom setup requires some combination of your Toilet Exhaust Fan and Bathroom Humidity Exhaust Fan blueprints and I was wondering if you could recommend the best course of action.

In my bathroom, the same fan handles toilet exhaust and humid exhaust. Sometimes, I’m just using the toilet and want the fan to be turned on manually via the in-wall smart switch and turn off after some set amount of time (say 15 min). At other times, I’m using the shower and want the fan to turn on automatically when the humidity rises and turn off when it drops. If turned on manually before the humidity rise, I want it to stay on until the humidity drops. Do you think any of your blueprints can support this scenario? If not, do you recommend I try to tweak one of them and if so which one?

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Sure. The enitiy is of the type fan with the following attributes:


preset_modes: []
percentage: 100
percentage_step: 1
preset_mode: null
temp: 17.8
hum: 73.8
ppmw: 9416
Speed status: 23
Internal fault: 0
Frost cycle: 0
Filter dirty: 0
friendly_name: Itho fan
supported_features: 1

And with the following script I define the presets:


To create a 3 button interface (scripts.yml)

#-----Mechanical ventilation presets
mv_preset_low:
  alias: MV preset low
  icon: mdi:fan-speed-1
  sequence:
    - service: fan.set_percentage
      target:
        entity_id: fan.itho_fan
      data:
        percentage: 33

mv_preset_medium:
  alias: MV preset medium
  icon: mdi:fan-speed-2
  sequence:
    - service: fan.set_percentage
      target:
        entity_id: fan.itho_fan
      data:
        percentage: 50

mv_preset_high:
  alias: MV preset high
  icon: mdi:fan-speed-3
  sequence:
    - service: fan.set_percentage
      target:
        entity_id: fan.itho_fan
      data:
        percentage: 100

So, with this I defined a button, for ‘High’, on my lovelace as follows:


  - entity: fan.itho_fan
    tap_action:
      action: call-service
      service: script.mv_preset_high
    icon: mdi:fan-speed-3

Try using two blueprints “Timer Relay - Run ON Timer and Bathroom Humidity Exhaust Fan” and select the same fan. Putting it all into one blueprint can be tricky. Both of the blueprints are mine and its why I have a few.

Us this blueprint Timer Relay - Run ON Timer

Use this blueprint Bathroom Humidity Exhaust Fan

Hope this helps you

Blacky :grinning:

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I will PM you.

Thank you for the advice. Just one follow up question - if I use both blueprints with the same fan, what would prevent the timer relay from turning off the fan in the middle of my shower?

@ydogandjiev Good question… your 100% right… my bad…brain fart!

The fan cant be a trigger. So… maybe, you can use a contact sensor on the toilet seat lid? (but who closes the lid right :thinking:) maybe a better option would be to use a distance sensor, so if someone sits on the seat the distance is close and this is the trigger? Maybe you can position a motion sensor that only picks up someone sitting on the toilet? If you can do something like this you then could use the Toilet Exhaust Fan and Bathroom Humidity Exhaust Fan blueprints and never have to manually turn the fan on again. Hope I am not having another brain fart.

You got me thinking though. I don’t have a toilet in the bathroom but I know a lot of people do… not promising anything but I am thinking about it.

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I’m having a bit of the same problem as skipper79. The automaisation starts up perfect. It goes to mode 3 of the ventilaton. But to turn the ventilation of, it should trigger mode 1. But I can’t define that.

@Kweetni01 This is different to skipper79 problem. Could you post your entity ID for 3 & 1.

These are “switch.mode_1_bad_2” for mode 1 and “switch.mode_3_bad_2” for mode 3.

@Kweetni01 Ok this is an edit to blueprint. I will PM you.

Is anyone else having or need to turn on with a switch and then turn off with a different switch?

@Blacky, for me the same. The automation starts with a script, but to bring it back to modes ‘low’ I have to trigger another script; ‘mv_preset_low’

@skipper79 Is it turning on and off? If not, how or what do you need to turn it off. Can you show me your entity ID for turning off.