Great blueprint! Works like a charm!
The yellow bar on top is based on the heater hot water signal. I have a 10 second interval humidity sensor, that helps of course when working with derivatives. Sensor is away from the shower, close to the fan inlet.
Oh no thatâs not good. It is a bit tricky to set it all up⌠once you do I think you will realy like it.
Blacky 
Thanks for you kind words and sharing your positive experience. 
10 second interval looks realy good. Great set up⌠the graphs look perfect and I can see you have a 2 speed fan!
Hopefully more people like you will share their positive experience to!!
Enjoy
Blacky
Is there a way to add a time window for the automation? I donât want it to run between 11pm and 5am
So i have been using node red for this and i have just tried this blue print but I canât get it to run, not via the trigger or when manually selecting run. My entities are correct, derivative sensor is working. here is the yaml:
alias: Bathroom Exhaust Fan
description:
use_blueprint:
path: Blackshome/bathroom-humidity-exhaust-fan.yaml
input:
trigger: sensor.bathroom_humidity_helper
fan_switch:
entity_id: switch.bathroom_fan
rising_humidity: 0.5
falling_humidity: -0.5
time_delay: 3
include_max_humidity: maximum_humidity_enabled
month_winter_mode:
- "6"
- "7"
- "8"
winter_time_delay: 2
bathroom_humidity_sensor: sensor.bathroom_humidity
Have I missed anything?
I thought about this but realy the automation should always run. If you would like you can turn ON and OFF your automation using my other blueprint. 
Turn Light, Switch or Scene On & Off with Trigger Conditions. This will achive what you are trying to do.
Blacky
Not sure if you have seen the 2 FAQ
Q: How do you set up a Derivative Sensor Helper?
A: Please follow these steps Click Here
Q: I have set up a âDerivative Sensor Helperâ but how do i set up the automation settings?
A: Please follow these steps Click Here
For me to look into it further could you also provide your 2 graphs of your âDerivative Sensor Helperâ, âFanâ and Humidity sensor like the example below of my showers today.
Blacky 
The fan spins to max speed every time I restart HA. I think it has to do with the HA restart safeguard. The humidity derivative is lower than the ON trigger. Not sure how to report this issue but I can reproduce if needed.
If I follow the trace, it eventually arrives at
service: homeassistant.turn_on
target:
entity_id: script.ventilatie_high
Is there a way to disable the safeguard?
id: '1695374273928'
alias: 'Shower: Bathroom Humidity Exhaust Fan'
description: ''
use_blueprint:
path: Blackshome/bathroom-humidity-exhaust-fan.yaml
input:
fan_switch:
entity_id: script.ventilatie_high
trigger: sensor.badkamer_humidity_derivative
fan_speed_low:
- script.ventilatie_medium
bathroom_humidity_sensor: sensor.badkamer_relhumidity
include_max_humidity: maximum_humidity_enabled
max_humidity: 90
fan_speed_off:
- script.ventilatie_low
include_fan_speed: fan_low_speed_enabled
rising_humidity: 5
falling_humidity: -2
time_delay: 15
bypass_options: []
include_bypass: bypass_disabled
It works when running Node Red, but i want to give your blueprint a try. I dont think its my sensors, as it doesnât even run when i manually tell it to run.
Ok, it worked after a restart, but selecting run still doesnât activate. I was under the impression that manually running the automation is like the âtriggerâ activating?
Hi, Just put in a extra RV sensor to check the one i want to use.
Strange thin is that the helpers are set up exactly the same but they give a different outcome. one calculates in 0.1% and the other in %??
it also takes 6 minutes to respond. can that go faster? or is that dependig on the RV sensor?
On the left i use a tuya zigbee sensor, and on the left a el cheapo RF sensor. But that eats batteries so i wanted a different sensor not eating batteries.
I guess changing sensor wil do the trick, but it is strange that the helper does strange things with the value?
This is a good place to report it⌠I will look into it and thanks for letting me know
Edit: If required would you be interested in beta testing it?
Hey that is good news⌠I think you will love it now you got it up and running . It is a bit tricky and a bit of a love affair but once you nail it, it work well. I will have to remember that if someone else is having the same problem, thanks for letting me know and keeping me up to date.
No, see in your trace⌠it need a trigger, this is normal and how I designed it.
Enjoy
Blacky
This is probably what is going wrong. You need your humidity sensor to report a value every 60 seconds minimum. The derivative has a window of 3 minutes so it need 2 values within 3 minutes. @balk77 has a 10 second interval so it report realy fast and you are not standing in the shower waiting for the fan to come on. 6 min your shower will be over and that will be too slow. There are so many humidity sensors and best if you can adjust the reporting. Within a week I will show you one of my system as I have been meaning to do it but never got around to it. I think that will help a lot of people.
Blacky
Thank you. i also set a 10 second interval, but i guess the sensor does not update that often. I switched back again to the RF sensor, and ordered a huge amount of batteries with Amazon 
.
Still looking for the perfect sensor then.
It is the actual humidity sensor that need to report every 60 seconds min. The derivative has a window of 3 minutes. I will fully document my entire setup with the sensor and all the code so if you like you can copy paste. I will include photos and an easy step by step guide. Give me a week (it will probably be lest then, butâŚ) because I will have to pull some of it apart so you can see everything.
beta? sure, let me know. Is there anything else I could send you (traces for instance) that could help?
Thanks I just PM you for your trace line
Edit: I think I found it but will wait for your trace.
Hello. Please tell me what the reason may be. Xiaomi ordinary zigbee sensor, ordinary xiaomi zigbee socket. Automation is set up and running, while the time limit is 15 minutes. when 15 minutes have passed, the ventilation is turned off. The problem is that if the humidity is still high, the automation does not work the second time.
Thanks a lot for the answer.
