Multiple Room Ventilation (Stosslueften)

Flows
1

I want to establish a best practice flow for Stosslueften (german which means ventilating more than one room by fully opening windows in multiple rooms and the connecting doors are open as well).

WHAT IS NEEDED?

  • smart thermostat which turns on/off the heating
  • some kind of sensors
    • (wind sensor in the hallway would be “best” but ugly and problematic with children)
    • contact sensors on the windows and connecting doors
  • a flow to rule them all :slight_smile:

I HAVE NOT found the perfect solution just yet. So I’m looking for advice.

I have defined a variable “Stosslueften” YES/NO.

When all windows are closed it is set to NO:

If multiple windows are open it is set to YES: (here I struggle most since there are almost unlimted combinations of windows which can be opened. In a perfect world we open always the same windows but most of the time just some of the windows. This makes it complicated for me. We have 8 rooms with windows. The rooms have between 1 and 4 windows.)

And this is the logic which triggers all smart radiators to shut off or resume to Auto

EDIT: sorry I am an new user here and can only embed images. here is a link:

https://drive.proton.me/urls/VC3RPZD4X8#zLVYr5i6TkHI

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Scherm­afbeelding 2025-12-15 om 11.24.05
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In your first and third flow you have more then one triggers before an ‘ALL’-card. Like the top flow in the screenprint. This will never run.

If one of the windows is opened, you will have to check the state of the other windows. Like the bottom flow.

Maybe this will work for you: if at least one window of each room is opened then set variable ‘Stosslueften’ to YES.

Imagine plafond 1 en 2 are windows in room 1 and plafond 3 en 4 in room 2:

Scherm­afbeelding 2025-12-15 om 11.41.15
Scherm­afbeelding 2025-12-15 om 11.41.152136×444 105 KB

1 Like
3

@Simon_Kai, programmed a Homey Script that can indicate when it’s time to ventilate (Stoßlüften).

To do this, temperature and humidity sensors are needed in the relevant rooms, as well as the current values from outside.

Just a suggestion.

1 Like
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Thank you! Regarding that idea: I do have CO2 sensors, which are another variable or even a complete replacement except in the bathroom where a humidity sensor is preffered.
After all: I don’t need that sophisticated calculation. Since we are proper germans (kidding) we do stosslüften daily at set times. So no need for notification.

I just want a DETECTION of stosslüften to shut off all thermostats.

I use tado X and have their subscription which includes an open window detection. It is okay but not 100% working all the times. Thats why I am looking for an advanced flow for detection.

PS: buying additional sensors is not an issue if you guy recommend any.