KNX & ventilation

Configuration
1

Hi,

I managed easily getting the value of my ventilation as a percentage using KNX.sensor.
I am now looking in how to set the value of ventilation. For instance writing some percentage to a KNX address.
I dont see any KNX component to perform that. Do you have an idea ? A custom component ?

Regards,

Eric

2

Does anyone know if it is possible to have a variation (dimming) component for KNX but not seen as a light ?
I am looking for a way to dimm ventilation from 0 to 100% (or 0 to 255 if seen as byte value).

Regards,

Eric

3

If you only want to automate it you can use the use knx.send service to send value to your ventilation controller.
Otherwise somebody have to create a KNX fan component (a lot of the code will be the same as in the KNX light)

4

I looked into this, and it seems not so easy. KNXLight extends Light but when looking at fan, it is a sub-component of climate. To declare a fan, you have to use “platform: fan” (doc here: https://www.home-assistant.io/components/fan/ )
KNX has a climate component to manage temperature, declared as “platform: knx” (doc here: https://www.home-assistant.io/components/climate.knx/ )
So the right way to manage a fan for KNX should be a climate sub-component. Am I right ?
But platform attribute is used to declare KNX, how could it also declare fan…
I am not a python developer at all so I may be missing something.

5

Climate and Fan are to different things:

  • climate devices control heating and cooling based on temperatures
  • fans don’t care about temperatures, you can just turn them off/on and change the speed

What is your device?

In any case if you’re not a Python programmer, it will be quite hard to create a component by yourself. You can try contacting the developer of the KNX library and see if he’s interested implementing this.

6

The device is a double flow CMV (Controlled Mechanical Ventilation) (is that a correct translation ?!). Model Helios KWL EC 500 Pro with KNX integration.
Thanks for your advices.

7

I don’t know what kind of KNX integration this provides, but most likely you will need a “FAN” component as this isn’t used to control the temperature.

8

Yes thats it. A Fan component with variation from 0 to 100% (or 0 to 255).
Maybe with some steps (ie: off=0%, low=25%, med=50%, high=75%, max=100%).
I may manage the KNX and python part by looking at the other components but what i am missing for now is the start… For KNXLight, Light was extended… Here i think the KNXFan component is a component that will not extend an existing hassio one.

9

For a Fan you will use the Fan class as the base class.

Best regards,
Daniel

10

Came up with a basic KNX fan component. Follow: KNX fan component