Ämne: Thermostat with second heat source?

[Swing]

Hello,

I am from the Netherlands, so that is why the post is in English sorry.
I am studying how in Scandinavia the air/air heatpumps are used together with a different source.
Sometimes this second source is an electric heater, or a wood pellet heater for example.

Are there any thermostats in use that combine this function?
Meaning that they can control the airconditioning air heatpump, and when it it does not have enough power, turn on the second heating source?

Because most airconditioning, air/air heatpumps are controlled through infrared, and most other sources through 230v output.

Or is there typically no intelligent system that chooses between the two sources?

Thank you in advance

[Carl N]

I don't know any air/air heatpump that can control a second heat source.
The normal way is to use differens setpoints for indoor temperature, a lower for the second heat source.

[Swing]

I don't know any air/air heatpump that can control a second heat source.
The normal way is to use differens setpoints for indoor temperature, a lower for the second heat source.

Yes that is typically how it is done.

I am not expecting an air/air heatpump to turn on a second heat pump, they don't do that. That is something that air/water heatpumps can do from factory.

I am looking for a thermostat, that utilizes the air/air as first source, and then turns on second source of needed. Either by 230v or 24v, doesnt matter.

[Thompa71]

Put air/air at 23 degrees and “backup” at 20 so if air/air can’t hold temperature next will start.

[Carl N]

Yes that is typically how it is done.

I am not expecting an air/air heatpump to turn on a second heat pump, they don't do that. That is something that air/water heatpumps can do from factory.

I am looking for a thermostat, that utilizes the air/air as first source, and then turns on second source of needed. Either by 230v or 24v, doesnt matter.

I think you make it more complicated than it needs to be.
Air/air heat pump have a thermostat that control it, no need for a second one if it is supposed to be the main heat source, it should always be on.
So you just need to control the second heat source if the air/air isn't sufficient.
All solutions that works in this way needs a hysteresis (gap) between the start of the different heat sources so it's just to adjust the thermostat of the second heat source to start at a specific temperature indoor that indicate that the main heat pump isn't sufficient.