PWM control for slow response Heating systems

[netrene]

I use TVR´s that control thermoelectric valves of a Floor Heating system which I think is a pretty common use case.

The TVR can only switch On/Off. The Floor heating has a delay of 8 hours. So basically it is kind of impossible to control it that way.

My proposal would be to use PWM to control the PVR.

So that would mean that BT uses a PID controller and the output of the PID is translated to Pulse and Pauses. So if the output of the PID is 50% the TVR would switch on for i.e. 10 Minutes (better adjustable) and then switch off for 10 Minutes (better adjustable). So I would only use 50% of the Heating capacity and avoid overshooting after 8 hours.

I think that would help a lot to improve the control of such systems.