ASHP, radiators and UFH

[Mark Thompson]

Last year I had an ASHP fitted and radiators upgraded to suit. My question is, can I run UFH off the same circuit as the radiators, is there an appropriate TRV type valve and if so, do I use a lockshield valve too. I don't want to have it in zones, so still have my current thermostat to control the temperature 

[markocosic]

How big a a zone?

 

Danfoss FJ-VR return temperature limiter on the return set to slightly above room temperature will work for a small zone connected in parallel with the radiators.

[HughF]

What flow temp were the rads sized for?

[Mark Thompson]

Sorry about the late response, flow temperature is set at 50 C. Area is about 20m squared

[JohnMo]

That's hot for an ASHP, you need the flow reducing to about low to mid 30s to get a good CoP.

 

How are operating the system, long or short run times?

 

Is the system all plumped up or is the UFH an additional zone being added to the existing system?

 

On 16/02/2023 at 17:31, markocosic said:

Danfoss FJ-VR return temperature limiter

There an interesting valve, not seen them before.

[Mark Thompson]

The current system is all radiators but I would like UFH in the kitchen. The temperature setpoint is manufacturer's settings. I don't want to run in zones as it is a large house and we have the temperature nicely balanced now