Underfloor heating grooving - experiences?

Hello,

if you combine panel radiators with underfloor heating, you have to set up two different heating circuits or buy new radiators for the basement.

A panel radiator either needs a significantly higher flow temperature than underfloor heating or a considerably larger surface area to provide the required heating output.

The new screed cost 15 euros per square meter and has the advantage that it is immediately walkable and coverable and no moisture is produced. Furthermore, 2 cm of screed was completely sufficient, as opposed to liquid screed, which requires 4-5 cm. Recasting in an occupied old building can become critical (weight, build-up height, all the moisture penetrates everywhere, e.g. into drywall walls). It would have been out of the question. In addition, there was an extra insulation of 8 cm PUR in the basement and upstairs the insulation was already sufficient due to the system panels of the underfloor heating (2.5 cm EPS). If there is a basement, I would possibly insulate the basement ceiling from below and then the insulation thicknesses of the system panels would also be sufficient. In our case, this was not possible because the basement is fully heated and was not insulated from below. So it had to be insulated from above.

if you combine panel radiators with underfloor heating, you have to set up two different heating circuits or buy new radiators for the basement.

That's right! Even if it sounds strange, it doesn't make much of a cost difference if you install underfloor heating in individual rooms in the basement as well.

Thank you very much for the information. I have also realized by now that the difference is supposed to be minimal. But why should the radiators be replaced?

Hello,

as already mentioned above, underfloor heating is operated with a significantly lower flow temperature (approx. 30 - 35°C) than a radiator heating system (approx. 50 - 55°C, in rare cases even up to 75°C).

If you now run your heating with a flow temperature of 30 - 35°C for the underfloor heating, the "old" radiators will obviously only be lukewarm.

To have the same heat transfer into the room, you therefore need radiators with a larger radiating surface to achieve the same heating output.

Regards,

Dirk

Okay, now I understand the context. Thanks for the explanation! On Monday, we will look at the property with the first heating engineer. I’m curious what he will advise me.