ᐅ Experience with Retrofitted Milled Underfloor Heating in Older Buildings

Hello,

I am currently renovating my condominium.

A brief overview of the apartment:
It was built in 1980
Located on the first floor
Double glazing
I have already replaced the roller shutter boxes with new modern ones

Floor structure:
2.5cm (1 inch) polystyrene boards
The rest is screed up to a total thickness of 10cm (4 inches)

My plan is to install a new gas heating system and additionally mill in an underfloor heating system.

The heating engineer told me that the pipes would only be milled 2cm (0.8 inches) into the screed.

My concern is that, since the apartment is on the first floor, the heat might be lost.

Has anyone had experience with this type of underfloor heating?

Thank you very much!

Additionally:
The current heating system is located inside the apartment. Therefore, the manifold would also be located there accordingly.

haadaa123 schrieb:

Has anyone had experience with this kind of underfloor heating?

In the end, it’s just a regular underfloor heating system. The downside is the relatively high cost (new screed is similarly expensive) and the less flexible pipe spacing. However, its performance is the same as other systems.

But: Please remember that you need approval from the homeowners’ association for this construction work. Also, you might not be able to connect the underfloor heating directly to the new gas heating system. You may need a mixing valve to reduce the high supply temperatures of the gas boiler to a suitable level. Just keep that in mind during planning.

Oh, and regarding heat loss downwards. Yes, you will have it. You’d probably have it with radiators as well if the floors above and below are not heated as much as your place. If you want to minimize heat loss downward, grab some friends and a sledgehammer, pick a Saturday, and remove the old screed over a crate of beer. Then have new (good) insulation installed under the screed and pour 6–7 cm (2.4–2.8 inches) of new screed on top.

Okay, replacing the screed would have been an option as well. But I think it's off the table due to the costs. In terms of efficiency, underfloor heating would be better, right, or am I mistaken? Because I would have had to replace the radiators anyway, as they are also quite old.

haadaa123 schrieb:

Okay, replacing the screed was also an option. But I think it’s out of the question because of the costs.

It probably wouldn’t make much difference, especially if you do the work yourself.

haadaa123 schrieb:

In terms of efficiency, underfloor heating would be better, or am I mistaken?

Yep, because it requires lower supply temperatures.

haadaa123 schrieb:

Because then I would have had to replace the radiators, since they are already very old.

Another reason to go with underfloor heating. Plus, you gain wall space.