Replacing floor heating with underfloor heating - is it sensible?

Hello everyone,

we are moving into our own home on 01.02.19. As part of the renovation/ refurbishment, we want to tear out and renew all the floors.
Since the floor is going to be removed, I am now wondering whether it makes sense to mill in underfloor heating into the screed. The existing heating, like the house, is from 1989. The area to be renovated is 100m².

(The heating to be installed on the existing floor is not desired, as the kitchen would become even lower, and I also assume there would be problems with the windows and the front door).

Does the change even make sense, as the floor heating is already quite old after all?

What about the kitchen? Do I have to dismantle the kitchen or is it enough if the heating pipes are laid along the cabinets?

What costs should I expect? An existing offer amounts to about €3200 for milling and connection. Are there further costs to be planned here?

I hope for some advice and opinions.

Thanks in advance!!

In southern countries, where people are not as meticulous as the Germans, the covering in front of the kitchen cabinets is omitted. I am already horrified at the thought ... What is supposed to be underfloor heating? Whether it works or not depends on several boundary conditions, which a heating engineer or planner should first examine.

The question for me is rather whether it makes sense. Since the underfloor heating supply temperature is much more efficient than an FBE, that's what matters to me. If it makes little sense, I'll save the money and the time.

What do you mean when you say it horrifies you at the thought? What problems do you think could occur? Mold?

In an FBE, the return flow of the radiators, like in underfloor heating, is laid in the floor and thus heats with the residual heat.

The underfloor heating is completely laid under the floor, runs with lower energy, and works without radiators. (I hope my explanation is somewhat adequate)

What speaks against removing the radiators and using the existing pipes with the appropriate temperature?

Depending on what else is being renovated (windows, exterior wall, floor ceiling, basement ceiling), the heating demand should also decrease, so that the remaining heating surface in the floor is sufficient. It would be good to have planning documents for this.

You should definitely dismantle the kitchen. First to remove the covering and also because otherwise you will never get the dust from milling out of there.

But is it really sensible in terms of effort and cost? I also think it is possible, just at what price.

So you won’t save money with underfloor heating compared to heating. If you have a gas condensing boiler, the efficiency depends on the return temperature reaching the system (only with heat pumps does the flow temperature play a significant role).

With radiators, under design conditions, i.e. at -10°C in Aurich, you probably (!) have heating water temperatures of 50-60°C in the flow and 30-50°C in the return (delta T of 20K). The downstream return pipe through the floor lowers the return temperature again by 5-10K. This way, you also have good condensing utilization on cold days. With pure underfloor heating without radiators, the heating efficiency will not increase further.

So if the radiators don’t get in your way – keep them and enjoy warm feet anyway. If they are bothersome, ask a competent [TGA planner] about the heating loads and capacities whether it can be realized without radiators via the existing pipes. The costs for this should be about 10 times lower than for new pipes, where the screed is also milled 2 cm thinner.