Which impact sound insulation is suitable for underfloor heating?

Thank you for the explanation!

Best regards
Sabine

I already mentioned in another thread:
The heat stays inside the house, there are no losses - no matter what kind of impact sound insulation is installed.
UNDER the parquet, there is definitely a much thicker insulation. Before the heat escapes there, it passes through even the thickest impact sound insulation a hundred times over. In the upper floor it doesn't matter anyway, since the heat at most can only go down to the ground floor.
Therefore, I bet that you won't notice different impact sound insulations (yes, even glued or floating) on the heating bill.

The heat stays inside the house, there are no losses

To bring a constant heat flow from the heating pipes into the room, the resistance of the floor structure must be overcome. If the resistance is high, the driving temperature difference must compensate for this and become greater. That means the "heat" in kW remains the same, you are right about that, but the heating system's flow temperature must be higher. Depending on the system, you may notice this (less so with gas, more so with heat pumps). It may be marginal (domestic hot water also plays a role), but the effect is greater than zero.

The heat stays inside the house, there are no losses – no matter what kind of impact sound insulation is installed.

Hello, that is physically incorrect. Energy is indeed conserved in some form (law of conservation of energy in thermodynamics), but that is not really the point here. Following your argument, exterior wall insulation would also be pointless. If that were the case, you would only need to heat your living room once (and even a simple tealight would suffice...) and then you would have cozy warmth all winter because nothing is lost??

Therefore, I’d bet any amount that you won’t notice different types of impact sound insulation (even glued or floating) on your heating bill.

Of course, there is a difference! For example: You put a pot of water on the stove (equivalent to our glued installation) to bring the water to a boil. This requires a certain amount of energy. If your statement were true, you could do the following on the stove: place a trivet (equivalent to our parquet underlay) between the stove plate and the pot! Would the water still boil with the same energy input? I don’t think so...

Following your argument, exterior wall insulation would also be pointless.

No. My argument (very thick insulation on one side, very thin on the other) certainly cannot be interpreted that way.

Of course, there is a difference!

Yep. But as said, an almost immeasurably small one.

As an example: You place a pot with water on the stove (corresponding to our bonding) to bring the water to a boil. This requires a certain amount of energy. If your statement were true, one could now do the following on the stove: place a pot coaster (corresponding to our parquet underlay) between the hotplate and the pot! Would the water continue to boil with the same energy input? I don't think so...

If it is ensured that the heat cannot go anywhere else, what else can the water do?

If it is ensured that the heat cannot go anywhere else, what choice does the water have?

Let us imagine that the hotplate is heated by water flowing through it. The water enters the hotplate with a supply temperature and exits again with a return temperature. The difference (times the mass flow rate times the specific heat capacity) corresponds to the transferred energy. Using a coaster as an insulator between the hotplate and the pot would cause the return temperature to be higher, and the supplied energy decreases. The water at the top of the pot would no longer boil. Countermeasure: Increase the supply temperature.