andimann
2016-01-13 18:02:50
- #1
Why should that be?
For the basement floor, sure, no question.
But for the ceiling from ground floor to upper floor? That’s all in the same thermal zone. Air temperature on the ground floor is 20 °C, air temperature on the upper floor is also 20 °C, and the temperature of the ceiling concrete is also 20 °C. You heat the ceiling either way. Either through the underfloor heating from above or through the room heat from below (and thus through the underfloor heating on the ground floor).
Yes, with temperature changes and large temperature differences, the insulation may make a difference. The insulation ensures that you can have a lower temperature on the upper floor than on the ground floor at all. In reality, you will not have differences greater than 2 to 3 °C.
When heating up, it of course ensures that the heat initially goes upwards into the room and thus reacts faster. Ok, understood, I’ll accept that!
But in the medium term, a temperature equilibrium sets in and the concrete of the ceiling will become warm. Simply because it is heated from the floor below. Since warm air rises, the concrete temperature will even be minimally higher than the room temperature below.
I also understand this from when underfloor heating was operated with high supply temperatures. But today it mostly runs at around 30 °C. So only about 10 degrees more than the room temperature.
For that, 30-50 mm insulation should be more than enough?
So what is the point of 120 mm insulation under the screed on the upper floor, as Oleda222 does? That is more than what was used a few years ago as external insulation! And that has to cover temperature differences of up to 40 °C and not just 10 °C.
There must be a reason for that, but I don’t get it right now....
Best regards,
Andreas
Without the insulation, the underfloor heating would not work effectively.
For the basement floor, sure, no question.
But for the ceiling from ground floor to upper floor? That’s all in the same thermal zone. Air temperature on the ground floor is 20 °C, air temperature on the upper floor is also 20 °C, and the temperature of the ceiling concrete is also 20 °C. You heat the ceiling either way. Either through the underfloor heating from above or through the room heat from below (and thus through the underfloor heating on the ground floor).
Yes, with temperature changes and large temperature differences, the insulation may make a difference. The insulation ensures that you can have a lower temperature on the upper floor than on the ground floor at all. In reality, you will not have differences greater than 2 to 3 °C.
When heating up, it of course ensures that the heat initially goes upwards into the room and thus reacts faster. Ok, understood, I’ll accept that!
But in the medium term, a temperature equilibrium sets in and the concrete of the ceiling will become warm. Simply because it is heated from the floor below. Since warm air rises, the concrete temperature will even be minimally higher than the room temperature below.
I also understand this from when underfloor heating was operated with high supply temperatures. But today it mostly runs at around 30 °C. So only about 10 degrees more than the room temperature.
For that, 30-50 mm insulation should be more than enough?
So what is the point of 120 mm insulation under the screed on the upper floor, as Oleda222 does? That is more than what was used a few years ago as external insulation! And that has to cover temperature differences of up to 40 °C and not just 10 °C.
There must be a reason for that, but I don’t get it right now....
Best regards,
Andreas