Carpet in the bedroom despite underfloor heating?

Yvonne, it is a Vorwerk carpet and yes, it is approved for underfloor heating. The Lambda value is specified as less than or equal to 0.17 m² K/W.

I have read that carpets up to 0.2 m² are approved, but 0.15 or below is recommended.

The base material is 100% PES (polyester fleece), the construction is specified as 1/10 tufted soft-frisé – whatever that is.

The total thickness of the carpet is 9.5mm – we would glue it, for example, with Wakol adhesive Spaltex, which has a "zipper" effect. This supposedly makes the carpet much easier to remove later.

So it is not as high as a classic high-pile carpet. But it is somewhat higher than, for example, short-pile carpets with 8mm (e.g., Vorwerk Bolero), which unfortunately just don't appeal to us visually.

I am just wondering whether the data in the datasheet regarding the thermal transmittance value applies to installation or bonding. That is a significant difference. Next to it says: Suitable for installation on warm water underfloor heating - that would mean to me that the value refers to installation only, bonding not included. For bonding, the value would have to be significantly better.

R-value is 0.17... Lambda probably not, right?

Yes, correct, R-value sorry.

I see no problem with 9mm.
By the way, we also have Flor on the upper floor, it’s nice and cozy on the feet

Regards

Lambda is then at 0.054 - 34% loss remains (e.g. 20 W/m² instead of 31 W/m² at 30 °C supply temperature, 15 cm installation spacing and 40 mm coverage)