References

A satisfied customer about using natural heat:

"The temperature remains constantly between 18,5 - 20,0 degrees in all rooms, day and night, even in the winter time. Due to the consistent allocation trough the floor it is more than enough to feel comfortable. According to my records, our average annual costs per month are about EUR 50,00 for energy (heating and warm water) for 160 m² including celler and attic.

The controlable ventilation was a good investment too, especially in the winter time. I cannot make any statements about the energy savings but ventilating without getting cold feet and "always remembering the windows" is very convenient.