ABSTRACT
This article concerns the heat flow into the ground from a slab-on-ground structure with a low temperature floor heating. The performed long-term field measurements indicate, that the built-up of the thermal balance between a heated slab-on-ground and subsoil takes place within a year after the completion of the structure and the beginning of the first heating season. It usually takes the first heating season and the following summer to achieve this, as the fill layers next to the external wall lines are strongly effected by the outdoor temperature changes and the balance is possible to achieve only after the fill layers near the footing wall are warmed up in late summer. During this period the heat loss may be significantly higher than later. Therefore the measurements concerning the heat loss should be performed after this thermal balance is achieved, at the earliest one year after the completion of the building.
