Correction of the thermal power calculation in the lightweight floor heating based on NT VVS127:2001 standard

Abstract

There are many possibilities for determining the thermal power (thermal output) of underfloor heating systems. These may be mathematical, experimental, and numerical methods. Some of them are described in standards, manufacturers’ guides (e.g. charts or tables based on experimental research), as well as programs with numerical calculations. This article concerns the issue of correct calculation of the thermal power only in lightweight underfloor heating without any screeds. It considers the correct entry of the formula for calculating heat power given in the Norwegian standard NT VVS127:2001, relating to a lightweight floor system with metal lamellas. According to the author of this article, there is a significant error in one of the formulas of this standard, which leads to an incorrect final result. This view was based on the results of the author’s calculations and the calculations and conclusions of other scientists. The correction of the incorrectly written formula of the NT VVS127:2001 standard confirms the correctness of the thermal power calculations in a lightweight underfloor heating system with metal lamellas without screeds.