Abstract
In the present study both experimental measurements and calculation models have been used to investigate the practical performance of reflective foils in air filled floor cavities. The laboratory measurements were performed in a pivotal guarded hot-box. Both heat flow down through the floor area and the temperature distribution in the cavities were measured. The number of reflective foils and the amount of edge insulation at the edge beams has been varied as well as the environmental temperature conditions. Measured and calculated results show good agreement for most of the tested timber floor variants.