This paper presents a numerical investigation of transient heat transfer in floor heating systems using a specially developed three-dimensional explicit finite-difference model. The study focused on the influence of the cover layer on temperature distribution and on energy consumption. Complete and partial (area) carpets were considered as well as hardwood cover layers over concrete or gypcrete thermal storage. A thick central area carpet over a concrete thermal storage layer (5cm) caused a temperature difference of about 2°C between the carpeted and uncarpeted surface of the floor and a difference of about 11°C in the corresponding regions of the heating panel. The largest thermal lag time between auxiliary heating and floor surface temperature was observed for the carpeted floor (4.75 hours), which also had the highest energy consumption-9% higher than for the case with the uncarpeted 5 cm concrete layer.

Units: SI