Effect of Thermal Bridges on the Heat Balance of Buildings

Abstract

Thermal bridges in the thermal insulation of envelopes occur in all forms of building construction and should be minimised to reduce local heat losses. This paper presents the effect of thermal bridges on the comfort of the habitat within a building. Indeed, the thermal bridges increase the heat losses of a building and thus the consumption of heating. Thermal bridges cause additional heat losses compared to losses through the walls of the building. These losses can exceed for some 40% of the total heat losses through the envelope. An example of an energetic effect of a thermal bridge has been presented. For this example, the heat losses on a floor height and per meter of facade were calculated. The results showed that from 5 cm thickness of insulation, the difference between the loss curve in the absence of thermal bridge, and the loss curve taking into account the thermal bridge is almost independent of the thickness of the insulating. Another example was also presented to demonstrate the effect on thermal bridging when increasing the levels of insulation to a normal corner. The results showed that for a 50% and 100% increase in the thickness of the insulation, the U-value, linear heat loss coefficient ? and surface temperature factor fRsi were considerably decreased.