Cold bridging at corners: Surface temperature and condensation risk

This paper describes theoretical modeling and experimental measurements of the wall temperatures in the corners of buildings. A dimensionless cold bridge temperature (DCBT) is proposed as a parameter to characterise cold bridges. A simple resistance model is suggested as an improved method for calculating cold bridge temperatures in corners. This model shows reasonable agreement with both finite-element modeling and measured data. Theoretical studies suggest that an increased internal surface resistance at the corner results in a substantial increase in cold bridging. During transient conditions the DCBT can vary by 50%. The impact of external corners on the risk of mould growth is discussed. Mean internal relative humidities lower than the normally accepted value of 70% are suggested for rooms with significant cold bridges.