Effects of thermal bridges on the heat demand of residential buildings

Abstract

This paper presents the influence of the thermal bridges effect on heating demand in residential buildings using numerical simulation. Quantitative evaluation on temperature field is performed by means of linear heat transfer coefficient. Specific details of existing thermal bridges within the building envelope have been identified and selected for analysis. The model simulation was performed using COMSOL Multiphysics software. Thermo-physical properties of the building envelope elements were selected from the software database and the boundary conditions have been setup. Meshing was done by dividing the virtual domain into an optimum number of finite elements. Model validation was done by comparative analysis between the values of the linear thermal transmittance obtained through numerical simulation and the reference values stipulated in C107-3-2005 technical regulation (catalogue of building thermal bridges). Specific solutions for correcting the thermal coupling between different building envelope elements were adopted in order to reduce the linear thermal transmittance up to 23% and the heat flow rate up to 71%. The evaluation of space heating demand shows the impact of correct treatment of thermal bridges on the reduction of energy consumption.