Thermal bridge effect of air gaps in wall construction

The paper presents the phenomenon of thermal bridges caused by air infiltration. The problem of poor air tightness is very common in the former Eastern Bloc countries. The laboratory investigation was set up to recognize the impact of air infiltration on heat flux through the building envelope. The frame wall model insulated with loose mineral wool was investigated in non-isothermal climatic chamber. As a result of cold air infiltration, surfaces of gaps and areas adjacent to them were cooled, which is illustrated on temperature profiles. The forty minutes infiltration of 0o C air resulted as a 3.5o C cooling of gap area. The thermal simulation in Delphin confirmed the laboratory results.