Heat transfer through small, unventilated air cavities in the current standards

The paper discusses in detail the calculation procedures from the PN-EN ISO 10077 and PN-EN ISO 6946 standards used to determine the heat transfer through small, unventilated air cavities. In order to assess the differences in real situations, calculations of an exemplary air cavity were also performed using a computer program implementing these methods. On the basis of the analyzes carried out, a number of differences in procedures and the range of potential discrepancies in the results were demonstrated. Calculations were made for an example air void. The differences in heat fluxes were up to 11% depending on the method used.