Earth-to-air heat exchangers for passive houses located in South-Eastern European countries

Abstract

Earth-to-air heat exchangers (EAHEs) increase the energy performance of passive houses (PHs). The EAHE's performance depends on the climatology of the place and on design and operational parameters. The current commercial practice for implementing EAHEs in the PHs of South-Eastern Europe is by ad litteram importing the existing German design solutions. This is not always a good strategy from the point of view of thermal performance. In this paper, a reference EAHE with fixed design and operational parameters is defined and its performance is studied, when moved in different geographical places in Germany and other Western and South-Eastern European countries. The maximum yearly heating energy for Western Europe is 2730.6 kW h at Stockholm, while in Munich it is 2202.3 kW h. The same quantity in South-Eastern Europe is 2544.4 kW h at Bucharest. The maximum yearly cooling energy in South-Eastern Europe is 973.5 kW h at Belgrade and 739.7 kW h at Bucharest. This quantity is significantly larger than that for Western Europe (149 kW h at Munich). The EAHEs are indeed effective in the climate of South-Eastern Europe, especially as a cooling source during the warm season. Appropriate design solutions and operational parameters are needed in order to obtain the best EAHE's performance. A few practical recommendations for the implementation of EAHEs operating with forced air circulation are given.