Earth tube or ground air heat exchanger is a well established way to achieve passive house ventilation and use the earth as a energy source for both cooling the air in summer and heating it in winter. REHAU’s Ground air heat exchanger has been used in the UK and across the globe to produce some stunning low energy buildings. This online webinar will cover an Introduction to REHAU, How a Ground-air Heat Exchanger (GAHE) works, Requirements for GAHE pipe material, Design / installation criteria, Design software for GAHE and look at some Case studies.