Earth air tunnel or earth air heat exchanger is a pre-cooling or pre-heating system which consists of a pipe or network of pipes buried at reasonable depth below the ground surface. It either cools the air by rejecting heat to the ground or heats the air absorbing heat from the ground. It utilizes the fact that the deep earth temperature remains almost same as the annual average mean air temperature of the location.
BEEP worked with Dr Pierre Hollmuller of the University of Geneva, who is an international expert in this domain, to analyse the performance of a large EAT system in North India. BEEP also conducted a training programme for engineers and architects on design of EAT systems. A design and dimensioning tool for EATs was also made available during the training.