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 a particular 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. This technique utilises temperature difference between outside and underground earth temperature to achieve heating or cooling. This system utilizes minimal active energy to achieve heating or cooling. Temperature below 6 to 7 feet of earth is always cooler or warmer than ambient temperature. When the outside temperature is passed through an underground tunnel it loses its temperature and outcoming air is much cooler than entering the air.

UEDC have expertise in designing and planning of EAT and have explored for many projects successfully.