Abstract
In the recent time the EAHE is widely used as a passive cooling and heating technique due to the hug thermal potential of earth as and as a result of energy crisis. In the past years many researches published including studying this type of heat exchanger and using it in many applications and many locations with different climate conditions. Also these researches investigated the most affecting parameters. In this paper a review is made to survey the published literature is this filed to shed a light on the research in this subject
