Earth-Air Heat Exchanger for Room Heating and Cooling : A Review

Air pollution occurring by burning of coal in power plants and releasing of harmful CFCs in atmosphere contributes to major extent in polluting earth atmosphere. The use of renewable energy sources improves the thermal conditions of rooms. There is a rising interest in heating and cooling systems based on renewable energy sources. Air heating or cooling with Earth-Air Heat Exchangers (EAHE) is one approach for reducing ventilation heat losses and improving thermal comfort in buildings. This device can be used to maintain comfortable thermal conditions inside the room, hence reducing power consumption of Air Conditioning units. The Earth-Air Heat Exchanger (EAHE) device consists of a buried pipe through which external ambient air is passed. The flowing air exchanges heat with surrounding soil and leaves the device with a temperature less than or more than compared to its input temperature. The results obtained will be investigated. The earth temperature from a depth of 1.5-2 metres remains constant. Hence, Earth-Air Heat Exchanger tubes will be buried at or more than this depth to get proper comfortable conditions for a room. Two pipes made of different materials will be used for comparative study.