HEATING AND COOLING POTENTIAL OF AN UNDERGROUND AIR-PIPE SYSTEM

The annual heating and cooling potential of an underground air-pipe sy stem has been evaluated in terms of dimensionless parameters of the sy stem. The effect of diurnal and annual variations of environmental par ameters (solar radiation, ambient temperature and relative humidity) h as been considered. The results are obtained for hot-dry, cold-dry and composite climatic conditions typified by the Jodhpur, Leh and Delhi climates respectively. The effect of suitable earth surface treatments on the thermal performances of the air-pipe system has also been anal ysed. For wet-shaded earth surface the cooling potential of a pipe of length 50 m and radius 10 cm at a depth 6 m in Jodhpur climate is foun d to be 4472 kW h, while for the Leh climate under glazed and blackene d earth surface conditions the heating potential of such an air-pipe s ystem is found to be 9097 kW h.