Performance Potential of Flat Plate Solar Air Heaters in Tehran

Abstract

Flat plate solar collectors are very efficient and economic devices to be used for space heating in places with abundant supply of solar radiation. In this paper the results of a parametric study on using solar air heaters in Tehran is presented. Simulations were performed for a typical small building by writing a computer program in FORTRAN. It IS found that as the mass flow rate of air decreases the outlet temperature increases in the expense of decreasing efficiency. On the other hand, as the air channel depth is changed between 12 mm and 24 mm the useful energy gain is almost unaltered. Moreover, the simulation program is extended to evaluate the performance of solar air heaters on a typical winter day under the climatic condition of Tehran, where solar heating collectors are barely used. It is found that, from the energy point of view, for a model building of 157 m(2) total floor area, solar air collectors of 60 m(2), with tilt angle of 35 degrees, can effectively meet the space heating demand during the day, reducing CO(2) emission by 8 tons annually.