Use of buried pipes for energy conservation in cooling of agricultural greenhouses

Earth-to-air heat exchangers can be used for energy conservation in cooling of agricultural greenhouses. A parametric analysis performed for a typical glass greenhouses illustrates the effect of pipe length, pipe diameter, and air velocity inside the pipes on the performance of the system. Measured data of indoor air temperature collected from a 1000 m{sup 2} fiberglass covered greenhouse, equipped with four buried pipes, are compared with calculated data and are found to be in very good agreement. 26 refs., 6 figs., 1 tab.