This research aims to study the use of the closed system of air through earth tubes for cooling greenhouses. This had been achieved by a field study using plastic earth tubes under the dry and hot climatic conditions of the region under study. An elliptical or semi-circular shaped greenhouse and its accessories were constructed according to the appropriate engineering specifications of the experiment site. Results showed that the closed systems of air through plastic earth tubes can not be used independently for cooling the greenhouse in order to attain the suitable temperature for plant growth but can be used in reducing energy consumption. The performance of the cooling system was capable to reduce temperatures during winter season from 79.4°C-68.6°C i.e. by a magnitude of 10.8°C. Also the system can be used independently during autumn and spring seasons in case of temperate conditions. The study recommends the development of the greenhouse design by burying the earth tubes beneath the house in order to utilize the space, reduce the numbers of tubes and heat loss.