Greenhouses where the production is carried out and optimum environmental conditions achieved according to many plant species are the agricultural structures. Degree-hour or degree-day methods can be used to get knowledge about energy requirements of any buildings. These methods can provide information about on the amount of energy by using measured and meteorological values and obtaining the heating and cooling values of buildings. The study was chosen in the Kumluca district of Antalya, the place where the most intensive of greenhouse cultivation was made in our country. Autumn cultivation is being done for the pepper plant. This study was conducted between October 2015 and June 2016 in plastic greenhouse. The temperature inside the greenhouse values were recorded during the growing period of the pepper plant. The obtained values were analyzed by Student-t test. The regression coefficients were obtained by calculating the prediction equations between the basic temperature values and the heating and cooling degree-hour values. These coefficients are found between 0.997 and 0.999 for heating degrees-hours and between 0.982 and 0.997 for cooling degrees. As a result, efficiency and quality can be increased through air conditioning improvements in the greenhouses located in mild climate areas such as Antalya, where heating is maintained for frost protection and ventilation difficulties are experienced.