Determination of some technical parameters used for air conditioning of greenhouses in three different climate zones in Turkey

Greenhouses offer viable solutions for year-round agricultural production at locations with inconvenient climates, or scarce resources and land. Understanding the botanical requirements for plant growth may result in the creation of control strategies aiming to gain produce that is competitive and affordable. This study's main objective is to determine the required parameters of climatization in sophisticated greenhouses that will be built in different regions of Turkey, according to TS 825 standards. With the help of the programs developed in the study, calculations, which are based on psychometric equivalents, were made and parameters regarding ventilation, cooling, and heating of greenhouses were calculated. During cold seasons, to maintain a minimum of 16/20°C temperature, the first, second, and third areas require 65 – 95 W m-2, 100 – 110 W m-2, and 160 – 180 W m-2 heating power, respectively. Due to increasing energy prices, heated greenhouses must be insulated accordingly. Well-insulated thermal screens in greenhouses conserve energy while saving heat near the levels given by screen manufacturers, whereas badly insulated screens save heat as low as %9. Additionally, an inspection of daily temperatures within greenhouses and the total temperature in regions with temperate climates enable saving energy. The cheapest climatization precaution within greenhouses during hot seasons is natural ventilation. For sufficient ventilation of the greenhouse, an opening of %24 of the floor area on the surface of the roof is enough. Nevertheless, if there are insect nets within the greenhouse this opening will not be enough. In a greenhouse with insect nets, ventilation opening should be %40 of the floor area. Also, with ventilation, shading is an effective tool for regulating temperatures in greenhouses. In situations where the outside temperature exceeds 27°C, evaporative cooling is required within greenhouses. The efficiency of evaporative cooling differs according to the system used and outside humidity. According to TS 825 standards in the first area, it has been determined in the study conducted that due to high humidity, evaporative cooling does not meet the required parameters of the environment necessary for plant growth. In Şanlıurfa, which is in the second area, fan-ped systems within greenhouses are efficient in hot seasons due to low humidity. In the third area, due to moderate outside temperatures, fogging at short intervals is sufficient to maintain production within greenhouses. Keywords: Greenhouse, Heating, Ventilation, Cooling