The main objective of this study was to control the environment inside a room to grow barley during the summer using renewable energy (solar energy). The sub main objectives of this study are application of using solar energy in one of the agricultural sectors to avoid impact of climate change, high energy prices and food availability by creating internal conditions in a thermally insulated room cooled by evaporative cooling, raising the efficiency of the renewable energy consumed to achieve the highest cooling efficiency inside a thermally insulated room to produce cultured barley as an alternative to fodder and Providing freshwater by using seawater in the evaporative cooling process. This study was conducted in the Agricultural Engineering and Biosystems Department, Faculty of Agriculture, Shebin El Kom, Menoufia University, Egypt during of the year 2023 from August to October. To achieve this objective, a polyurethane sandwich room was designed with an evaporative cooling system used to reduce thermal loads to save the conditions for barley germination. A mathematical model was designed to predict the factors affecting evaporative cooling. The effect of different air velocities at different water flow rates was studied on indoor air temperature by the mathematical Model under climatic parameters and using silica gel to reduce air humidity. The system was operated using new and renewable energy (solar energy) under the optimal conditions of the mathematical model and the experimental study. The cold exhaust air was used to cool the solar panels and decrease the loss in their efficiency. The effect of using seawater in the evaporative cooling process on the indoor air temperature and cooling efficiency was studied