Energy analysis by simulating the geometry and climatic parameters of a miniature rose greenhouse in TRNSYS and validation with measured data

Energy costs for greenhouses are one of the most important challenges for crop production in such environments. Predicting the thermal needs of a greenhouse is essential to improve its thermal performance, and achieving an optimal solution for predicting thermal behavior and energy management is very complex. In this study, a real rose greenhouse model in Pakdasht city was simulated using TRNSYS software. In this model, the greenhouse geometry as well as the ventilation, cooling, and heating systems were simulated according to their real counterparts. During a month, the temperature and relative humidity inside the greenhouse were measured using sensors installed at different points in the greenhouse. The simulated data were compared with the measured data collected each month. The difference between the simulation results and the measured data was calculated using the following criteria: root mean square error (RMSE), coefficient of variation of root mean square error (CV RMSE), and normalized mean bias error (NMBE). The temperature error inside the greenhouse was 3.5 °C and 12% for relative humidity. Using greenhouse simulation, the greenhouse energy balance was calculated for each month over a year, which showed that the largest energy losses in the greenhouse were related to the ventilation system and heat transfer through its walls. In addition, the orientation of the greenhouse played a significant role in its thermal performance, with orientation changing up to 5% of the solar energy received by the walls.