Dynamic energy analysis of rooftop Greenhouse–Integrated building according to cooling scenarios of rooftop greenhouses for energy saving

Rooftop greenhouses (RTGs) can mitigate the increasing building energy of the abnormal climate and continuing urbanisation. When the external temperature is low, the heating energy consumption of the building’s top floor can be reduced due to the thermal insulation effect provided by the RTG. However, the cooling operation requires elaborate efforts to reduce the total energy consumption of the building and RTG. Thus, according to the cooling scenario of the greenhouse, energy savings of model featuring RTG-structurally integrated building are compared with those of a separately located greenhouse and building. To this end, the validated greenhouse model is employed to analyse the scenario for the lowest energy consumption. The heat pump capacity to maintain the structurally separate greenhouse under optimal crop-growing conditions is simulated based on the energy consumption of the heat pump. Consequently, operating a rooftop greenhouse with forced ventilation during the summer results in an annual energy savings of 44.9% for the top floor of an adjacent building. By suspending crop cultivation during the hot season, building energy consumption can be reduced by up to 60.2% annually. By effectively operating the RTG, the total energy required by greenhouses and buildings can be saved and carbon emissions can be reduced.