Environmental control for Chinese solar greenhouses: A review

Chinese solar greenhouse (CSG), a unique agricultural facility in northern China, offers a way to ensure the overwintering production of fruits and vegetables in high latitude and cold regions. It accumulates solar energy during the day to provide heat for plant growth at night, achieving a temperature difference of over 35 °C between inside and outside the greenhouse. However, the impact of external climate conditions on the microclimate within the greenhouse is not sufficient to meet the needs of crop growth. So, precise control of greenhouse environment is essential to ensure the crop production. Numerous intricate elements, including exterior meteorological conditions, greenhouse structure and covering materials, indoor environmental control systems, and crop cultivation, all have a significant impact on the environment variations occurred inside a greenhouse. Therefore, this paper reviews the efforts of our team and other researchers in environmental control for the CSG such as lighting, heat storage and insulation, ventilation, and cooling in recent years. To precisely and automatically control the greenhouse environment, various environmental monitoring and regulation equipment developed by our team are integrated into the Internet of Things platform. These studies contribute to the high-yield and automated development of facility agriculture in northern China.