Study on temperature distribution characteristics and winter energy-saving optimization schemes for glass multi-span greenhouses: a case study in Beijing

As a major producer and consumer of vegetables, China has widely adopted multi-span glass greenhouses. However, limitations in their enclosure structures and gable-roof designs have led to significant heat loss during winter and high energy costs. This study selected glass multi-span greenhouses in Beijing as the research subject. Using EnergyPlus software, it conducted simulation analyses of air temperature variations at different locations and seasonal periods within the greenhouses. Based on the temperature distribution characteristics inside the greenhouses, an optimization strategy for dividing the multi-span greenhouse into hot and cold zones was proposed. The research found that implementing this zoning approach could reduce the total heat load per unit area during the most unfavorable winter periods by approximately 49.7%. These findings provide essential technical support and theoretical basis for optimizing the design and energy-efficient operation of multi-span glass greenhouses in northern regions.