Solar energy utilization by a greenhouse: General relations

Most of solar radiation incident on a greenhouse is absorbed by greenhouse components (i.e., the cover, humid air, plants and soil) and the remaining portion is lost to outside the greenhouse. It is essential to know the absorbed and lost energy terms for any thermal analysis of greenhouses. Existing greenhouse thermal models use the radiative properties of the greenhouse components to directly determine the absorbed energy terms. However, these models neglect the lost energy term and neglect the effects of the multiple reflections of solar radiation between the greenhouse components.