Super Efficient Greenhouse Design

Building envelopes which require high light transmissions, such as greenhouses, need a highly dynamic system to provide shading at peak loads when solar radiation levels are too high, and also provide thermal insulation at night when the surrounding temperature is lower than required for optimal plant conditions. Removable liquid foam within a transparent double layer is presented in this paper, which enables rapid shading and night-time insulation without compromising available light when these are not required. Heat transfer through the foam was measured in a testing rig with 3 different bubble diameters and 2 different foam depths, and a model developed to begin to explain the foams effect on the convection forces within the cavity. Numerous chemical formulas were tested to produce a foam that could remain in place for more than 2 hours. Experiments to ascertain the effect of the foam material on conductive heat transfer within the cavity were conducted, and the results demonstrated this to be negligible. These initial experimental results are valuable for this novel dynamic system design.