CONCEPT OF DYNAMIC LIQUID FOAM INSULATION FOR GREENHOUSE INSULATION AND THE ASSESSMENT OF ITS ENERGY CONSUMPTION AND AGRONOMIC PERFORMANCES

Energy savings have always been a major concern in the greenhouse industry, particularly for northern tier growers. Better greenhouse insulation delivers an efficient method for energy savings. The injection of dynamic liquid foam insulation between two greenhouse membranes is a technology leading to significant increase in greenhouse insulation. The objective of this paper is to demonstrate the feasibility of this technology in a pre-commercialisation environment and to present its performances in energy savings and plant growth. Laboratory testing has demonstrated that the foam produces an increasing insulation factor which is proportional to the thickness of the foam injected between the two membranes. Results recorded during the winter season include comparative studies of climate conditions and energy savings of the prototype and non-retrofitted greenhouse. Within a full season of production, it would be possible to confirm the technical feasibility of injecting and circulating liquid foam between two greenhouse film membranes. Energy savings results predicted in laboratory conditions and scientific models are confirmed by this experiment in pre-commercialisation settings. Current data, collected in winter season, suggest energy savings of over 50%. Also, the impact of the use of such technology on plant growth would be obtained with a plantation of Tomato (Lycopersicum esculentum).