Benefits of using variable frequency drives on greenhouse exhaust systems

Abstract

Greenhouses provide many benefits to a plant producer by allowing for a tightly controlled environment best suited for the crop. Since sunlight is allowed almost free access to the inside of a greenhouse, removing heat buildup becomes a large obstacle to deal with. Energy needed to meet a typical cooling requirement can be costly and lowering overhead will be helpful to a sustainable greenhouse business. Variable frequency drive (VFD) technology has the potential to not only save electricity and reduce monthly operating costs, but can offer the grower climactic and water use benefits as well. Two greenhouses were compared for this study, one having a typical On/Off style fan system and the other has a VFD system installed. The parameters looked at were short cycling, total energy use, temperature, crop growth, and water use. The results of the research indicate that VFDs do offer significant reduction in electricity usage, showing only half of what the On/Off fans used. A reduction in water use was also seen with slightly greater crop growth in the VFD greenhouse. VFDs on exhaust fans show benefits that any greenhouse grower would like to have in their operation.