Thermal energy use in greenhouses

摘要: In the North European greenhouses, energy use for climatization accounts a significant share of operational costs. Air temperature and humidity are important factors whose control is crucial assuring high productivity limited energy. The objective this thesis was to examine thermal in greenhouses investigate impact number climate parameters on that use. A specific goal compare measured heating with values simulated employing model developed Powersim software and, by means model, determine amount necessary dehumidification tomato greenhouse. Another employ experimentally obtained performance rotary heat exchanger estimate potential savings when used Indoor outdoor data were collected three located southern Sweden, two tomatoes one ornamental plants. greenhouse first then modelled different levels transpiration, i.e. leaf index area (LAI) 3.5 4.0 m²/m². wind under no-sunlight conditions at temperatures investigated. operating tested series measurements. study showed significantly higher than Further, increased together speed. reduction speed 50% could result 4-10%. as simulations fairly similar values, especially modelling transpiration levels. However, it concluded further work needed. indicated 23-29% purposes. It shown moisture efficiencies employed about 70% 45%, respectively. found usage such investigated resulted 15-17%.