During the current research the effect of greenhouse climate control equipment use on vertical air temperature profile as well as on the fruit temperature and flue gas concentration was studied. It was observed that when significant heat input (radiation) at the top of the crop takes place a vertical temperature gradient exists, with the bottom of the crop being colder than the top. This temperature gradient cannot be reduced by using only the lower vertical air circulation fans but it can be minimized by additional heat input at the bottom; this may result in excess heat that has to be removed (from the top of the greenhouse) through either natural ventilation or with the use of VentilationJets when the screens are deployed. During the studied period about a quarter of the daily gas use for heating took place at the same time when the VentilationJets were removing warm and humid air from the top of the greenhouse. The use of the VentilationJets was also important to prevent supra-optimal humidity levels. It was also found that minimum a ventilation is needed (especially on not windy days) to ensure that concentration of NOx will not rise up to dangerous for the crop levels
There are no comments yet. You can post the first one!
Post a comment
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.