ISHS Acta Horticulturae 719: International Symposium on Greenhouse Cooling
GREENHOUSE COOLING BY NIR-REFLECTION |
| Authors: | S. Hemming, F. Kempkes, N. van der Braak, T. Dueck, N. Marissen |
| Keywords: | near infrared radiation, spectral filter, greenhouse covering, plastic films, coatings, greenhouse climate, climate model |
| Abstract:
Wageningen UR investigated the potential of several NIR-filtering methods to be applied in horticulture. In this paper the analysis of the optical properties of available NIR-filtering materials is given including a calculation method to quantify the energy reduction under these materials and to estimate the contribution for greenhouse cooling. It can be concluded that the optimum NIR-filtering material is still not found but there is good potential for further developments. NIR-filtering multilayer coatings applied to plastic film or glass filter out NIR most effectively. NIR-filtering is not desirable during winter-time in most climatic regions. Therefore, NIR-filtering coverings should not be used in unheated greenhouses since they cause an undesirable temperature drop. NIR-filtering white washes still reduce PAR too much. NIR-filtering (moveable) screens could be an alternative in the future. Future studies should also investigate whether it is possible to use the reflected NIR energy for other processes or cost-effectively storage. | |
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