Greenhouse with an Integrated NIR Filter and a Solar Cooling System

The scope of this paper is a new greenhouse design that incorporates both a filter for rejecting near infrared radiation (NIR) and a solar cooling system. Cooled greenhouses are an important issue for the combination of high global radiation and high outdoor temperatures. As a first measure, this study prevents heat entering the greenhouse by applying a NIR-reflective cover material. The special spectral selective properties of these materials will block up to 50% of the outside solar energy from entering the greenhouse, which will reduce the cooling capacity required. The second measure is the introduction of a solar driven cooling system. When the NIR reflecting coating is designed as a parabolic or circular shaped reflector integrated in the greenhouse, the reflected solar energy received by a PV cell at the focus delivers sufficient electric energy to drive a fan and pad cooling system. The excess energy can be used for desalination and/or energy supply. Parameters related to typical climate conditions and energy flows are presented