Cooling greenhouses in the Arabian Peninsula

Cooling greenhouses in the Arabian Peninsula is very crucial to extend the growing season. This poster presentation reviews modification and inclusion of greenhouse cooling through optimization of the most commonly used evaporative cooling system in the region. In Kuwait, researchers conducted a study on four identical greenhouses, each equipped with different cooling systems: two positive pressure cooling systems, with fans respectively located at the top and at the bottom of the cooling chamber and two negative cooling systems, with air entry inlet respectively located at the top and at the bottom of the cooling chamber. In United Arab Emirates the evaporative-cooled greenhouses were equipped with desiccant pads for the purpose of removing the water vapor from the incoming air streams. In these greenhouses solar energy was used to regenerate desiccant solution and maintain their desiccant properties. In Oman, researchers used sea water, instead of scarce freshwater for operating the cooling systems. They were able to reduce the consumption of freshwater to zero compared to the classical cooling systems, for which the consumption of water represents about 2/3 of the total freshwater used in greenhouse production. In Bahrain, researchers came up with an oval-shape greenhouse enabling them to increase the cooling efficiency by reducing the air relative humidity before it passes over the cooling pads. These studies gave positive results with respect to water consumption, profitability, and growing season extension. But they also concluded that additional research is required to determine an optimal configuration of a greenhouse to meet climatic conditions of the Arabian Peninsula.