Determination of heat transfer coefficients for a greenhouse designed to use waste heat

The thermal properties of the porous concrete floor enable it to be used as a primary heat source for the greenhouse. Other advantages such a system has include weed control, the elimination of water puddling on greenhouse floors, and its ability to support light vehicular traffic, making this type of floor an attractive option for using power plant waste heat. The vertical curtain heat exchangers have been shown to be extremely effective for distributing heat to the greenhouse from low-temperature water. The CELdek evaporative pads performed with a minimum of problems and proved to be adequate at cooling both water and warm air. Although the warm flowing through the pads was at times heavily silted, relatively little fouling of the pads occurred, and over a 6-month period of continuous use no change in performance was noticed. During extremely cold weather, the area around the cooling system air intake accumulated considerable amounts of ice which restricted the air flow. However the water running through the CELdek continued to be cooled. The design of the shed housing the evaporative cooling system does not appear to be ideal and may have contributed to nonuniform flow through the pads, and restriction of air flow.