Fan and Pad Greenhouse Evaporative Cooling Systems

Abstract

In Florida, greenhouse temperatures can easily exceed 100°F during the summer if they are not equipped with active cooling systems. Such high temperatures reduce crop quality and worker productivity. Evaporative cooling is the most common method for reducing the temperature inside a greenhouse, but it has limitations in our hot, humid climate. Air conditioning or refrigeration systems can be used, but their installation and operating costs are usually prohibitive. This 6-page fact sheet is a minor revision written by J. A. Watson, C. Gómez, R. A. Bucklin, J. D. Leary, and D. B. McConnell, and published by the Department of Agricultural and Biological Engineering, September 2019. CIR1135/AE069: Fan and Pad Greenhouse Evaporative Cooling Systems (ufl.edu)

Development and Application of a Mathematical Simulation Model to Evaluate Environmental Performance of Greenhouses Using Physical and Climatic Indicators

“…The much better performance of both Abu Halima and Date Palm sites could be attributed to the well-designed properly installed and operated evaporative cooing system. These results are in line with the finding of [21] and [19].…”

“…Where: R hap = The relative humidity at pads, R hac = the relative humidity at center of greenhouse, R han = the relative humidity at the end of greenhouse 3. Cooling efficiency (Cf %): this is defined as the ratio of the actual dry bulb temperature reduction to the theoretical maximum at 100% saturation [19]. It is calculated as per the following equation:…”

“…From figure 4 it is clear that in the Date Palm Co site and Khartoum university site are lower than the target rate while that maintained in Abu Halima is equivalent to the standard level. [15] Stated that ventilation rate depends on airflow velocity through cooling Pads (material and maintenance from clogging), fans capacity, horizontal location distance of fans and cooling pads.…”

“…While the status of Energy efficiency is to be indicated through Cooling effectiveness, and House ventilation rate with standard values of 70%, and 0.9 respectively. However, it is planned that prediction of system overall efficiency with minimum standard value of 75% indicates acceptable overall system performance [3,7,12,11,13,15]. This architectural evaluation research study is conducted in pursuit of simulating conditions to reflect the reality of fan and pad greenhouse design.…”

Shertered horticulure adapted to different climate zones in Radhort Countries

“…Th e diurnal relatively high air temperatures combined with the absence, practically, of rainfall lead to diurnal values of air relative humidity no greater than 30-40%. Consequently, a satisfactory performance of an evaporative cooling system is assured for a greenhouse installed in such an area (Watson et al, 2019). However, this requires additional investment for more sophisticated technical options like fan and pad cooling, or a high-pressure fog system, both of which also improve the hygrometric status of the greenhouse environment.…”