American-Eurasian J. Agric. & Environ. Sci., 15 (1): 78-84, 2015 ISSN 1818-6769 © IDOSI Publications, 2015 DOI: 10.5829/idosi.aejaes.2015.15.1.12494 Corresponding Author: Egbal Elmsaad, Department of Agricultural Engineering, Faculty of Agricultural Sciences, University of Gezira, Wadmedani, Sudan. E-mail: naser_elamroni@yahoo.co.uk. 78 Evaluating the Effect of New Local Materials of Evaporative Cooling Pads Egbal Elmsaad and Abdelnaser Omran 1 2 Department of Agricultural Engineering, Faculty of Agricultural Sciences, 1 University of Gezira, Wadmedani, Sudan School of Economics, Finance and Banking, College of Business, 2 Universiti Utara Malaysia, 06010, Sintok, Kedah, Malaysia Abstract: The present study aimed to evaluate the feasibility of celdek pads, luffa pads, straw fiber pads and sackcloth pads as alternative pad materials. Experimental measurements were conducted and the experimental data were quantitative. The experimental work mainly focused on the effects of different types and thicknesses of evaporative cooling pads when used for changing the environmental conditions inside greenhouses. Moreover, the experimental work involved the measurement of environmental parameters viz., temperature, relative humidity, air velocity and pressure drops at different times during the day, using the different thickness parameters of the evaporative cooling pads i.e., 50, 100 and 150 mm and the water flow rates through the pads. The data obtained from the experiments and measurements were analyzed using Statistical Package for the Social Sciences Results deciphered that there was a significant difference between evaporative cooling pad types and cooling efficiency. The Luffa pads yielded an average saturation of 73.67%, whereas other pads yielded the following average saturations: straw fiber pads 71.87%, celdek 70.33% and sackcloth 69%. However, there was a highly significant difference between the pad thickness and cooling efficiency. The results obtained for environmental factors, indicated that there was a significant difference between environmental factors and cooling efficiency. In terms of the effect of air velocity on saturation efficiency and pressure drop, higher air velocity decreases saturation efficiency and increases pressure drop across the wetted pad. Finally, the present study indicated that the luffa pads perform better than the other evaporative cooling pads and have higher potential as wetted-pad material. Key words:Greenhouses Temperature and humidity Heating and ventilation Greenhouse technology Greenhouse applications INTRODUCTION such as carbon dioxide, temperature, relative humidity, A greenhouse is a structure used for protecting possibility for the off-season production of many crops plants from adverse climatic effects and for supplying [2]. The increase in air temperature inside a greenhouse a favorable environment for plant production. with a prevailing high outdoor air temperature in the This technique is necessary to overcome the high hazards tropics will stress the greenhouse crops [3]. Thus, of open field production, such as high rainfall, inters solar lowering the air temperature is a major concern for tropical radiation, weed rivalry, as well as damages caused by greenhouse climate management. During the hot season, diseases, insects, high temperature and relative humidity the temperature of ambient air inside greenhouses and [1]. Therefore, in such regions, the reduction of air animal houses increases to over 40°C because of thermal temperature inside a greenhouse or the regulation of the stress [4]. In greenhouses, thermal stress negatively temperature closer to the ambient temperature during affects the emergence, stem strength, flowering and fruit summer is necessary for successful crop production. set and sizes of seedlings. High air temperatures in animal The growth conditions in a greenhouse system are houses decreases feed consumption, weight gain and usually achieved by monitoring effective growth factors, milk and egg yields of animals [5]. In several countries, light and radiation. Greenhouses offer a better