This study aimed to compare the efficiency of some alternative pad materials found in Brazil, such as the "cinasita" (an expanded clay), the sawdust, the vegetable fiber and coal. The experiment conducted in summer conditions, in greenhouses located in the Federal University of Viçosa, Minas Gerais. The comfort thermal atmosphere was evaluated through the Black Globe Humidity Index (BGHI) and Relative Humidity (RH), measured daily, every two hours, between 8 to 18 h. The obtained results were interpreted through the variance analysis. On the basis of this study, it is possible to infer that the making of pad for evaporative cooling systems, using the material cinasita and vegetable coal, it indicates advantages compared to other studied materials. However, as there were no significant differences in every schedule, for the tested materials on the basis of results of relative humidity of the air and BGHI. It suggests of new investigations, for the determination of correct thickness of the pad, keeping in view the correct obtaining of the static pressure of the system, as this being a decisive factor, in what refers to its efficiency.
evaporative cooling systems; pad material; thermal comfort
