Throughout history, humans have always sought convenience. One such amenity is providing conditioned air in the hot seasons. Evaporative coolers and split air conditioners carry out this task in houses. In arid and semi-arid climates such as Isfahan, Yazd, and Kerman the lack of humidity adds to the discomfort of the summer heat; therefore, evaporative coolers are superior to split air conditioners into these areas. Water consumption is a significant factor in the functioning of evaporative coolers. Located in the Middle East, Iran faces water shortages throughout the year, which becomes critical in summers. The reasonable price of evaporative coolers and the dry air has made evaporative coolers a popular choice in most regions of Iran; thus, the chief factors in choosing these coolers are their cooling power and water consumption. Unlike split air conditioners, the cooling power of evaporative coolers is related to the incoming air temperature and humidity of the cooler location. There is a label on evaporative coolers indicating the cooling power of the device at a given temperature, which can be different from the cooling power of the actual cooler location. In this thesis, inside laboratory conditions that allowed the control of the incoming air temperature, the relationships between air velocity, incoming air temperature, cooling power, and water consumption were calculated. In this study, various flow rates were flown through straw pads; moreover, the air-cooling degree and its relation with the incoming airflow in various temperatures was calculated; in addition, the relation between water consumption and the incoming air velocity in different temperatures was eva‎luated. The results showed that rising the velocity of the incoming air decreases the temperature difference in the two sides of the straw pad, but increases the cooling power in a fixed cross-section due to the rise in flow rate. The cooling power also grows with a rise in temperature in fixed flow rates. Regarding water consumption, a rise in velocity results in a decrease in the difference of humidity in the two sides of the straw pad; however, the flow rate increase causes growth in water consumption. Moreover, water consumption rises with a rise in the temperature of the incoming air in fixed flow rates. Eventually, a psychrometric analysis of various laboratory conditions was carried out and the share of adiabatic cooling and perceptible cooling in various velocities in evaporative coolers was studied.

محمود اشرفي زاده

محمدرضا توكلي

علي اكبر عالم رجبي، محسن دوازده امامي