The quality of tomatoes depends on post harvest handling, transportation and storage techniques. Tomatoes cannot be kept for a long period of time due to their perishable and seasonal nature, it is therefore necessary to preserve it in seasons when available in other to ensure constant supply throughout the year with their nutritional value still retained. However, a 0.22 cubic metre capacity storage facility that operates on the principle of evaporative cooling, which is to increase the shelf life of stored tomatoes was designed, fabricated and tested. Data were observed twice daily and Results of the transient performance tests revealed that 117W is the cooling capacity of the produce (tomatoes) at 29.50C. Also, it was observed that the dry bulb (21-300C) and wet bulb (14.5-240C) temperatures are inversely proportional to the relative humidity (39-56%) of the cooler, which in turn show inverse relationship between the saturation efficiency (0-74.42%) and by-pass factor (0.26-1.00). An evaporative cooling system should be utilized to preserve tomatoes and other forms of vegetables at their minimal storage temperature in fourteen days relative to ambient storage. Thus, it has the prospect of being used for short term preservation of tomatoes soon after harvest and it will be very useful in helping the farmers most especially in a developing economy like Nigeria. Key words: Evaporative cooling systems, tomatoes, preservation, temperature, relative humidity, cooling efficiency, cooling capacity.
