For comfort conditions we generally use an air conditioner (AC). The main drawback of an AC is that it consumes large amount of power about 1KW. Also the air conditioner is not cost effective. The alternative for the air conditioner is Evaporative cooler. But the drawback of an evaporative cooler is that it increases the humidity of the supply air.

The present design combines the advantages of both the air conditioner and the evaporative cooler, viz. good cooling effect and comfort conditions of AC and low cost of evaporative cooler. The project involves attachment of ‘Split unit’ to the conventional evaporative cooler.

The new design consist of following factors-
• The conventional evaporative cooler.
• A duct or split unit consisting of three heat exchangers and a fan to supply air.
• Pump to supply cool water to the heat exchangers

There will be two pumps. First pump is used to circulate water in the evaporative cooler itself, the second pump will supply water from tank of evaporative cooler to the split unit. The split unit will be placed in a room to be cooled and it will take the air from the room and will circulate to the room itself. And the evaporative cooler will be placed outside the room.

The working of the unit is as follows-
I. The water in the tank of evaporative cooler is cooled due to evaporative action of the cooler. The temperature of water in the tank is about 21°C. So this cool water is supplied to the three heat exchangers in the split unit which is placed inside the room to be cooled.
II. The material for heat exchangers is copper and the fins are made of aluminium. Due to supply of cool water the heat exchangers will become cool. The fan placed in the split unit will circulate the air from the room over the heat exchangers.
III. So the air will become cool and its humidity will remain constant as it will not come in direct contact with water. As per our results we are able to get cool air of temperature 22°C.
IV. The water from heat exchangers will return to the tank of evaporative cooler. The water will get cool again due to evaporative action of the cooler and it will resupplied to the heat exchangers.
V. This cooler is very useful in the regions of high humidity.

Advantages of the design
• This design supplies cool and nonhumidfied air which is comfortable than that supplied by conventional cooler.
• The cooler can maintain temperature at 22°c which almost equal to an AC and its power consumption is also very low (200 W) than that of AC (1 KW) so the cooler will be a good option for common man.
• It is very cheaper as compared to an AC unit.
• It can cool two rooms at a time as the air from evaporative cooler can also be utilized to cool a space.