Hi friend I am used bajaj MD 2014 room air cooler it is a very good in our healt its a lose price in india.The main advantage with these two equipment is that they afford comfort. The air conditioner is used most places, but is more expensive to own and run. It cools the air and dehumidifies the air. In coastal cities this makes sense as the discomfort is both due to the high temperatures as well as the humidity. The air cooler on the other hand cools the air by the evaporation of water. The outside air is drawn through this unit onto a pad which has water running. The water evaporates and cools the air, taking the heat to evaporate from the air.The former recycles the air from the room. The latter constantly draws fresh air from outside. The advantage for the air cooler is that there is constantly outside air being drawn across into the room. The air conditioner on the other hand has a high amount of re-cycled air being cooled. The temperature reduction by an air conditioner is higher whereas for the air cooler this temperature reduction is dependent on the humidity of the place you are cooling. A humid city would have lesser cooling as compared to a dry city. The cities on the coast are normally a lot more humid compared to cities in the interior. An air cooler would be better for comfort applications as compared to an air conditioner at Delhi( interior city) as it a lot drier. Whereas at Chennai ( coastal city) an air cooler would not be as effective. From a health perspective it is always better to have more fresh air. For air conditioning in offices we require at least 5 cfm( cubic feet per minute) of fresh air per personin an office envirornment. This fresh air is required to offset the carbon-di-oxide which is being constantly produced to the occupants breathing. For an air cooler it is all fresh air being used.Besides the air conditioner guzzles a large amount of power ( 1.4 kW/ton) whereas an air cooler has basically a motor which is of a very nominal wattage. For example a 1.5-ton AC wouldconsume about 2.1 units in an hour, whereas an air cooler would consume just 0.2-0.3 units in an hour.( 1 unit is kW-hr the unit measure by our electricity board meter.)