Although swamp coolers and air conditioners were invented for the same purpose, the science behind each method is quite different.

Evaporative Coolers use water to wet absorptive pads around the sides of the cooler. A fan draws outside air through the pads and the air is cooled as the water in the pads evaporates. The major benefit of this type of cooler is that you only need to power a water pump and a fan to draw the air through the pads.

Unless the relative humidity is lower than 30% or so, swamp coolers are not very effective. At best you can achieve a 20 degree differential between outside and inside temperatures. This makes them extremely ineffective during monsoon season or days of high humidity.

As well, for an Evaporative cooler to remain effective it must exhaust as much air as it takes in. This necessitates keeping a window or door open. Since evap. coolers are constantly exchanging air, they can increase the level of pollutants and allergens within your home.

Air conditioning, on the other hand, will reliably dehumidify and cool the air, no matter what the relative humidity level is. In addition, since air conditioning does not need to exchange outside air, it is very efficient at keeping stable temperatures within your home.

Air conditioning provides reliable cooling by transferring heat from inside your home to the outside. Since the heat from your home is transferred through the use of refrigerants, your home can remain isolated from blistering outdoor temperatures.

Many individuals with allergies and other health conditions can also benefit from a central air conditioner if combined with an electronic air cleaner. Many electronic air cleaners (EAC) filter the air and remove 99.98% of all particles including allergens, mold, and dust.