evaporation of water. Evaporative cooling differs from air conditioning by refrigeration and absorptive refrigeration, which use vapor-compression or absorption refrigeration cycles.

Refrigerated   

×Recirculates the same stale air

             ×Windows and doors must be shut

             ×Dries the air which can be bad for asthma and allergy sufferers

             ×Recirculated air can contain odors,germs and air borne contaminants

             ×Reduced efficiency as temperature rises

Evaporative

             √Introduces 100% fresh filtered air

             √Windows and doors left open

             √Keeps the air moist,great for allergy and asthmatic conditions

             √Full ventilation,exhausts odors,germs and airborne contaminants

             √Increased cooling capacity as outside temperature rises

climates where the air is hot and humidity is low. In dry, arid climates, the installation and operating cost of an evaporative cooler can be much lower than that of refrigerative air conditioning, often by 80% or so. However, evaporative cooling and vapor-compression air conditioning are sometimes used in combination to yield optimal cooling results. Some evaporative coolers may also serve as humidifiers in the heating season.