Single units, sometimes referred to as monoblocs, are instantly recognisable by their exhaust hose which is used to expel the hot and damp air to the outside.

Single units are usually air cooled although some products are also water cooled, sometimes referred to as evaporative coolers. With water cooled units warm air passes over a wet filter inside the cooler which causes the water to evaporate, absorbing the heat and providing fresh cool air.

Split units have separate evaporator and condenser units and are therefore more powerful than monobloc air condioners. The main unit is positioned inside the room where the cooling is required and is connected to the condenser which is positioned outside to expel the warm air.

Evaporative coolers work by a natural process of evaporation - hot air passing over the water in the cooler causes water to evaporate thus absorbing heat and producing a cool breeze.

Evaporative coolers draw air through water saturated cellulose fibre filters which are treated to give them high absorbency.

Air movers can be generally classified as fans or blowers. Fans are usually axial fans or propellers that produce low-pressure air movement. Blowers are usually centrifugal devices that deliver air at a higher pressure, usually for a process such as a reaction, as well as cooling.