How Your air Conditioner Works

A split-system air conditioner splits the hot side from the cold side of the system, like this: The cold side (or inside unit), consisting of the evaporator coil, is generally placed onto a furnace or air handler. The furnace pulls warm air in through the filter and then blows it through the coil and routes the cool air through the building using a series of ducts or ductwork. The hot side, known as the condenser (or outside unit), is installed outside the building. The condenser and evaporator coil are connected using 2 pieces of copper tubing .

In most home installations, the condenser unit looks something like this:

The condenser (or outside unit) consists of a coil, fan, compressor and controls. Mounted at the top of the unit is a fan, to blow air through the coil to keep it and the compressor cool. The compressor circulates refrigerant between the inside and outside units making the evaporator coil very cold. Because the hot and cold sides are split apart and the coils are larger, the efficiency is higher.

On a larger scale:

In large department stores, malls, warehouses and businesses, the condensing unit is normally installed on the roof. Although, there may be many smaller units on the roof, each one being attached to a small air handler inside that cools a specific area in the building.