A central air conditioner (or heat pump) is either a split-system unit or a packaged unit. The majority of consumers have split systems in their homes.
A split-system central air conditioner has 3 components:
- an outdoor metal cabinet that contains the condenser and compressor
- an indoor cabinet that contains the evaporator coil
- an air handler, that in most cases is part of the furnace, that sends the cool air through the duct system
If your home already has a furnace but no air conditioner, a split-system is the most economical central air conditioner to install.
A packaged central air conditioner has the evaporator coil, condenser, and compressor all located in one cabinet, which usually is placed on a roof or on a concrete slab next to the house's foundation. This type of air conditioner also is used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually located outdoors. Packaged air conditioners often include electric heating coils or a natural gas furnace. This combination of air conditioner and central heater eliminates the need for a separate furnace indoors. It is generally easier to achieve high efficiency with a split system than with a packaged system.