Central air conditioning systems are far more effective and efficient than window units for residential cooling. A central air conditioning system uses a duct system to distribute cool, dehumidified air throughout the home. Supply ducts run from the air conditioner to each room in the home and deliver cooled air through the vents (or registers). A return duct system pulls air from various locations inside the home and returns it to the air conditioner. In this manner, a central air conditioning system continuously circulates air throughout the home.
There are two basic types of central air conditioning systems: split systems and packaged systems. Split systems are the most common types found in residential applications. These systems have an outdoor unit that contains the compressor and condenser. Inside the home is an air handler that contains the evaporator and a fan that blows conditioned air throughout the home.
Most split systems are combined with a furnace that is located in the indoor air handler and uses the same duct system to supply heated air when needed. Some split systems have a heat pump instead of a gas or oil fired furnace.
In a packaged system, all of the components are located in the exterior unit. Air supply and return ducts are routed to the outdoors unit and then back into the house. These types of systems are more common in small commercial buildings and can include a furnace built into the units.
If you are retrofitting a home with a central air conditioning system and the home already has an indoor furnace and duct system, a split system is usually the easiest and most economical type central air conditioning system to install. A good HVAC replacement and installation contractors like Holland Heating and Cooling recommend the best type of system for your home.