Central Air Conditioners
Central air conditioners circulate cool air through a system of supply and return ducts. Supply ducts and registers carry cooled air from the air conditioner to the home. Central air conditioners have two separate components: the condenser and the evaporator. The condenser unit is usually located outside the house on a concrete slab. The evaporator coil is mounted in the plenum or main duct junction above the furnace.
If your air conditioner is installed correctly, or if major installation problems are found and fixed, it should perform efficiently for years with only minor routine maintenance. However, many air conditioners are not installed correctly. As an unfortunate result, modern energy-efficient air conditioners can perform almost as poorly as older inefficient models.
Ductless Units
A ductless heat pump or air conditioner typically consists of a wall-mounted indoor unit combined with an outside compressor. It’s most often used in a situation where a window AC unit or baseboard heating would be considered, such as a new addition to a house. But unlike window units, ductless units require only a very small hole to be drilled into the wall, making them less vulnerable to air leakage and security problems. Plus, they’re less visible and audible.
Depending on your home’s construction, ductless systems can make sense in a variety of applications, including whole-house heating and cooling. Ductless is ideal for creating independent temperature zones in different rooms.