Ductless air conditioners have four components that are comparable to those in central air systems. Rather than circulating the air through a duct system, however, a ductless air conditioner pumps refrigerant directly from the outdoor component to the indoor component through tubing, usually made of copper, and then distributes the air drawn from the indoor unit's evaporator coil with a fan. A wireless remote or wall monitor controls the whole system, which is said to be so quiet that it is becoming more and more preferred in libraries and other public spaces.
Ductless air conditioning is widely used in commercial buildings, and for ductless households this may be an efficient and easy alternative to installing and removing a window air conditioner every year.
The indoor unit can be mounted on the wall or ceiling, making it a less intrusive feature as well, and by many accounts, the installation of a ductless air conditioner is easy, clean and does not require a lot of structural work.
Another feature that contributes to energy efficiency and comfort in ductless systems is zone control, allowing you to regulate the temperature in separate zones or rooms of the house and even set a schedule for each zone, rather than having the system working throughout the house at all times of the day. You might want to schedule the cooling of the main living area for half an hour before you return home from work, and the bedrooms for half an hour before your usual bedtime. There are zone control products available for installation with central air conditioning units as well.
Among the top air conditioning manufacturers carrying ductless air conditioning systems for the home are: Carrier, Lennox, Mitsubushi and Freidrich. Ductless air conditioning is commonly referred to as a Duct-Free Split System and the indoor and outdoor components are often sold separately, as heating and cooling or cooling-only systems.