Ductless mini-split air conditioners are usually designed to provide heating as well as air conditioning. In terms of cooling capacity, these units represent the middle ground between portable and whole-house AC systems. But this AC type typically has higher SEER ratings (greater efficiency) than other AC options.
The compact exterior module for a ductless AC unit delivers refrigerant to an equally compact, wall-mounted air handler that blows conditioned air throughout a room. No unsightly window installation is required. Ductless units are sized by BTU. Larger units can supply refrigerant to more than one indoor air handler.
Consider ductless air conditioning if your home has no ductwork, if you need to cool an addition or converted attic, or if you like the super-efficient heating and cooling these systems can provide.
When a house doesn't have an existing ductwork system to distribute conditioned air, it can be expensive and problematic to install a conventional central air conditioning system. In the past, homeowners would have to make do with portable room air conditioners or deal with the difficulty and expense of trying to conceal newly installed ductwork.
A ductless unit is a great option for homeowners who want the comfort and convenience of central air conditioning in a house that doesn't have a ductwork system.
Unlike a conventional forced-air system that relies on a network of ducts and a large, centrally located air handler, a ductless system includes smaller air handlers that are permanently mounted on the wall or ceiling. Each air handler is supplied with electricity, a refrigerant line connected to an outdoor compressor, and a condensate drain line.
The unit typically has remote as well as console controls, and blows conditioned air into the room. Depending on its size, a single exterior compressor unit can supply one or more room-size air handlers, and each air handler can be controlled independently.
Most mini-split systems are designed as a heating and cooling system. As with other heat pumps, the heating mode doesn't work efficiently when temperatures are below freezing.