One of the optimal goals in building or remodeling a home is to have it be as energy efficient as possible—who doesn’t want to save money on heating and cooling? Mini-split heat pumps have been used around the world for many years. But they have been gaining in popularity in the United States in recent years because of their energy efficiency, size, ease of installation and the ability to zone the different areas of the house. Ductless heating and cooling systems, also known as mini-splits and ductless heat pumps, were first introduced to the U.S. just about 35 years ago from Japan.
These systems are un-ducted so there is no leaking air from ducts. According to the United States Department of Energy, “Duct losses can account for more than 30% of energy consumption for space conditioning, especially if the ducts are in an unconditioned space such as an attic.” Ductless systems require just a small three-inch hole in the wall connecting the interior and exterior units. Particularly in renovations, it is much simpler and less expensive to install a ductless system than one that requires ripping out walls and ceilings to install ducts.
In the past, many homeowners were reluctant to use these systems because they didn’t like the look of the interior units. However, the indoor units can now be recessed in the ceiling or mounted near the floor so they are less apparent than the units installed on the upper wall.
Mini-split ductless systems are composed of three main parts—an indoor air-handling unit, an outdoor compressor/ condenser unit, and a remote control that operates the system. A smartphone or computer can also control some units. Heat is transferred using refrigerant expansion and compression, in much the same way as a refrigerator works.
