The Pros and Cons of Mini-Split Systems
Ductless, mini split-system air-conditioners (mini -splits) have numerous potential applications in residential, commercial, and institutional buildings. The most common applications are in multifamily housing or as retrofit add-ons to houses with “non-ducted” heating systems, such as hydronic (hot water heat), radiant panels, and space heaters (wood, kerosene, propane). They can also be a good choice for ADUs, room additions and small apartments, where extending or installing distribution ductwork for a central air-conditioner is not feasible or the space is small enough to work with a smaller system.
Like central systems, mini-splits have two main components: an outdoor compressor/condenser, and an indoor air-handling unit. A conduit, which houses the power cable, refrigerant tubing, suction tubing, and a condensate drain, links the outdoor and indoor units.
Pros
The main advantages of mini-splits is their small size and flexibility for zoning and cooling individual rooms. many models can have as many as four indoor air handling units connected to one outdoor unit. The number depends on how much cooling is required for each zone. This can be affexcted by how well the building is insulated and air sealed. Each of the zones will have its own thermostat, so you only need to condition that space when it is occupied, saving energy and money. Ductless mini-split systems are also often easier to install than whole house systems.
Since mini-splits have no ducts, they avoid the energy losses associated with ductwork of central forced air systems. Duct losses can account for more than 30% of energy consumption for air conditioning, especially if the ducts are in an unconditioned space such as an attic.
Compared with other add-on systems, mini-splits offer more flexibility in interior design options. The indoor air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also available. Most indoor units have profiles of about seven inches (~18 cm) deep and usually come with sleek, high-tech-looking jackets. Many also offer a remote control to make it easier to turn the system on and off when it’s positioned high on a wall or suspended from a ceiling.
Cons
The primary disadvantage of mini-splits is their cost. Such systems cost about $2,000-$2,500 per ton (12,000 BTU per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost 2x as much as window units of similar capacity.
Some people don’t like the appearance of the indoor part of the system. While less obtrusive than a window air conditioner, they seldom have the built-in look of a central system,. There must also be a place to drain condensate water near the outdoor unit.
Content provided by energy.gov
