What is a Mini-Split?
Ductless mini splits are designed to provide quiet, efficient cooling and heating. A mini split has an outside condenser unit and at least one indoor blower unit mounted on the wall or ceiling which provides point-of-use air conditioning in the room where it is installed.
Split systems can be used in single zone or multi-zone applications. A single zone has one indoor and outdoor unit and is designed for use in a single room or area. A multi-zone split system combines a single outdoor condensing unit with up to four indoor units, each of which works independently and can be set to different temperatures. Multi-zone systems are most often used to cool multiple areas in a home or business.
Mini splits are comprised of 4 components: a condensing unit, located outside the building; an indoor unit, mounted on the wall or ceiling; refrigerant lines, which connect the outdoor and indoor units; and a remote control, which controls the temperature and other settings.
When to Use a Mini-Split
Ductless systems are used in a variety of different applications. They are a good choice for homes without ductwork available for central air conditioning. They are also used in rooms or areas where installing ductwork might be impractical, such as attics, basements, garages and additions. Mini splits are increasingly used in new construction because of their low-profile design, energy savings and potentially lower installation costs.
Mini-splits are also quieter and more efficient than window-mounted air conditioners and are a good alternative in situations where window-mount units are impractical, such as rooms with limited window space.
Advantages and Disadvantages
Ductless systems have many advantages (and a few disadvantages) when compared to central air conditioning systems and window units:
- Noise reduction. With the compressor located outside, ductless units are quieter than window units and central air.
- Higher efficiency. While central air systems lose up to 30% of energy through ductwork, ductless systems eliminate this loss. Also, ductless indoor units allow for independent zones, with each unit adjusted with an individual thermostat. This allows unoccupied rooms to be set lower, resulting in energy savings.
- No Ductwork. Unless installed during new construction, installing ductwork requires cutting open walls and ceilings. And if ductwork is already in place, installing a new central air unit often requires retrofitting the ductwork. A mini-split requires no ductwork, eliminating this problem.
- Healthy air. Dirt, debris, and even mold can accumulate in the ductwork of a central air system over time. And window units are very difficult to seal, allowing outdoor contaminants inside the house. Ductless systems are very easy to clean and keep the air in your home cleaner.
- Easier to install than central air and often less costly.
- Can provide both heating and cooling.
- More difficult to install than window units.
- More expensive to install than window units and can be more expensive to install than central air, depending on the number of zones.
- May be difficult to find an experienced installer and service person due to the relative newness of ductless systems.
According to a 2012 report by the U.S. Department of Energy, mini splits cost about $1,500 to $2,000 per ton (12,000 Btu per hour) of cooling capacity – roughly 30% more than central air systems and approximately five times more expensive than window units.
It is important to know the amount of BTUs needed to heat or cool the square footage of your room. Here is a good general guideline:
- 350 – 400 square feet: 9,000 BTU
- 450 – 600 square feet: 12,000 BTU
- 650 – 900 square feet: 18,000 BTU
- 900 – 1150 square feet: 24,000 BTU