Katherine Allen
Contributor
One of my friends recently installed a ductless air conditioner (AC) in a room they had built onto their home. I first saw them 20 years ago on a visit to Italy, but only now are we seeing adoption in the USA. Just as the ductless system name implies, there are no ducts or ductwork required. These units are also known as mini-splits, as they are smaller than the split AC units (what you have if it isn’t a window AC unit). This is a great option if you add on to a home or enclose a porch and want heating and cooling without the utility cost from a window unit. Mini-splits use approximately 30 percent less power than window air conditioners and take up less space.
Just like a traditional split system, the ductless unit has two parts: an outdoor unit that houses the condenser (the loudest component) and an air handling unit. In a traditional split system, the air handler would typically be found in the garage, in the attic or inside a closet inside the home. In the mini, the air handler is inside either on the wall, in the ceiling (best for large room) or floor mounted. The power, condensation and refrigerant lines are connected to both units through a hole in the wall. My friend’s unit included a convenient remote, as theirs is located high on the wall.
If you are considering purchasing one of these, make sure you have the appropriate sizing for the space.
• 9,000 BTU (British Thermal Unit) for areas up to 450 square feet.
• 12,000 BTU for areas 400 to 650 square feet.
• 18,000 BTU for areas 600 to 1,000 square feet.
• 24,000 BTU for areas 800 to 1,300 square feet.
• 30,000 BTU for areas 1,500 to 2,000 square feet.
• 36,000 BTU for areas over 2,000 square feet.
In addition to the correct size, you will want to make sure the unit is energy efficient. The US Department of Energy requires a SEER (Seasonal Energy Efficiency Ratio) of 15 or more (which is code in Florida as of Jan. 1, 2023). The higher the number, the higher the energy efficiency (and typically cost). Look for Energy Star rated products. If you are purchasing a unit that has a heat pump, look for an HSPF (Heating Seasonal Performance Factor) of eight to 10.
The biggest drawback is the cost. Check with your local installer for prices near you.
If you have added onto your house or enclosed a porch or work in a hot garage, this may be a solution to consider. For more information about energy efficiency or to register for a homebuyer course, contact Katherine Allen at (386) 362-2771 at the UF/IFAS Extension in Suwannee County, an equal opportunity institution.