Mini-Split Air Vs. Central Air Cost

Upfront Cost

• Perhaps the biggest drawback to mini-split air conditioners is the upfront cost, which is about 30 percent more than central air conditioning units per ton of cooling capacity. That is even twice as much as the upfront cost of similar-capacity window units, according to the U.S. Department of Energy.

Electrical Cost

• The electric bill is where the mini-split air conditioner has the advantage over central air. A mini-split air conditioner of 12,000 BTU (a 1-ton unit) consumes the same amount of electricity as a medium-sized, window unit air conditioner at about 1,000 watts per hour, or kilowatt hour. Standard 2.5-ton central air conditioning units, on the other hand, consume 3,500 kilowatts per hour. It would cost between one-quarter and one-third less to run a mini-split air conditioner for four hours a day, seven days a week over a standard central air conditioner.

Effectiveness

• Installation by a knowledgeable professional is key when it comes to mini-split air conditioners. It must be proper installed for size and location to get the best efficiency. The U.S. Department of Energy lists improper installation as the primary reason for short-cycling air, which is energy inefficient and causes the unit to lose cooling and humidity-control effectiveness.

Other Considerations

• While a mini-split air conditioner may be more energy efficient, the upfront cost and sometimes awkward appearance of a mini-split air conditioning unit can be a turnoff for consumers. Most split air conditioning units do not look "built-in," like central air conditioners, and must be near the window or chosen ventilation area. Another drawback is the need for draining due to condensation buildup from the outdoor portion of the unit, as the U.S. Department of Energy points out. However, the near 70-percent savings on monthly energy bills over a central unit is hard to beat without relying solely on fans.