• Match the unit to your room size: If a mini-split air conditioner is stronger than the room’s needs, it will reach the desired temperature too quickly, and then shut itself off. This short cycling actually wastes energy instead of saving it, and puts a needless strain on the unit. So, you should make sure that the air conditioner’s BTUs match the room size. These are useful specs for reference:

  • Room size from 250 square feet - 450 square feet: 9,000 BTUs

  • Room size from 550 square feet - 800 square feet: 12,000 BTUs (best for two-story home, bungalows, side-split, split entry, rec rooms)

  • Room size from 750 square feet - 1100 square feet: 15,000 BTUs

  • Room size from 850 square feet - 1250 square feet: 18,000 BTUs

Note: These figures are when the unit is used for cooling. If it can be used as a heat pump, the appliance will usually prove to be even more efficient.

• Some things to consider about the installation:

  • Tubing: Take note of the tubing that comes with the unit. Some companies provide 16 feet or 25 feet of copper tubing. This allows you to set up a line set connecting the indoor and outdoor units.

  • The hole between the indoor and outdoor units: You will also have to prepare a hole in the wall or ceiling through which to run the tubing. A 3”-diameter hole will usually suffice. A wall sleeve, usually made from polypropylene, is inserted into the hole, through which you thread the tubing.

  • Coolant: Regarding the coolant, you’ll see that some companies, such as Air-Con, will sell the outdoor unit “pre-charged”, supplied with environmentally-friendly R410A coolant, that doesn’t damage the ozone layer. However, if your unit is not pre-charged, you’ll need a HVAC professional to fill the appliance with coolant.

• Noise: Mini-split air conditioning units can have the outdoor unit separated from the indoor unit by over 16 feet. So the outdoor unit can be noisier than the indoor unit, and still not cause you much of a disturbance. The outdoor unit of the Innova 12000 BTU Mini-Split Air Conditioner operates at around 54 decibels, which is the level of normal room conversation, or a light rainfall. The indoor unit is much quieter, as only 19 decibels--that’s the equivalent of people whispering, or a ticking watch! You don’t have to worry about the air conditioner disturbing your sleep.

• Warranty: A mini-split air conditioner unit is a big investment--for example, the Senville 24,000 BTU unit is over $1400--so you want to make sure that it has an extended warranty. The Senville has a 3-year warranty on the parts, and a 7-year warranty on the compressor (which does most of the cooling work).

• Specifications on air conditioners: You’ll see a few acronyms that will help you know about the efficiency of the air conditioner that you select.

  • AHRI certified: You’ll see that air conditioners advertise to be “AHRI certified”. “AHRI” stands for “Air Conditioning, Heating, and Refrigeration Institute”. They compare the performance of air conditioning and heating products, to make sure that they comply with efficiency standards.

  • SEER: The SEER ( = Seasonal Energy Efficiency Ratio) rating tells you how well your air conditioner cools. It is a ratio of the amount of cooling that the appliance performs per unit of energy that it uses. It is measured at a standard of 82 degrees Fahrenheit, and the minimum SEER rating is 13.  The Cooper and Hunter 2-Zone air conditioner has a SEER rating of 21.3.

Della, founded in 2015, is a manufacturer of refrigerators, washers and dryers, kitchen appliances, and home comfort products such as dehumidifiers, heaters and conditioners, and air purifiers.

Innova is a company that specializes in ductless mini-split air conditioners. They are based in Alhambra, California. They pride themselves on making units that are quiet, energy-efficient, and compact. Their air conditioning units function both as heaters and coolers.

Pioneer, located in Doral, Florida, is a manufacturer of ductless mini-split heat pumps and air conditioners, in a variety of geometries: wall-mounted, ceiling cassette, floor-ceiling mounted, and floor mounted.  Their appliances also provide dehumidification and ventilation.

Senville is a maker of mini-split, multi-zone, and portable air conditioners. They also make heat pumps and water heaters. Their headquarters is located in Montreal, Quebec.

Cooper and Hunter have been makers of air conditioning and ventilation appliances since 1998. They are partners presently with the Chinese Company Zhuhai Vino Environmental Technology Equipment Company. They make single-zone mini-split air conditioners, portable air conditioners, dehumidifiers, and air conditioners for commercial use.