1. Understanding SEER2 and Operating Costs

The efficiency of an air conditioner is measured by its Seasonal Energy Efficiency Ratio 2 (SEER2) rating. A higher SEER2 rating means the system requires less electrical power to produce the same amount of cooling. For heating, efficiency is measured by the Heating Seasonal Performance Factor 2 (HSPF2).

To estimate the hourly electrical cost of a mini split, use this formula:
(BTU Capacity / SEER2) / 1000 = Kilowatt-Hours (kWh) per hour of operation.

System Capacity	SEER2 Rating	Hourly kWh Usage	Estimated Monthly Cost
9,000 BTU (Bedroom)	22 SEER2	0.41 kWh	$14.76 / month
12,000 BTU (Living Room)	20 SEER2	0.60 kWh	$21.60 / month
24,000 BTU (Multi-Zone)	18 SEER2	1.33 kWh	$47.88 / month

*Monthly cost estimates are based on an average utility rate of $0.15 per kWh and 8 hours of continuous daily operation. Actual costs will vary based on climate and insulation quality. For high-efficiency system options, check out our Tax Credit Eligible Systems Guide.

2. 3 Tips to Maximize Mini Split Efficiency

While mini splits are inherently highly efficient, you can further reduce your energy consumption by following these best practices:

• Keep the Inverter Running: Do not turn the system off when you leave the house. Inverter compressors are designed to run continuously at low, energy-saving speeds. Turning them on and off forces them to run at maximum power to cool the room down.
• Clean Filters Regularly: Dirty filters restrict airflow, forcing the indoor blower motor and compressor to work harder and consume more electricity. See our Mini Split Maintenance Checklist.
• Zone Your Home: Only cool or heat the rooms you are actively using. Keep bedroom units off during the day and living room units off at night.

3. Frequently Asked Questions