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Mini Split Energy Savings Calculator
See what an inverter mini split costs to run compared with an old window unit, a portable AC or electric space heat. Uses each model's published SEER2 and HSPF2 ratings, your electricity rate and your climate.
- Published SEER2 and HSPF2 per model
- Climate-based run hours
- Payback and 10-year savings
The system you are considering
19 SEER2, HSPF2 8.5 (Region IV) and 7.2 (Region V).
What you use today
For cooling
For heating
Your home and rate
Printed on your power bill. Pre-filled with a typical US residential rate.
Adjust the assumptions +
Hours are full-load equivalents: how long the system would run at full output to do a year of work. Central AC efficiency is reduced 20% for typical duct losses.
The method
How the estimate is calculated
SEER2 and HSPF2 are ratios of heat moved to electricity used over a season. Divide the work a room needs by the rating and you get the energy it takes.
BTU per hour × hours a year ÷ (SEER2 × 1,000) = kWh a year
Heating uses HSPF2 in the same place. Electric resistance heat, like a space heater or baseboard, turns one watt-hour into 3.412 BTU, so it is equivalent to an HSPF2 of about 3.4.
SEER2 is the cooling season rating
The 2023 federal test replaced SEER with SEER2, using higher airflow resistance to reflect real installs. Higher is better. See every model on the compare page.
HSPF2 is the heating season rating
Published for two climate regions. Region IV covers most of the country; Region V is the cold-climate rating and is always lower. The calculator uses the Region V figure when you choose a cold climate.
Why old units cost so much more
Older window and portable units cycle their compressor fully on and off. Inverter mini splits vary compressor speed to match the load, which is where most of the saving comes from. Our buying guide explains inverters in plain terms.
Reference
Efficiency ratings by model
As published on each product's spec sheet. Where a rating has not been confirmed on a current spec sheet we say so rather than estimate it.
| Model | Cooling BTU | SEER2 / CEER | EER2 | HSPF2 Region IV | HSPF2 Region V | Price |
|---|---|---|---|---|---|---|
| 9,000 BTU mini split MSCT-09HAC1 | 9,000 | 23 | 12.5 | 9 | 7.76 | $640 |
| 12,000 BTU mini split MSC-12HAC1 | 12,000 | 19 | 10 | 8.5 | 7.2 | $720 |
| 12,000 BTU mini split, 17 SEER2 MSCR32-12CHSA1 | 11,500 | 17 | 9.5 | 9.5 | 8.1 | $735.50 |
| 23,000 BTU mini split MSCR32-23CHSA2 | 23,000 | 17 | 9.5 | 9.5 | 8.5 | $1,250 |
| DUET 2-zone MZR454B-DUETSERIES | 18,000 | 24 | 13 | 10.5 | 9.5 | $2,059 |
| 8,000 BTU window AC TWC-08CRD1/L0U | 8,000 | 12 CEER | 12.1 | n/a | n/a | $280 |
| 12,000 BTU window AC TWC-12CRD1/L0U | 12,000 | 12 CEER | 12.1 | n/a | n/a | $380 |
DUET ratings are the ENERGY STAR non-ducted figures for the wall-mounted indoor units it ships with.
Selling or installing? Show customers the numbers.
Run the calculator with your customer's rate and climate, and the running cost comparison makes the case for an inverter system on its own. Trade pricing is available through the pro program.
Questions
Energy savings FAQ
How much does a mini split cost to run per month?
It depends on size, climate and your electricity rate. Pick a model and your climate in the calculator and divide the yearly figure by twelve for a monthly average. Summer and winter months run higher than spring and fall. Not sure which model? Start with the Size Finder.
Is a mini split cheaper to run than a space heater?
For the same heat, usually by a wide margin. A space heater delivers 3.412 BTU per watt-hour. A heat pump rated 9 HSPF2 delivers about 9 BTU per watt-hour across the season, so it uses roughly a third of the electricity for the same warmth. The 9,000 BTU mini split is rated 9 HSPF2 in Region IV.
What is the difference between SEER and SEER2?
SEER2 is the rating used since January 2023. The test conditions are tougher, so a given system scores lower on SEER2 than it did on SEER. Compare SEER2 with SEER2 and SEER with SEER; the numbers are not interchangeable.
Are there rebates or tax credits for mini splits?
Utility rebates vary by provider and by model certification. Check with your electric utility before buying, and see our rebates and incentives guide.
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Plan the rest of the project
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