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How we rank products

The formula is the same on every comparison: official ENERGY STAR figures, published weights, and no paid placement.

1. Specs come from official ENERGY STAR records

We enter only figures published on the ENERGY STAR certified mini-split heat pump dataset, and we link the product-finder search and the public dataset under every product. If a figure isn't published we show "Not listed" instead of guessing. Official ratings are for the certified outdoor and indoor combination shown; a different official indoor head can change those figures, and we note that when the record lists other matchups. Official cooling and heating capacities, official refrigerant type, official cold-climate designation and official AHRI reference numbers are shown as extra details when the record lists them. Indoor-head style, line-set length and sound level are almost never on this dataset, so those facts stay Not listed.

2. Scores use a fixed reference range

Each criterion has a fixed reference range, from a "weakest reasonable" value to a "best in class" value (for example 16 to 28 official SEER2, or 1.5 to 2.6 official COP at 5°F). A product's figure is placed on that range and clamped between 0 and 1, so scores stay meaningful as products are added. Official SEER2 above 28, official HSPF2 above 13, official EER2 above 16, and official COP at 5°F above 2.6 are clamped at those reference bests. The official figures still appear on the product page. The ranges are listed below.

Compact mini-split heat pumps

  • Official SEER2 · weight 30 · range 16–28 — The official SEER2 cooling-efficiency rating published on the ENERGY STAR certified mini-split heat pump record, in Btu/Wh. It is the certified combination rating for the outdoor and indoor units shown, not a seasonal bill we measured. Official figures above 28 are clamped at the 28 reference best.
  • Official HSPF2 · weight 25 · range 8–13 — The official HSPF2 heating-efficiency rating published on the ENERGY STAR record, in Btu/Wh. It is the certified combination rating, not a winter heating test we ran. Official figures above 13 are clamped at the 13 reference best.
  • Official EER2 · weight 20 · range 9–16 — The official EER2 cooling-efficiency rating published on the ENERGY STAR record, in Btu/Wh. EER2 is a certified steady-state figure at a stated test condition, not a seasonal measurement we made. Official figures above 16 are clamped at the 16 reference best.
  • Official COP at 5°F · weight 25 · range 1.5–2.6 — The official coefficient of performance at 5°F published on the ENERGY STAR record. Higher official COP at 5°F means more certified heating output per unit of input at that cold-climate test point. It is a certified laboratory figure, not a test at a house we ran. If the field is blank it is shown as Not listed. Official figures above 2.6 are clamped at the 2.6 reference best.

Mid-capacity mini-split heat pumps

  • Official SEER2 · weight 30 · range 16–28 — The official SEER2 cooling-efficiency rating published on the ENERGY STAR certified mini-split heat pump record, in Btu/Wh. It is the certified combination rating for the outdoor and indoor units shown, not a seasonal bill we measured. Official figures above 28 are clamped at the 28 reference best.
  • Official HSPF2 · weight 25 · range 8–13 — The official HSPF2 heating-efficiency rating published on the ENERGY STAR record, in Btu/Wh. It is the certified combination rating, not a winter heating test we ran. Official figures above 13 are clamped at the 13 reference best.
  • Official EER2 · weight 20 · range 9–16 — The official EER2 cooling-efficiency rating published on the ENERGY STAR record, in Btu/Wh. EER2 is a certified steady-state figure at a stated test condition, not a seasonal measurement we made. Official figures above 16 are clamped at the 16 reference best.
  • Official COP at 5°F · weight 25 · range 1.5–2.6 — The official coefficient of performance at 5°F published on the ENERGY STAR record. Higher official COP at 5°F means more certified heating output per unit of input at that cold-climate test point. It is a certified laboratory figure, not a test at a house we ran. If the field is blank it is shown as Not listed. Official figures above 2.6 are clamped at the 2.6 reference best.

Large mini-split heat pumps

  • Official SEER2 · weight 30 · range 16–28 — The official SEER2 cooling-efficiency rating published on the ENERGY STAR certified mini-split heat pump record, in Btu/Wh. It is the certified combination rating for the outdoor and indoor units shown, not a seasonal bill we measured. Official figures above 28 are clamped at the 28 reference best.
  • Official HSPF2 · weight 25 · range 8–13 — The official HSPF2 heating-efficiency rating published on the ENERGY STAR record, in Btu/Wh. It is the certified combination rating, not a winter heating test we ran. Official figures above 13 are clamped at the 13 reference best.
  • Official EER2 · weight 20 · range 9–16 — The official EER2 cooling-efficiency rating published on the ENERGY STAR record, in Btu/Wh. EER2 is a certified steady-state figure at a stated test condition, not a seasonal measurement we made. Official figures above 16 are clamped at the 16 reference best.
  • Official COP at 5°F · weight 25 · range 1.5–2.6 — The official coefficient of performance at 5°F published on the ENERGY STAR record. Higher official COP at 5°F means more certified heating output per unit of input at that cold-climate test point. It is a certified laboratory figure, not a test at a house we ran. If the field is blank it is shown as Not listed. Official figures above 2.6 are clamped at the 2.6 reference best.

3. Missing official figures never beat published ones

When a scored field is Not listed, it receives the category minimum for that criterion. An unpublished number cannot outrank a published one. We do not use prices or customer ratings, even if a retailer later lists them.

4. What the score cannot tell you

Specs don't capture whether the official cooling capacity matches your room, how many indoor heads an outdoor unit can support, or how quiet an indoor unit is. Official SEER2 and HSPF2 are certified combination ratings, not bills we measured. Official COP at 5°F is a laboratory figure at that test point, not a winter we observed. Use the score to shortlist, then read the pros, cons, safety notes and sources, and confirm the current official specification with the maker, the installer and the retailer. When we add hands-on testing notes, we label them clearly.