Most efficient 18,000 BTU mini-splits (HSPF2, then SEER2)
Ranking criteria: cooling capacity in the 18,000 BTU (1.5 ton) class; ranked by HSPF2, then SEER2. Cost columns are estimates per 1,000 full-load hours at the U.S. average rate. Data: ENERGY STAR certification records retrieved 2026-10-17. Rankings are calculated from published ratings only. They are not hands-on tests or installations, and noise, price, warranty, installer availability and reliability are not considered (not in the data).
| # | Outdoor brand | Outdoor unit | Indoor unit | Cooling BTU/h | SEER2 | HSPF2 | Cold climate | Heat $/1,000 h | Cool $/1,000 h | Record |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Bryant | 37MPRAQ18AA3 | 615PHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 3624450 |
| 2 | Bryant | 37MPRAQ18AA3 | D5MPHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 4573107 |
| 3 | Carrier | 37MPRAQ18AA3 | 45MPHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 3624445 |
| 4 | Carrier | 37MPRAQ18AA3 | D5MPHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 4573111 |
| 5 | Midea | 37MPRAQ18AA3 | D5MPHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 3624465 |
| 6 | Payne | 37MPRAQ18AA3 | D5MPHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 3624455 |
| 7 | WEATHERMAKER | 37MPRAQ18AA3 | D5MPHAQ18XA3 | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 3624460 |
| 8 | MDV | MOD30-18HFN10-M1H | MSEPD-18HRFN10-M1H | 18,000 | 25.8 | 16.2 | Yes | $226 | $128 | 3553155 |
| 9 | AI AIR CONDITIONING | AO35-18N2-M1H | AW35-18N2-M1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3712452 |
| 10 | MAINLINE | ML18HP230CALH-O | ML18HP230CALH-I | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4688163 |
| 11 | KEEN Home | KEENHYMHP18AA | KEENHYMAH18AA | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4479314 |
| 12 | CanAir | 4C35SCH18H21 | 4C35SEH18H21 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4514368 |
| 13 | BLUERIDGE | BMS1826SHYC | BMS1826SHYW | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3712124 |
| 14 | BLUERIDGE | BXS6A18UC0 | BXS6A18WM0 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3997863 |
| 15 | MDV | MOD30-18HFN10-M1H | MSEPD-18HRFN10-M1H-D | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3553166 |
| 16 | Comfort Aire | A-ZHP18SA-1 | B-ZHP18SA-1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3999821 |
| 17 | Comfort-Aire | A-ZHP18SA-1 | B-ZHP18SA-1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3799257 |
| 18 | KERR | A-KZP18SA-1 | B-ZKP18SA-1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3799261 |
| 19 | KERR | A-ZKP18SA-1 | B-ZKP18SA-1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4610386 |
| 20 | Kerr Kapstone | A-KZP18SA-1 | B-KZP18SA-1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4430082 |
| 21 | MOOVAIR | MSHHA18C2AN1 | MWHHA18C2AS1 | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3723206 |
| 22 | MAINLINE | ML18HP230CALH-O | ML18HP230CALH-I* | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4479974 |
| 23 | Midea | MO1SS-H18B-2A | MSESU-H18B-2A | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3627421 |
| 24 | NOVAIR | LEA18HH-SK-O | LEA18HH-SK-I | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4708005 |
| 25 | Senville | SENE-18EL-IHH | SENE-18EL-OH | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4480155 |
| 26 | Senville | SENE-18EL-OH | SENE-18EL-IHH | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 4480260 |
| 27 | Continental | CDHAS26B-24-O | CDHAS26B-24-I | 18,000 | 25.6 | 16.2 | Yes | $226 | $129 | 3554395 |
| 28 | Airquest | D5CPRAH18AA | D5FPHAH18XAK | 18,000 | 24.5 | 15.2 | Yes | $241 | $135 | 3624557 |
| 29 | Arcoaire | D5CPRAH18AA | D5FPHAH18XAK | 18,000 | 24.5 | 15.2 | Yes | $241 | $135 | 3624487 |
| 30 | Comfortmaker | D5CPRAH18AA | D5FPHAH18XAK | 18,000 | 24.5 | 15.2 | Yes | $241 | $135 | 3624495 |
Cost estimates: cooling kWh ≈ cooling capacity × full-load hours ÷ SEER2 ÷ 1,000; heating kWh ≈ 47°F heating capacity × full-load hours ÷ HSPF2 ÷ 1,000. "Per 1,000 full-load hours" is a yardstick for comparing systems, not a prediction of your bill; your hours depend on climate, house and settings. Rate: U.S. average residential 18.31¢/kWh (EIA, July 2026 (preliminary)).