MRCOOL O-ES-12-HP-C-230C-O1 vs ACiQ ACIQ-12ZS-HP115C
Ranking criteria: for each brand we picked its single-zone outdoor unit in the 12,000 BTU (1 ton) class with the highest certified HSPF2, and show that unit's highest-HSPF2 indoor pairing. Other pairings and models from each brand may rate differently. 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).
- Heating efficiency: the MRCOOL O-ES-12-HP-C-230C-O1 pairing has the higher HSPF2 (11.6 vs 10.4).
- Cooling efficiency: the ACiQ ACIQ-12ZS-HP115C pairing has the higher SEER2 (23.2 vs 22.2).
- Cold weather: at 5°F the MRCOOL O-ES-12-HP-C-230C-O1 pairing is rated for more heat (11,500 vs 7,300 BTU/h).
- Per 1,000 heating full-load hours, the estimated electricity difference is about $22 at the U.S. average rate.
| MRCOOL O-ES-12-HP-C-230C-O1 | ACiQ ACIQ-12ZS-HP115C | |
|---|---|---|
| Cooling BTU/h | 12,000 | 12,000 |
| SEER2 | 22.2 | 23.2 |
| EER2 | 12.5 | 12.5 |
| HSPF2 | 11.6 | 10.4 |
| Heat at 47°F | 12,000 | 12,000 |
| Heat at 17°F | 10,000 | 10,000 |
| Heat at 5°F | 11,500 | 7,300 |
| % of 47°F at 5°F | 96% | 61% |
| COP at 5°F | 2 | 2.2 |
| Cold climate | Yes | No |
| Refrigerant | R-454B (GWP:470 | Lower GWP) | R-454B (GWP:470 | Lower GWP) |
| Connected | No | No |
| Most Efficient | Yes | No |
| Indoor unit (pairing shown) | CASSETTE12HP-230C-O | ACIQ-12WS-HP115C |
| AHRI ref. | 217447805 | 216980880 |
| Cool kWh/1,000 h (est.) | 541 | 517 |
| Heat kWh/1,000 h (est.) | 1,034 | 1,154 |
| Record | 4428965 | 3997794 |
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)).
See MRCOOL on the manufacturer's site (plain link, not an affiliate link)
See ACiQ on the manufacturer's site (plain link, not an affiliate link)