MRCOOL O-ES-09-HP-C-230C-O1 vs Pioneer YN009GMSI24RPG
Ranking criteria: for each brand we picked its single-zone outdoor unit in the 9,000 BTU (0.75 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-09-HP-C-230C-O1 pairing has the higher HSPF2 (12.5 vs 11.8).
- Cooling efficiency: the MRCOOL O-ES-09-HP-C-230C-O1 pairing has the higher SEER2 (27.4 vs 22.1).
- Cold weather: at 5°F the MRCOOL O-ES-09-HP-C-230C-O1 pairing is rated for more heat (11,500 vs 8,000 BTU/h).
- Per 1,000 heating full-load hours, the estimated electricity difference is about $5 at the U.S. average rate.
| MRCOOL O-ES-09-HP-C-230C-O1 | Pioneer YN009GMSI24RPG | |
|---|---|---|
| Cooling BTU/h | 9,000 | 9,000 |
| SEER2 | 27.4 | 22.1 |
| EER2 | 15.4 | 14.4 |
| HSPF2 | 12.5 | 11.8 |
| Heat at 47°F | 12,000 | 11,000 |
| Heat at 17°F | 12,000 | 7,900 |
| Heat at 5°F | 11,500 | 8,000 |
| % of 47°F at 5°F | 96% | 73% |
| COP at 5°F | 1.8 | 2.18 |
| Cold climate | Yes | Yes |
| Refrigerant | R-454B (GWP:470 | Lower GWP) | R-454B (GWP:470 | Lower GWP) |
| Connected | No | No |
| Most Efficient | Yes | Yes |
| Indoor unit (pairing shown) | O-09-HP-WMAH-230C-O | CK009GMSILDFHG |
| AHRI ref. | 217447801 | 218010986 |
| Cool kWh/1,000 h (est.) | 328 | 407 |
| Heat kWh/1,000 h (est.) | 960 | 932 |
| Record | 4428961 | 4520515 |
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 Pioneer on the manufacturer's site (plain link, not an affiliate link)