The Senville Elite 18,000 BTU is the better mini-split overall, rated 4.8 to 2.1. The Senville Elite 18,000 BTU leads on efficiency and warranty. The MrCool DIY Select 18,000 BTU 230V wins on noise. The MrCool DIY Select 18,000 BTU 230V costs $109.99 less ($1,690 vs $1,799.99).
Senville’s top line makes more than its rated heat at 5 °F, heats to −22 °F and carries a 10-year parts and compressor warranty. Sold online, but the warranty needs a licensed installer.
Amazon $1,799.99 Senville $1,799.99For mild climates and occasional use, where a low price for a quick-connect unit matters most. The short warranty and weak cold-weather output make it a poor main heat source.
Amazon $1,690 MRCOOL DIY Direct $1,690Prices were last checked October 21, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Each factor is scored 0-100 against the same fixed reference points for every 18,000 BTU mini-split; a clear win is highlighted. How we rank explains each one.
| Factor weight | Senville Elite 18,000 BTU | MrCool DIY Select 18,000 BTU 230V |
|---|---|---|
| Overall rating | 4.8/5 | 2.1/5 |
| Cold weather 40% | 100 keeps 113% of its heat at 5 °F, heats down to -22 °F | 6 keeps 53% of its heat at 5 °F |
| Efficiency 30% | 98 16.2 HSPF2, 25.6 SEER2, COP 2.34 at 5 °F | 11 8.5 HSPF2, 17.3 SEER2, COP 1.75 at 5 °F |
| Warranty 20% | 100 10-year compressor, 10-year parts | 0 2-year compressor, 1-year parts |
| Noise 10% | 62 indoor unit from 27 dB(A) | 100 indoor unit from 18.5 dB(A) |
| Senville Elite 18,000 BTU | MrCool DIY Select 18,000 BTU 230V | |
|---|---|---|
| Capacity (certified) | ||
| Size (nominal) | 18,000 BTU | 18,000 BTU |
| Cooling at 95 °F | 18,000 Btu/h | 17,000 Btu/h |
| Heating at 47 °F | 20,000 Btu/h | 18,000 Btu/h |
| Heating at 17 °F (max) | 23,200 Btu/h | 18,700 Btu/h |
| Heating at 5 °F (max) | 22,600 Btu/h | 9,500 Btu/h |
| Heat kept at 5 °F | 113% | 53% |
| Price per 1,000 Btu/h at 5 °F | $80 | $178 |
| Efficiency (certified) | ||
| HSPF2 (Region IV) | 16.2 | 8.5 |
| SEER2 | 25.6 | 17.3 |
| EER2 | 15 | 9 |
| COP at 5 °F | 2.34 | 1.75 |
| ENERGY STAR | ENERGY STAR Cold Climate | Not ENERGY STAR |
| AHRI certificate | 217608151 | 218004486 |
| Operating range | ||
| Heats down to | -22 °F | - |
| Installation | ||
| Installed by | Professional (sold through installers) | Sold for self-install (DIY) |
| Line set connection | Flare fittings (vacuum pump needed) | Quick-connect (no vacuum pump) |
| Line set | up to 98.4 ft | 11.5 ft included, up to 75 ft |
| Voltage | 230 V | 230 V |
| Refrigerant | R-454B | R-454B |
| Indoor unit | SENE-18EL-IHH | DIYS-18-HP-WMAH-230A13-O |
| Outdoor unit | SENE-18EL-OH | DIYS-18-HP-C-230A11-O |
| Build | ||
| Indoor noise | 27–54.5 dB(A) | 18.5–46.5 dB(A) |
| Outdoor noise | 57 dB(A) | 55 dB(A) |
| Wi-Fi | Built in | Built in |
| Room size (maker) | up to 1,000 sq ft | up to 800 sq ft |
| Weight | indoor 43.6 lb / outdoor 130.3 lb | indoor 30.6 lb / outdoor 62.6 lb |
| Warranty | 10 yr compressor, 10 yr parts | 2 yr compressor, 1 yr parts |
| Warranty with DIY install | No, a licensed installer is required | Yes |
