For 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.
Price checked October 21, 2026. As an Amazon Associate we earn from qualifying purchases.
The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.
| Capacity (certified) | |
|---|---|
| Size (nominal) | 18,000 BTU |
| Cooling at 95 °F | 17,000 Btu/h |
| Heating at 47 °F | 18,000 Btu/h |
| Heating at 17 °F (max) | 18,700 Btu/h |
| Heating at 5 °F (max) | 9,500 Btu/h |
| Heat kept at 5 °F | 53% |
| Price per 1,000 Btu/h at 5 °F | $178 |
| Efficiency (certified) | |
| HSPF2 (Region IV) | 8.5 |
| SEER2 | 17.3 |
| EER2 | 9 |
| COP at 5 °F | 1.75 |
| ENERGY STAR | Not ENERGY STAR |
| AHRI certificate | 218004486 |
| Installation | |
| Line set connection | Quick-connect (no vacuum pump) |
| Line set | 11.5 ft included, up to 75 ft |
| Voltage | 230 V |
| Refrigerant | R-454B |
| Indoor unit | DIYS-18-HP-WMAH-230A13-O |
| Outdoor unit | DIYS-18-HP-C-230A11-O |
| Build | |
| Indoor noise | 18.5–46.5 dB(A) |
| Outdoor noise | 55 dB(A) |
| Wi-Fi | Built in |
| Room size (maker) | up to 800 sq ft |
| Weight | indoor 30.6 lb / outdoor 62.6 lb |
| Warranty | 2 yr compressor, 1 yr parts |
| Warranty with DIY install | Yes |
A low price for a self-installer who owns or will rent a vacuum pump. The Klimaire DIY is the same certified system with quick-connect lines, and Della’s Optima has near-identical ratings for less.
Pioneer Mini Split store $1,538For someone who wants a true plug-together install with no tools beyond a drill, and a warranty that survives it. Expect to pay well over the price of a flare unit with the same cold-weather output.
Amazon MRCOOL DIY Direct $2,910A middle step between MrCool’s Select and DIY 5th Gen: quick-connect and a fair warranty, but it loses much of its heat in a cold snap. Best for mild winters.
MRCOOL DIY Direct $1,806Compare the MrCool DIY Select 18,000 BTU 230V with any other DIY mini-split →
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