For cold-climate homes where a quick-connect install matters more than price: it holds its full heat far colder than other quick-connect units. Flare-connect units match its cold-weather output for much less.
Amazon $2,532 MRCOOL DIY Direct $2,557The MrCool DIY Hyper Heat 5th Gen 12,000 BTU 230V is the better DIY mini-split overall, rated 3.8 to 2.5. The MrCool DIY Hyper Heat 5th Gen 12,000 BTU 230V leads on warranty and efficiency. The MrCool DIY Select 12,000 BTU 115V costs $1,133 less ($1,399 vs $2,532).
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.
Amazon $1,549 MRCOOL DIY Direct $1,399Prices 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.
Which should you buy?
- Choose the MrCool DIY Hyper Heat 5th Gen 12,000 BTU 230V for warranty (7-year compressor, 5-year parts vs 2-year compressor, 1-year parts) and efficiency (10 HSPF2, 23.5 SEER2, COP 1.80 at 5 °F vs 9 HSPF2, 17.5 SEER2, COP 1.75 at 5 °F).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 12,000 BTU DIY mini-split; a clear win is highlighted. How we rank explains each one.
| Factor weight | MrCool DIY Hyper Heat 5th Gen 12,000 BTU 230V | MrCool DIY Select 12,000 BTU 115V |
|---|---|---|
| Overall rating | 3.8/5 | 2.5/5 |
| Value 35% | 48 $230 per 1,000 Btu/h of heat at 5 °F | 50 $226 per 1,000 Btu/h of heat at 5 °F |
| Cold weather 25% | 90 keeps 92% of its heat at 5 °F, heats down to -22 °F | 4 keeps 52% of its heat at 5 °F |
| Efficiency 20% | 57 10 HSPF2, 23.5 SEER2, COP 1.80 at 5 °F | 20 9 HSPF2, 17.5 SEER2, COP 1.75 at 5 °F |
| Warranty 15% | 64 7-year compressor, 5-year parts | 0 2-year compressor, 1-year parts |
| Noise 5% | 100 indoor unit from 18 dB(A) | 100 indoor unit from 17.5 dB(A) |
Specifications
| MrCool DIY Hyper Heat 5th Gen 12,000 BTU 230V | MrCool DIY Select 12,000 BTU 115V | |
|---|---|---|
| Capacity (certified) | ||
| Size (nominal) | 12,000 BTU | 12,000 BTU |
| Cooling at 95 °F | 12,000 Btu/h | 12,000 Btu/h |
| Heating at 47 °F | 12,000 Btu/h | 12,000 Btu/h |
| Heating at 17 °F (max) | 12,500 Btu/h | 7,400 Btu/h |
| Heating at 5 °F (max) | 11,000 Btu/h | 6,200 Btu/h |
| Heat kept at 5 °F | 92% | 52% |
| Price per 1,000 Btu/h at 5 °F | $230 | $226 |
| Efficiency (certified) | ||
| HSPF2 (Region IV) | 10 | 9 |
| SEER2 | 23.5 | 17.5 |
| EER2 | 12.8 | 8.5 |
| COP at 5 °F | 1.80 | 1.75 |
| ENERGY STAR | ENERGY STAR Cold Climate | Not ENERGY STAR |
| AHRI certificate | 216032549 | 218004485 |
| Operating range | ||
| Heats down to | -22 °F | - |
| Cooling range | -22 to 122 °F | - |
| Installation | ||
| Line set connection | Quick-connect (no vacuum pump) | Quick-connect (no vacuum pump) |
| Line set | 25 ft included, up to 75 ft | 11.5 ft included, up to 75 ft |
| Voltage | 230 V | 115 V |
| Refrigerant | R-454B | R-454B |
| Indoor unit | DIY-12-HP-WMAH-230D25-O | DIYS-12-HP-WMAH-115A13-O |
| Outdoor unit | DIYHH-12-HP-C-230D25-O | DIYS-12-HP-C-115A11-O |
| Build | ||
| Indoor noise | 18–45.5 dB(A) | 17.5–44.5 dB(A) |
| Outdoor noise | 56.5 dB(A) | 54 dB(A) |
| Wi-Fi | Built in | Built in |
| Room size (maker) | up to 550 sq ft | up to 550 sq ft |
| Weight | indoor 24.5 lb / outdoor 72.3 lb | indoor 24.9 lb / outdoor 54.9 lb |
| Warranty | 7 yr compressor, 5 yr parts | 2 yr compressor, 1 yr parts |
| Warranty with DIY install | Yes | Yes |
