Fujitsu Altair 500 36,000 BTU
#1 in 36,000 BTUFull review
Fujitsu’s mainstream line for cooling and mild-winter heating, with a 10-year registered warranty. It stops heating below 5 °F.
The Fujitsu Altair 500 36,000 BTU is the better mini-split overall, rated 3.4 to 2.9. The Fujitsu Altair 500 36,000 BTU leads on efficiency and warranty. The MrCool DIY 5th Gen 36,000 BTU 230V wins on cold weather and noise.
MrCool DIY 5th Gen 36,000 BTU 230V
#2 in 36,000 BTUFull review
The pricier of the two 36,000 BTU quick-connect units, with a better heating limit and quieter indoor unit than the Klimaire. Neither keeps much of its heat in deep cold.
Amazon $3,569.99 MRCOOL DIY Direct $3,790$3,569.99
Prices 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 Fujitsu Altair 500 36,000 BTU for efficiency (10 HSPF2, 21 SEER2, COP 2.20 at 5 °F vs 8.5 HSPF2, 18 SEER2, COP 1.97 at 5 °F) and warranty (10-year compressor, 10-year parts vs 7-year compressor, 5-year parts).
- Choose the MrCool DIY 5th Gen 36,000 BTU 230V for cold weather (keeps 61% of its heat at 5 °F, heats down to -13 °F vs keeps 76% of its heat at 5 °F, heats down to 5 °F) and noise (indoor unit from 27.5 dB(A) vs indoor unit from 32 dB(A)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 36,000 BTU mini-split; a clear win is highlighted. How we rank explains each one.
| Factor weight | Fujitsu Altair 500 36,000 BTU | MrCool DIY 5th Gen 36,000 BTU 230V |
|---|---|---|
| Overall rating | 3.4/5 | 2.9/5 |
| Cold weather 40% | 31 keeps 76% of its heat at 5 °F, heats down to 5 °F | 40 keeps 61% of its heat at 5 °F, heats down to -13 °F |
| Efficiency 30% | 64 10 HSPF2, 21 SEER2, COP 2.20 at 5 °F | 21 8.5 HSPF2, 18 SEER2, COP 1.97 at 5 °F |
| Warranty 20% | 100 10-year compressor, 10-year parts | 64 7-year compressor, 5-year parts |
| Noise 10% | 38 indoor unit from 32 dB(A) | 60 indoor unit from 27.5 dB(A) |
Specifications
| Fujitsu Altair 500 36,000 BTU | MrCool DIY 5th Gen 36,000 BTU 230V | |
|---|---|---|
| Capacity (certified) | ||
| Size (nominal) | 36,000 BTU | 36,000 BTU |
| Cooling at 95 °F | 33,000 Btu/h | 36,000 Btu/h |
| Heating at 47 °F | 34,000 Btu/h | 36,000 Btu/h |
| Heating at 17 °F (max) | 30,100 Btu/h | 26,300 Btu/h |
| Heating at 5 °F (max) | 25,800 Btu/h | 22,000 Btu/h |
| Heat kept at 5 °F | 76% | 61% |
| Price per 1,000 Btu/h at 5 °F | - | $162 |
| Efficiency (certified) | ||
| HSPF2 (Region IV) | 10 | 8.5 |
| SEER2 | 21 | 18 |
| EER2 | 9.8 | 8.5 |
| COP at 5 °F | 2.20 | 1.97 |
| ENERGY STAR | ENERGY STAR Cold Climate | Not ENERGY STAR |
| AHRI certificate | 215390441 | 216032548 |
| Operating range | ||
| Heats down to | 5 °F | -13 °F |
| Cooling range | 14 to 122 °F | -13 to 122 °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 164 ft | 25 ft included, up to 75 ft |
| Voltage | 230 V | 230 V |
| Refrigerant | R-32 | R-454B |
| Indoor unit | ASUH36KPAS | DIY-36-HP-WMAH-230D25-O |
| Outdoor unit | AOUH36KPAS1 | DIY-36-HP-C-230D25-O |
| Build | ||
| Indoor noise | 32–51 dB(A) | 27.5–55.5 dB(A) |
| Outdoor noise | 54 dB(A) | 60.5 dB(A) |
| Wi-Fi | Optional module | Built in |
| Room size (maker) | - | up to 1,550 sq ft |
| Weight | indoor 36 lb / outdoor 117 lb | indoor 48.7 lb / outdoor 152.1 lb |
| Warranty | 10 yr compressor, 10 yr parts | 7 yr compressor, 5 yr parts |
| Warranty with DIY install | No, a licensed installer is required | Yes |