Pick the COSTWAY 12,000 BTU 115V Mini-Split if a professional is installing it anyway and you want the newer R-32 refrigerant. Pick the MRCOOL DIY 12,000 BTU 115V if lower running costs matter most and you plan to install it yourself.
The central trade-off
Efficiency. The MRCOOL DIY 12,000 BTU 115V is rated 22 SEER against 20 for the COSTWAY 12,000 BTU 115V Mini-Split, roughly 9% less cooling energy at the same output.
Installation. The MRCOOL DIY 12,000 BTU 115V uses pre-charged quick-connect lines for DIY installs; the other needs its lines vacuumed and opened by a technician.
Refrigerant. R-32 in the COSTWAY 12,000 BTU 115V Mini-Split, R-410A in the MRCOOL DIY 12,000 BTU 115V. New systems moved from R-410A to lower-impact A2L refrigerants in 2025; existing R-410A stock can still be installed.
Noise. The COSTWAY 12,000 BTU 115V Mini-Split lists 23 dB indoors at its quietest, against 23.5 dB.
Side by side
| Specification | COSTWAY 12,000 BTU 115V Mini-Split | MRCOOL DIY 12,000 BTU 115V |
|---|---|---|
| Cooling (maker) | 12000 BTU | 12000 BTU |
| Heating (maker) | 12300 BTU | Not stated by the maker |
| SEER2 | Not stated by the maker | 22 |
| HSPF2 | Not stated by the maker | Not stated by the maker |
| Heats down to (maker) | Not stated by the maker | Not stated by the maker |
| Voltage | 115 V AC | 115 |
| Refrigerant | R-32 | R-410A |
| Room size (maker) | 750 sq ft | 500 sq ft |
| Indoor noise (maker) | 23 db | 23.5 db |
| Line set included | Not stated by the maker | Not stated by the maker |
| Warranty | Not stated by the maker | Warranty |
Values are the makers' published specifications. "Not stated" means the maker doesn't publish it.
Which should you choose?
Choose the COSTWAY 12,000 BTU 115V Mini-Split if
- A professional is installing it anyway
- You want the newer R-32 refrigerant
- It's going in a bedroom
Choose the MRCOOL DIY 12,000 BTU 115V if
- Lower running costs matter most
- You plan to install it yourself
- You're comfortable with the long-proven R-410A design