MRCOOL DIY 5th Gen 12,000 BTU Mini-Split | Up to 550 Sq Ft, 115V, No Technician Required
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🛡 Warranty: Manufacturer warranty included. Coverage varies by product — see product description below for full warranty details.
Best for: Bedrooms, offices, cabins, additions, and smaller shop spaces that need a practical DIY heat-pump setup.
Why people buy it: MRCOOL DIY gives capable buyers a way to install a ductless system without opening refrigerant lines.
Watch out for: Most regrets come from poor sizing, bad placement, electrical assumptions, or sloppy condensate routing. Plan those before you buy.
The 12,000 BTU is the most popular size in the MRCOOL DIY line for a reason. It handles a single large room, a cabin great room, a converted garage, or a 550-square-foot off-grid living space on a standard 115V circuit. The 5th Generation adds R-454B refrigerant with a built-in leak sensor, improved efficiency ratings, and the same pre-charged quick-connect line set that made the original DIY a category favorite. No HVAC contractor needed at any point in the process.
MRCOOL DIY 12,000 BTU Key Features
- True DIY installation — pre-charged R-454B line set; quick-connect fittings that don't require a vacuum pump or refrigerant handling certification
- Heats down to -13°F — heat pump operation in sub-zero conditions; viable for year-round off-grid heating in cold climates
- 20+ SEER2 efficiency — pairs well with solar setups from Renogy or BLUETTI; significantly lower operating cost than resistance heating
- 115V operation — runs on a standard 20-amp household circuit; no panel upgrade needed in most installations
- WiFi and voice control — MRCOOL Smart HVAC app (iOS/Android), Google Assistant and Alexa compatible
- Gold Fin condenser coil — corrosion-resistant coating; rated for coastal and high-humidity environments
- A2L refrigerant leak sensor — built-in alarm monitors for R-454B leaks
- Quiet operation — indoor air handler designed for low noise; suitable for bedrooms and living areas
Specifications
| Cooling Capacity | 12,000 BTU |
| Heating Capacity | 12,000 BTU |
| Coverage Area | Up to 550 sq ft |
| Voltage | 115V, 60Hz, 1PH |
| Refrigerant | R-454B (pre-charged) |
| Included Line Set Length | 25 ft |
| Max Line Set Length | 82 ft |
| Min Operating Temp (Heating) | -13°F |
| Model Number | DIY-12-HP-WM-115D25-O |
| Certifications | UL, ETL, AHRI, Energy Star |
| Warranty | 5 years parts / 7 years compressor |
What's Included
- Indoor wall-mount air handler
- Outdoor condenser unit (pre-charged with R-454B)
- 25 ft pre-charged quick-connect line set
- Smart HVAC Controller Module (WiFi)
- DIYPro cable
- Remote control
- Installation hardware and mounting plate