MRCOOL DIY 12K Hyper Heat Mini Split System – 5th Gen Wall Mount, -22°F Heating, 23.5 SEER2, Pre-Charged Line Set

MRCOOL® DIY 12K Hyper Heat Complete Mini-Split System – 5th Gen Wall Mount (230V)

DIY Heating & Cooling Down to -22°F with Pre-Charged QuickConnect® Line Set

The MRCOOL® DIY Hyper Heat 12K Complete Mini-Split System is a revolutionary single-zone heating and cooling solution designed for real homeowners — no vacuum pumps, no gauges, no HVAC license, and no refrigerant handling required. This bundle pairs the DIYHH-12-HP-C-230D25-O 12K Hyper Heat condenser with the DIY-12-HP-WMAH-230D25-O wall-mounted air handler to deliver efficient year-round comfort for rooms up to 550 sq. ft.

You get extreme cold weather performance down to -22°F, 23.5 SEER2 efficiency, and an installation that is almost as easy as plug-and-play thanks to the 25 ft pre-charged QuickConnect® line set. This system is ideal for 350–550 sq. ft. bedrooms, garages, finished basements, home offices, ADUs, shops, and more.

IMPORTANT: This is a 208/230V system. It does not work with 115V circuits or 115V air handlers.

Meet the First DIY Hyper Heat Mini-Split System from MRCOOL®

For the first time ever, MRCOOL® has brought Hyper Heat technology to the DIY mini-split lineup. The DIYHH-12-HP-C-230D25-O condenser delivers 12,000 BTU of heating and cooling and maintains powerful output down to -22°F, outperforming standard DIY units and portable space heaters.

There is no vacuuming, no charging, and no guesswork — simply connect the pre-charged QuickConnect® line set, tighten the fittings, and turn it on.

Paired with the DIY-12-HP-WMAH-230D25-O wall-mounted air handler, this system provides whisper-quiet indoor operation, smart WiFi controls, Amazon Alexa and Google Assistant compatibility, and a sleek, modern design that blends into any room.

True DIY Installation — Save $1,500–$3,000+ in Labor

This system uses factory-sealed, pre-charged refrigerant lines. That means:

• No vacuum pump
• No refrigerant gauges
• No nitrogen test
• No EPA certification or HVAC license

Just mount the indoor unit, set the outdoor condenser, connect the QuickConnect® line set, and plug into your 230V circuit.

The included DIYPRO® communication cable replaces traditional conduit and helps protect wiring from pets, weather, lawn equipment, and accidental damage.

Cold-Climate Performance You Can Trust

Regular mini-splits lose heating capacity quickly as outdoor temperatures drop below freezing. DIY Hyper Heat is different. Its inverter-driven compressor and R-454B refrigerant maintain stable output down to -22°F, eliminating the need for risky electric space heaters or propane.

That means:

• Better efficiency
• Lower energy bills
• Full comfort during bad winters
• Safe, all-electric operation

Smart Comfort Anywhere

Control your comfort your way:

• Included wireless remote control
• SmartHVAC™ app (iOS / Android)
• Amazon Alexa voice control
• Google Assistant voice control

Built to Last — Gold Fin® Condenser

Salt air, pollution, and humidity are no problem. The outdoor unit features Gold Fin® anti-corrosion coating that protects the coil from rust and extends the life of the condenser in both inland and coastal environments.

What's Included in This Bundle

• 1 × MRCOOL DIY Hyper Heat 12K Outdoor Condenser — DIYHH-12-HP-C-230D25-O
• 1 × MRCOOL 12K Wall-Mount Air Handler — DIY-12-HP-WMAH-230D25-O
• 25 ft Pre-Charged QuickConnect® Line Set 
• DIYPRO® communication cable
• Wireless remote control
• Installation accessories & mounting hardware
• User manual and documentation

ℹ️ Line Set Length Info

This system includes a standard 25 ft. line set. Extended line set options add an additional line set, couplers, and a longer control wire for installations requiring extra distance.

Ideal Applications

This 12K Hyper Heat system is ideal for:

• Bedrooms up to 550 sq. ft.
• Finished basements and bonus rooms
• Home offices and studios
• Airbnb / short-term rental suites
• Garage conversions and workshops
• Attic remodels and lofts
• Tiny homes and cabins
• She-sheds, man-caves, and hobby rooms
• ADUs and accessory buildings
• Detached workspaces and small shops

Hyper Heat vs. Standard DIY Mini Splits

Standard DIY mini-splits are made for moderate climates and lose heating capacity once outdoor temperatures drop below freezing. Hyper Heat technology maintains full proportional heating down to -22°F by using:

• DC inverter rotary compressor
• R-454B high-pressure refrigerant
• Variable-speed outdoor fan
• Electronic expansion valve (EEV)

The result is stable, quiet, and efficient heat even in extreme winter conditions. That makes Hyper Heat the correct choice for:

• Northern states and mountain towns
• Garage workshops and poorly insulated spaces
• Older homes without ductwork

Specifications

Outdoor Condenser — DIYHH-12-HP-C-230D25-O

Indoor Wall-Mount Air Handler — DIY-12-HP-WMAH-230D25-O

Frequently Asked Questions

Q: Do I need an HVAC technician to install this?
No. This is a true DIY system. The line set is factory-sealed and pre-charged, so no vacuum pump or gauges are required.

Q: Can I mount the air handler myself?
Yes. The wall-mount bracket and hardware are included.

Q: Does it heat well in winter?
Yes. This is a Hyper Heat system, engineered to maintain performance down to -22°F.

Q: Do I need a separate breaker for the air handler?
No. The outdoor 230V circuit powers the indoor unit. The system typically runs on a shared 15A double-pole breaker according to local code.

Q: Can I expand this system later?
No. This is a single-zone system. If you need multiple rooms, choose a MRCOOL DIY Multi-Zone system instead.