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

The MRCOOL® DIY 12K Hyper Heat Complete Mini Split System is a 5th Generation single-zone ductless heat pump designed for true cold-climate heating and efficient cooling. This complete 208/230V bundle pairs the DIYHH-12-HP-C-230D25-O 12,000 BTU Hyper Heat outdoor condenser with the DIY-12-HP-WMAH-230D25-O wall-mounted air handler, making it an excellent choice for bedrooms, home offices, finished basements, garages, workshops, ADUs, cabins, and other spaces up to 550 sq. ft.

Built for real winter performance, this MRCOOL Hyper Heat system provides heating operation down to -22°F while delivering up to 23.5 SEER2 cooling efficiency. The included 25 ft pre-charged QuickConnect® line set allows for homeowner-friendly installation without a vacuum pump, refrigerant gauges, nitrogen, or field refrigerant handling.

Important: This is a 208/230V system. It does not work with 115V circuits or 115V air handlers. Because apparently electricity still insists on having rules.

What's Included in This Bundle?

• DIYHH-12-HP-C-230D25-O – MRCOOL DIY Hyper Heat 12K Outdoor Condenser
• DIY-12-HP-WMAH-230D25-O – MRCOOL 12K Wall-Mount Air Handler
• 25 ft Pre-Charged QuickConnect® Line Set
• DIYPRO® Communication Cable
• Wireless Remote Control
• Installation Accessories
• Mounting Hardware
• User Manual and Documentation

Key Features

• 12,000 BTU heating and cooling capacity
• Designed for rooms up to 550 sq. ft.
• Hyper Heat performance down to -22°F
• High-efficiency operation with up to 23.5 SEER2
• DIY-friendly QuickConnect® pre-charged line set
• No vacuum pump, gauges, nitrogen, or field refrigerant handling required
• 208/230V single-zone system
• DC inverter rotary compressor for efficient comfort control
• Quiet wall-mounted indoor air handler
• Built-in WiFi control with MRCOOL SmartHVAC™ App
• Amazon Alexa® and Google Assistant® compatible
• Gold Fin® anti-corrosion outdoor condenser coating
• Reusable washable filter

Ideal Applications

• Bedrooms up to 550 sq. ft.
• Finished basements and bonus rooms
• Home offices and studios
• Garage conversions and workshops
• Airbnb and short-term rental suites
• Attic remodels and lofts
• Tiny homes and cabins
• She-sheds, hobby rooms, and detached workspaces
• ADUs and accessory buildings
• Small shops and single-room commercial spaces

True DIY Installation

The MRCOOL DIY Hyper Heat system uses factory-sealed, pre-charged QuickConnect® refrigerant lines. The line set is designed to connect without vacuuming, refrigerant charging, or specialized HVAC tools. Mount the indoor unit, place the outdoor condenser, connect the QuickConnect® line set, connect the DIYPRO® cable, and complete the required 208/230V electrical connection according to local code.

A licensed electrician is recommended for the electrical hookup. The refrigerant connection is DIY-friendly, but electricity remains annoyingly committed to hurting people who disrespect it.

Line Set Length Information

This system includes a standard 25 ft QuickConnect® pre-charged line set. Extended line set options may include an additional line set, couplers, and a longer control wire for installations that require more distance between the indoor air handler and outdoor condenser.

QuickConnect® line sets should not be cut. Any extra line set length should be properly coiled and installed according to MRCOOL installation guidelines.

Hyper Heat vs Standard DIY Mini Splits

Standard DIY mini split systems are excellent in mild and moderate climates, but many begin losing heating capacity when outdoor temperatures drop below freezing. The MRCOOL DIY Hyper Heat system is designed for colder regions and more demanding spaces where dependable winter heating matters.

The inverter-driven compressor, R-454B refrigerant, variable-speed outdoor fan, and electronic expansion valve help this system maintain stable heating operation down to -22°F. That makes it a smart choice for northern states, mountain towns, garage workshops, older homes without ductwork, and rooms that need year-round comfort.

Outdoor Condenser Performance Specifications

Specification	Value
Outdoor Model	DIYHH-12-HP-C-230D25-O
System Type	Single-Zone Hyper Heat Mini Split
Cooling Capacity	12,000 BTU
Heating Capacity	12,000 BTU
Recommended Coverage Area	Up to 550 sq. ft.
SEER2	23.5
EER2	12.8
HSPF2-4	10
HSPF2-5	8
Inverter	Yes – DC Rotary Compressor
Minimum Heating Ambient Temperature	-22°F
Minimum Cooling Ambient Temperature	-22°F
Outdoor Noise Level	56.5 dB

Outdoor Condenser Electrical Specifications

Electrical Specification	Value
Voltage	208/230V
Phase	1 Phase
Frequency	60 Hz
Minimum Circuit Ampacity	15 A
Maximum Fuse / Breaker	15 A
Dedicated Circuit Required	Yes

Refrigeration & Piping Specifications

Refrigeration Specification	Value
Refrigerant Type	R-454B, Factory Pre-Charged
Included Line Set Length	25 ft QuickConnect®
Maximum Line Set Length	75 ft
Liquid Line Size	1/4 in.
Suction Line Size	3/8 in.
Field Vacuum Required	No
Field Refrigerant Charging Required	No

Indoor Wall-Mount Air Handler Specifications

Indoor Unit Specification	Value
Indoor Model	DIY-12-HP-WMAH-230D25-O
Indoor Unit Type	Wall-Mounted Air Handler
Cooling / Heating Capacity	12,000 BTU
Recommended Room Size	Up to 550 sq. ft.
Mounting Type	Wall-Mounted
Voltage	208/230V, Powered from Outdoor Unit
Fan Speeds	5-Speed Fan
Sound Rating	Approx. 19–54.5 dB
Operating Modes	Cool, Heat, Auto, Dry, Fan, Sleep
Filter	Reusable Washable Filter

Smart Control Features

Smart Feature	Included
WiFi Enabled	Yes
App Control	MRCOOL SmartHVAC™ App for iOS and Android
Amazon Alexa® Voice Control	Yes
Google Assistant® Voice Control	Yes
Wireless Remote Control	Included
Programmable Timer	Yes
Auto Mode	Yes
Sleep Mode	Yes
Dry / Dehumidification Mode	Yes

Warranty Coverage

Warranty Item	Coverage
Compressor Warranty	7-Year Compressor Warranty with Registration
Parts Warranty	5-Year Parts Warranty with Registration
Extended Coverage	Limited Lifetime Compressor Replacement Available with MRCOOL® Care Enrollment

Frequently Asked Questions

Do I need an HVAC technician to install this MRCOOL DIY Hyper Heat system?

The refrigerant line set connection is designed for DIY installation using MRCOOL QuickConnect® pre-charged line set technology. No vacuum pump, gauges, nitrogen, or field refrigerant handling are required. A qualified electrician is recommended for the required 208/230V electrical connection.

Can I mount the wall air handler myself?

Yes. The wall-mount bracket and mounting hardware are included. Always follow the installation manual for clearances, mounting height, drain routing, and line set routing.

Does this system heat well in winter?

Yes. This is a MRCOOL Hyper Heat system engineered for cold-climate heating operation down to -22°F.

Do I need a separate breaker for the indoor air handler?

No. The indoor wall-mounted air handler is powered from the outdoor unit. The outdoor condenser requires the dedicated 208/230V circuit. Always follow local electrical code and the installation manual.

Can this system be expanded later?

No. This is a single-zone mini split system and is designed to serve one indoor air handler. If you need to condition multiple rooms, choose a MRCOOL DIY multi-zone system instead.

What size room will this 12K Hyper Heat mini split cover?

This 12,000 BTU system is designed for spaces up to approximately 550 sq. ft. Actual sizing depends on insulation, ceiling height, layout, window exposure, climate zone, and other building conditions.

Does this bundle include the line set?

Yes. This complete bundle includes a 25 ft QuickConnect® pre-charged line set.

Can this system run on 115V power?

No. This is a 208/230V system and must not be connected to a 115V circuit or paired with 115V air handlers.

Why Buy From MRCOOL DIY Direct?

MRCOOL DIY Direct specializes in MRCOOL DIY systems, Hyper Heat mini splits, QuickConnect® line sets, accessories, parts, and support. Our team can help verify system sizing, electrical requirements, line set length, installation layout, and compatibility before you order.

Getting the right mini split the first time matters. Ordering the wrong voltage, wrong line set, or wrong system type is not “part of the adventure.” It is just expensive nonsense in a cardboard box.