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MRCOOL® HyperHeat®

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 Mini Split System – 5th Gen Wall Mount, -22°F Heating, 23.5 SEER2, Pre-Charged Line Set

SKUMC-DIY-HH12-WM-25

TypeSingle Zone Mini Split System

Regular price $2,557.00
Sale price $2,557.00 Regular price $2,914.98
You Save: $357.98
SALE Sold out
Shipping calculated at checkout.

Refrigerant Type: R-454B

Line Set Length
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PRODUCT DESCRIPTION

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

Performance
Cooling / Heating Capacity 12,000 BTU
Max Coverage Up to 550 sq. ft.
SEER2 23.5
HSPF2-4 10
HSPF2-5 8
EER2 12.8
Inverter Yes — DC rotary compressor
Min Ambient Heat -22°F
Min Ambient Cool -22°F
Noise Level 56.5 dB
Electrical
Voltage 208/230V
Phase 1
Maximum Fuse / Breaker 15 A
Minimum Circuit Ampacity 15 A
Refrigeration & Piping
Refrigerant Type R-454B (pre-charged)
Line Set Length (Included) 25 ft QuickConnect®
Max Line Set Length 75 ft
Liquid Line Size 1/4"
Suction Line Size 3/8"


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

Performance & Features
Cooling / Heating Capacity 12,000 BTU
Recommended Room Size Up to 550 sq. ft.
Mounting 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 Controls
WiFi Enabled Yes
App Control MRCOOL SmartHVAC™ App (iOS / Android)
Voice Control Amazon Alexa & Google Assistant compatible

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.

Rated 4.7 / 5 Stars
4700+ Verified Reviews

Comfort That Speaks for Itself

See why homeowners and pros alike trust MRCOOL DIY systems to deliver comfort, savings, and easy installation.

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee

I never thought I’d install my own HVAC system, but MRCOOL made it possible. The instructions were easy, and the pre-charged lines saved me from hiring a tech. Cools my garage workshop perfectly!

Jason R., North Carolina

Our MRCOOL mini-split runs really quiet — you can barely tell it’s on. Our electric bill dropped about 35% this summer. Very impressed with the efficiency

Megan L., Arizona

Installed this in my detached office. Took me a Saturday morning and a friend to lift the outdoor unit. Works flawlessly — heats in winter and cools in summer.

Daniel P., Texas

I swapped my old central unit for two MRCOOL DIY mini-splits. Same comfort, way lower bills. The inverter technology really makes a difference.

Jennifer C., Florida

Had a small question during installation and Vanessa picked up right away. They walked me through it step by step — best customer service I’ve had in years.

Chris B., Ohio

Keeps our sunroom comfortable in 100°F summers and comfy in the winter. The heat pump feature is amazing — one system for both heating and cooling!

Angela K., Kentucky

I’ve remodeled a few homes, and MRCOOL DIY systems are a game-changer. No need for HVAC pros or special tools — everything is plug-and-play.

Brandon S., Tennessee