Experience simplified home comfort with the MRCOOL® DIY® 5th Generation 12k BTU Ductless Mini-Split Heat Pump System. With a 23.5 SEER efficiency rating, this single-zone system delivers powerful heating and cooling for rooms up to 550 sq. ft.—all without requiring professional installation or specialized tools.

The system includes a 25-foot pre-charged QuickConnect® line set containing eco-friendly R-454B refrigerant, allowing for a fast, vacuum-free installation. Also included is the rugged DIYPRO® cable, designed to replace traditional electrical conduit and withstand harsh outdoor conditions, animals, and yard equipment.

Multiple control options make operation effortless—use the included remote, the SmartHVAC app on iOS or Android, or enable voice control with Amazon Alexa or Google Assistant. The unit’s Gold Fin™ anti-corrosion coating adds enhanced durability, especially in coastal and humid climates.

Packed with intelligent features like Auto Mode, Timer functionality, and Auto Restart after a power outage, this system is built to deliver efficient, hands-off climate control all year round.

Protected by an exceptional warranty—limited lifetime on select components, 7 years on the compressor, and 5 years on parts—this mini-split is engineered for long-lasting performance and peace of mind. The MRCOOL® DIY® 12k BTU system combines innovative technology, reliable comfort, and true do-it-yourself convenience.

Key Features

• True DIY Installation – No specialized tools or HVAC experience required. Pre-charged QuickConnect® line set allows for fast, secure setup.

• High Efficiency Performance – Achieves up to 23.5 SEER and 10.2 HSPF, delivering dependable year-round comfort with reduced energy costs.

• Smart Control Integration – Operate via remote control, SmartHVAC app (iOS/Android), or voice through Amazon Alexa and Google Assistant.

• Gold Fin™ Corrosion Protection – Protects against salt and moisture buildup, extending unit lifespan in coastal or humid environments.

• Durable DIYPRO® Cable – Replaces standard conduit, providing enhanced protection against animals, weather, and lawn tools.

• Follow Me® Function – Remote control monitors temperature around you to ensure personalized comfort.

• Auto Restart – Automatically resumes operation with previous settings after power outages.

• Advanced Timer & Auto Modes – Program your ideal temperature schedule or let the system adjust automatically for optimal comfort.

• Backed by Industry-Leading Warranty – Includes a limited lifetime warranty, 7-year compressor warranty, and 5-year parts warranty.

Specifications

• Brand: MRCOOL®

• Series: DIY 5th Generation

• Product Type: Single-Zone Ductless Mini-Split Heat Pump

• Bundle Includes:

  • 12k BTU Condenser

  • 12k BTU Wall-Mounted Air Handler

  • 25 ft. Pre-Charged QuickConnect® Line Set

  • DIYPRO® Cable

  • Wireless Remote

• Model Number: DIY-12-HP-WM-115D25-O

• UPC: 840255588546

• Voltage: 115V, 1 Phase, 60 Hz

• SEER Rating: 23.5

• EER Rating: 12.5

• HSPF Rating: 10.2

• Cooling Capacity: 12,000 BTU

• Heating Capacity: 12,000 BTU

• Coverage Area: Up to 550 sq. ft.

• Airflow (CFM): 400

• Compressor Type: Rotary

• Fan Speeds: Variable

• Dehumidification Rate: 1.0 liters/hour

• Refrigerant Type: R-454B (pre-charged)

• Line Set Length: 25 ft.

• Liquid Line Size: 1/4"

• Suction Line Size: 3/8"

• Color: White

• Mount Type: Wall-Mounted

• Control Options: Remote, SmartHVAC App, Amazon Alexa, Google Assistant

• Sound Rating (Indoor): 23–41 dB

• Sound Rating (Outdoor): 54 dB

• Dimensions (Indoor Unit): 30.34” W x 7.44” D x 10.83” H

• Dimensions (Outdoor Unit): 30.34” W x 11.81” D x 21.85” H

• Weight (Indoor/Outdoor): 18 lbs / 54 lbs

• Certifications: Intertek Listed (5031495)

• EnergyGuide & AHRI Certified

• Warranty:

  • Parts: 5 Years

  • Compressor: 7 Years

  • Limited Lifetime Warranty: Yes (registration required)

• Environmentally Friendly: Yes – R-454B low-GWP refrigerant

• Reusable Components: Yes

• Auto Restart: Yes

• Timer Function: Yes

• Indoor Display: Yes

• Indoor Unit Finish: Glossy white

• Warranty Registration Required: Yes

BTU Size Chart

Which BTU rating should I choose?

• The appropriate BTU rating depends on the size of the space you need to heat or cool.
• A higher BTU indicates greater heating and cooling capacity, allowing the air handler to effectively condition larger areas.

*Ceiling height, insulation quality, and local climate can all affect the actual coverage area. For instance, an uninsulated space will need more BTUs to maintain comfort compared to a well-insulated room.

Shipping & Returns

Shipping Policy

• Free Shipping on All Orders – We provide free standard delivery on all orders within the contiguous U.S.

• Ground Shipping for Smaller Items – Accessories and lighter products ship via standard ground carriers such as FedEx, UPS, or similar.

• Freight Delivery – Large items (HVAC/Heaters) ship via LTL freight. Drivers deliver to the curbside only; they cannot bring items into your home or garage.

• Tracking Information – Tracking is typically provided within 3–5 business days after your order is placed.

• Carrier Updates – Once tracking is issued, allow 1–2 business days for the carrier to populate shipment details.

• More Information – Full details can be found on our Shipping Policy page.

Return Policy

• 30-Day Return Window – Return requests must be submitted within 30 days of delivery; requests after this period cannot be accepted.

• Inspect Upon Delivery – Visible damage must be noted on the driver's paperwork. Report all damage within 24 hours to qualify for a replacement.

• Return Condition Requirements – Items must be unused, uninstalled, and in original packaging, including all boxes, crates, or pallets.

• Restocking Fees – Restocking fees of 25–35% apply to most brands; see full policy for details.

• Non-Returnable Items – Accessories, small components (remotes, line sets), and custom-finish items are non-returnable.

• Full Details – See our Return & Refund Policy page for complete guidelines.