MRCOOL® DIY® 5th Gen E Star 12,000 BTU Single Zone Mini Split Complete System with 25ft. Line Set 115V — DIY-12-HP-WM-115D25-0

PRODUCT DESCRIPTION

MRCOOL DIY® 5th Gen ENERGY STAR® 12K BTU Single Zone Mini Split – The Ultimate DIY HVAC Solution

Take total control of your home’s heating and coolingwith the MRCOOL DIY® 5th Gen ENERGY STAR® 12,000 BTU Single Zone Mini-Split System. Engineered for easy, tool-free installation, this high-efficiency ductless heat pump is the perfect climate solution for rooms up to 550 sq. ft. Featuring eco-friendly R-454B refrigerant, advanced inverter technology, and smart home integration, this system delivers powerful heating and cooling performance while reducing energy consumption and lowering utility costs.

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Revolutionary DIY Installation – No HVAC Technician Needed

Say goodbye to expensive HVAC installation costs! The MRCOOL DIY® Mini Split features a patented QuickConnect® pre-charged line set, allowing homeowners to install the system themselveswithout special tools, vacuum pumps, or professional assistance.

• DIYPRO® Cable – Provides enhanced safety, durability, and eliminates the need for electrical conduit.
• No Vacuuming Required – Pre-charged refrigerant lines ensure a hassle-free setup.
• Step-by-Step Installation Guide & Video Support – Everything you need to install with confidence.

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Superior Energy Efficiency & Eco-Friendly R-454B Refrigerant

The MRCOOL DIY® 12K BTU mini split is ENERGY STAR® certified, ensuring maximum efficiency and cost savings. It utilizes R-454B refrigerant, which has a significantly lower Global Warming Potential (GWP) than R-410A, making it an environmentally responsible choice for homeowners looking to reduce their carbon footprint.

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Smart Home Integration – Total Climate Control at Your Fingertips

Experience ultimate convenience with multiple control options that let you adjust your indoor climate anytime, anywhere:

✔ Wireless Remote Control – Adjust temperature, fan speed, and modes with ease.
✔ SmartHVAC App (iOS & Android) – Control your system remotely via smartphone.
✔ Amazon Alexa & Google Assistant Compatible – Enjoy voice-activated climate control.
✔ Follow Me® Function – Sensors in the remote detect your location to maintain consistent comfort.
✔ Dry Mode Dehumidification – Removes excess moisture for improved indoor air quality.

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Built for Durability & All-Season Performance

Designed to withstand extreme weather conditions, the MRCOOL DIY® Mini Split features a Gold Fin® Condenser that provides superior corrosion resistance—ideal for coastal climates and long-term durability.

• Reliable Heating & Cooling – Works efficiently in both hot summers and cold winters.
• Quiet Operation – Ultra-low noise levels ensure uninterrupted comfort.
• Intertek Certified (5031495) – Rigorously tested for safety, efficiency, and performance.

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Industry-Leading Warranty for Peace of Mind

MRCOOL backs the 5th Gen DIY® Mini Split with an industry-best warranty, ensuring long-term reliability:

✔ 7-Year Compressor Warranty
✔ 5-Year Parts Warranty

WHAT'S INCLUDED

1 condenser  DIY-12-HP-C-115D25-O                                 (25ft line set with condenser)

1 wall mount air handler  DIY-12-HP-WMAH-115D25-O (com wire is with the air handler)

1 Remote and WiFi USB.                                                     (boxed with air handler)

Smart Phone NOT included.

SPECIFICATIONS & DIMENSIONS

Dimensions & Weight
Condenser Dimensions	30.12 W" x 11.93 D" x 21.85 H"
Air Handler Dimensions	31.57 W" x 7.44 D" x 11.69 H"
Condenser Weight	65.48 lbs / 29.7 kg
Air Handler Weight	24.91 lbs / 11.3 kg
Capacity & Performance
Zone Capacity	1
Cooling Capacity	12,000 BTU
Outdoor Operating Temperature (Cooling)	-13°F - 122°F
EER2	12.5
SEER2	23.5
Heating Capacity	12,000 BTU
Outdoor Operating Temperature (Heating)	-13°F - 75°F
HSPF2-4	10.2
HSPF2-5	7.6
Coverage Area	350 to 500 sq ft.
Outdoor Noise Level	54 dB(A)
Indoor Noise Level (Hi/Mi/Lo)	43.0/39.5/33.5/24.0/18.0 dB(A)
Electrical Requirements
Voltage	115V
Phase	1
Cycle	60 Hz
Max Fuse Breaker	20A
Min Circuit Ampacity	18A

 

Refrigerant & Piping
Refrigerant Type	R-454B
Refrigerant Volume	30.34 oz
Liquid Line Size	1/4"
Suction Line Size	3/8"
Max Line Set Length	82 ft.
Features
Inverter	DC
Compressor Type	Rotary
Fan Only Option	Yes
Quiet Mode	Yes
Auto Cool	Yes
Wifi Compatibility	Yes
App Compatibility	Yes
Works with IOS	Yes
Works with Android	Yes
Remote Control Included	Yes
Certifications & Warranty
Certifications	UL Listed, ETL Listed, Energy Star Certified, AHRI Certified
Warranty	7 Years Compressor 5 Years Parts

Frequently Asked Questions

What's the difference between the 5th Gen and 4th Gen?

The 5th Gen MRCOOL DIY® Mini Split offers several key upgrades over the 4th Gen, focusing on efficiency, advanced technology, and eco-friendliness.

Here’s what’s new with the 5th Gen:

• Next-Gen R-454B Refrigerant: A more environmentally friendly refrigerant with lower global warming potential (GWP), compliant with the latest HVAC regulations.
• Higher Energy Efficiency: Improved SEER2 ratings for greater energy savings and optimized performance.
• Enhanced System Reliability: Upgraded components for better heating and cooling performance.
  
  

Can I install it myself, or do I need a professional?

The MRCOOL DIY system is designed for homeowners and doesn’t require HVAC tools. You can install the indoor and outdoor units yourself using the pre-charged Quick Connect® lines. However, a licensed electrician is required for the electrical hookup to ensure safety and code compliance.

Does it work in cold weather?
Yes. MRCOOL 5th Gen systems feature low-ambient heating and can provide reliable heat even when outdoor temperatures drop to around 5°F.

How do I know what BTU size I need for my rooms?

A general rule of thumb is 20 BTU per square foot of space. Here's a rough guide:

• 6,000 BTU = 100 - 150 sq ft
• 9,000 BTU = 150 - 350 sq ft
• 12,000 BTU = 351- 500 sq ft
• 18,000 BTU = 501 – 750 sq ft
• 24,000 BTU = 751 – 1,000 sq ft
• 36,000 BTU = 1,001 - 1,500 sq ft

Some additional factors may impact performance such as insulation, ceiling height, sun exposure and the number of appliances in the room. For assistance, contact our Product Experts

Does it heat as well as cool?

Yes. All 5th Gen models are heat pumps, providing both heating and cooling for year-round comfort.

Is it Wi-Fi compatible?

Yes. The MRCOOL SmartHVAC app allows smartphone control and works with Amazon Alexa and Google Assistant.

What is the warranty?

The MRCOOL 5th Generation DIY Mini-Split systems offer the following warranty coverage:

• 7-Year Compressor Replacement Warranty: This warranty ensures that if the compressor fails within the first seven years, MRCOOL will provide a replacement.
• 5-Year Parts Warranty: This warranty covers all parts of the system for five years from the date of purchase.

Recommended Room Types

Perfect for:

• Bedrooms
• Home offices
• Small living rooms
• Tiny homes
• Garages
• Bonus rooms
• Apartments
• Sunrooms

Why Buy from MRCOOL Direct?

As the USA’s most trusted #1 MRCOOL Authorized dealer, we provide:

✅ Factory-Direct Pricing – Get the best deals on MRCOOL HVAC systems.
✅ Fast, Secure USA Shipping – Get your mini split quickly and safely delivered.
✅ Expert DIY Support – Our team helps you every step of the way.

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Upgrade to the MRCOOL DIY® 5th Gen 12K BTU Mini-Split – The Easiest & Most Efficient Way to Heat & Cool Your Space Year-Round!

Order now and enjoy powerful, energy-efficient climate control with a system designed for easy installation and long-lasting performance.

 

MRCOOL® 5th Gen DIY vs Easy Pro™ 5th Gen — Which Mini-Split Is the Better Choice?

When you’re investing in a ductless mini-split system, you’re not just buying equipment—you’re buying comfort, reliability, energy savings, and warranty protection for the next decade or more.

MRCOOL® gives homeowners two powerful options: the 5th Generation DIY Series and the Easy Pro™ 5th Gen Series.

Both are designed to simplify installation and deliver efficient year-round comfort, but they are built for different types of customers and use cases.

Below is a straight-forward, expert breakdown so you can choose the system that fits your home, budget, and expectations.

 

 

1. Installation: DIY Game-Changer vs Semi-DIY Convenience

 

MRCOOL® 5th Gen DIY — The Only True DIY Mini-Split

The 5th Gen DIY is the industry-leading* self-installation mini-split system.

It uses MRCOOL’s pre-charged QuickConnect® line sets, filled at the factory with R-454B refrigerant.

• No vacuum pumps
• No gauges
• No refrigerant handling
• No HVAC license

Simply connect, tighten, and you’re done.

This technology is why the DIY Series is unmatched in the entire HVAC market.

Comes standard with:

• 25 ft QuickConnect® line set (extendable)
• R-454B refrigerant pre-charged
• Tools-free refrigerant system

This system can be installed in about 3–5 hours with common household tools.

MRCOOL® Easy Pro™ 5th Gen — Easier Than Traditional Systems

The Easy Pro™ uses a 16 ft Fast Connection pre-charged line set, also using R-454B.

This makes Easy Pro ideal for:

• Apartments
• Rental properties
• Light commercial installs
• Homeowners who want professional sign-off

Bottom line:

• DIY 5th Gen = No HVAC professional required
• Easy Pro 5th Gen = Very simplified install, but requires a technician

2. Energy Efficiency: The 5th Gen DIY Wins

Both systems are efficient, but the 5th Gen DIY is the performance champion.

5th Gen DIY 9K BTU

• 23.6 SEER2
• One of the most efficient ductless DIY systems available today
• Lower monthly energy use = lower operating cost for life of the unit

This matters in real dollars:

• More comfort for less energy
• Better humidity control
• Faster heating and cooling
• Higher performance in extreme climates

Easy Pro 9K BTU

• 20.2 SEER2
• Still excellent vs traditional mini-splits
• Ideal for moderate climates and budget installations

Efficiency takeaway:

If you want the lowest energy bills, the 5th Gen DIY is the clear winner.

 

3. Warranty Protection: The Biggest Difference

Here’s where MRCOOL separates casual systems from premium investment-grade HVAC.

MRCOOL® 5th Gen DIY Warranty

• 7-Year Compressor
• 5-Year Parts

This is industry-defining coverage—unmatched by any competitor in the DIY space.

It shows MRCOOL’s confidence in the engineering of their flagship product.

MRCOOL® Easy Pro Warranty

• 2-Year Compressor
• 1-Year Parts
• Registration required

It offers solid protection, but nowhere near the level of the DIY Series.

If long-term reliability matters to you — choose 5th Gen DIY.

4. Smart Features & App Control

Both systems deliver advanced comfort, but the 5th Gen DIY includes more premium features.

5th Gen DIY:

• Voice control (Alexa / Google Assistant)
• Follow Me comfort sensor
• Advanced inverter technology
• Higher cold climate performance
• Better humidity and noise reduction

Easy Pro:

• Quiet operation
• Basic app and smart features
• Excellent temperature stability

If you want technology that feels luxury, the DIY Series is a step above. 

5. Line Set Length: Flexibility Matters

Space planning is a real-world problem.

DIY 5th Gen

• Standard 25 ft
• Expandable with extensions
• Perfect for multi-room or attic/basement runs
• Great for coastal or large properties

Easy Pro

• Standard 16 ft
• Fits small rooms, garages, and simple layouts

Longer lines = more flexibility and fewer compromises.

Which One Should You Choose?

 Choose MRCOOL® 5th Gen DIY if you want:

• True homeowner installation — no HVAC tech required
• 23.6 SEER2 efficiency or higher
• Lower monthly energy bills
• Stronger long-term reliability
• 25 ft line set flexibility
• Premium smart features
• Coastal-grade durability

This is the flagship MRCOOL system.

If you want the best performance and future-proof value, choose DIY 5th Gen.

 

Choose MRCOOL® Easy Pro if you want:

• MRCOOL quality at a lower entry price
• If you want shorter line lengths (16 ft)
• A simpler installation than traditional systems
• Quiet comfort without high-end features
• Solid performance for smaller rooms or secondary spaces
• You plan to use a professional installer

This is the budget-friendly way to get MRCOOL performance.

The Bottom Line

Both the MRCOOL® Easy Pro™ and 5th Gen DIY mini-splits deliver real comfort, inverter technology, and simple installation.

But they are not the same class of product:

• MRCOOL® 5th Gen DIY = Premium performance, best-in-class efficiency, and industry-leading warranties.
• MRCOOL® Easy Pro™ = A more affordable way to upgrade comfort with simplified installation.

 

If you want maximum efficiency, reliability, smart features, and the strongest warranty in HVAC, the 5th Gen DIY stands alone.

If you need solid performance at a lower cost, and you don’t mind a less warranty protection, the Easy Pro is the perfect fit.

Need help sizing the right capacity (9K, 12K, 18K, 24K+)?

Call us MRCOOL DIRECT we’ll get you matched correctly—fast, accurate, and homeowner-friendly.