MRCOOL DIY 18K BTU Wall-Mounted Air Handler | Indoor Unit for Larger Rooms up to 800 Sq. Ft.

Power your large living spaces with the 5th Generation MRCOOL® DIY® 18K BTU Air Handler. This high-capacity, wall-mounted indoor unit delivers robust heating and cooling for large rooms, master suites, and open-concept areas up to 800 sq. ft. Engineered for a true DIY installation, it connects seamlessly to a compatible outdoor condenser with no special tools or HVAC experience required. Enjoy professional-grade comfort on your own terms.

Why This High-Capacity DIY Indoor Unit Is Ideal for You

✅ High-Power Comfort for Large Spaces: With 18,000 BTU of capacity, this unit efficiently manages climate control in larger areas where standard units fall short—perfect for great rooms, large bedrooms, or converted garages.

✅ QuickConnect® for Hassle-Free Installation: Designed exclusively for the MRCOOL DIY ecosystem. The pre-charged, 25-foot QuickConnect® line set (sold separately) allows for a vacuum-free, tool-simple connection, eliminating the most complex step of traditional mini-split setup.

✅ Integrated DIYPRO® Electrical System: The included DIYPRO® cable combines power and control wiring into one durable, weather-resistant line. It removes the need for separate metal conduit, simplifies the electrical run, and provides superior protection against the elements and pests.

✅ Total Control at Your Fingertips: Operate your system effortlessly. Choose from the included wireless remote, the intuitive SmartHVAC app for iOS/Android for control from anywhere, or convenient voice commands via Amazon Alexa and Google Assistant.

Advanced Features for Whole-Room Comfort

• Follow Me Technology: The remote control doubles as a personal thermostat. Enable this feature, and the air handler will detect the remote's location and direct airflow to maintain consistent, personalized comfort right where you are.

• Dry Mode for Humidity Control: More than just cooling; this mode acts as a dedicated dehumidifier to remove excess moisture from the air. It enhances comfort on muggy days and helps prevent mold and mildew growth.

• Quiet, High-Volume Airflow: Engineered to move large volumes of air quietly and efficiently, ensuring even temperature distribution throughout your entire space without disruptive noise.

Built for Durability & Backed by Strong Warranties

• Pairs with Gold Fin® Condensers: For maximum durability, especially in challenging environments, pair this air handler with an outdoor unit featuring Gold Fin® anti-corrosion technology—ideal for coastal homes or regions with high humidity.

• Warranty You Can Trust: Your investment is protected by MRCOOL's comprehensive warranty package. This indoor unit is covered by a 5-year parts warranty, supported by the full system's 7-year compressor warranty and limited lifetime warranty on the outdoor coil.

Specifications & Details

• Product: Indoor Air Handler (Wall-Mounted Unit) | 5th Generation

• Capacity: 18,000 BTU (Requires a matching 18K BTU outdoor condenser)

• Recommended Coverage: Large rooms up to 800 sq. ft.

• Connection System: QuickConnect® compatible (uses R-454B refrigerant in lineset)

• Electrical: DIYPRO® Cable ready (included)

• Control: Wireless Remote, SmartHVAC App, Voice Control (Alexa/Google Assistant)

• Key Modes: Cooling, Heating, Fan, Dry (Dehumidify), Auto

• Special Feature: Remote "Follow Me" Temperature Sensing

• Warranty: 5-Year Parts Warranty (on this indoor unit)

What's Included & What You Need

This listing includes: The 18K BTU indoor air handler, wireless remote, and DIYPRO® cable.

To create a complete DIY mini-split system, you will need:

• A compatible MRCOOL DIY 18K BTU Outdoor Condenser (5th Gen recommended) 

• A MRCOOL DIY QuickConnect® Pre-Charged Line Set (25ft standard or other required length)

Ready to take control of your large space? The MRCOOL DIY 18K BTU Air Handler combines high power, smart features, and DIY simplicity for ultimate comfort. Add to your cart and complete your system with the outdoor condenser and lineset.

🔗 Need the entire system? For your convenience, shop our MRCOOL DIY 18K BTU Complete System Bundle, which includes the indoor air handler, outdoor condenser, and pre-charged lineset in one ready-to-install kit.