MRCOOL DIY 5th Generation 18k BTU Heat Pump Mini Split - Complete System (454B Refrigerant)

MRCOOL DIY-18-HP-WM-115D25-O is a ductless heat pump mini-split designed for efficient, year-round climate control in spaces up to 800 sq. ft.The 5th Generation MRCOOL DIY line blends performance, durability, and true do-it-yourself installation. A pre-charged 25 ft. Quick Connect line set filled withR-454B refrigerant eliminates special tools and pro installation. The included DIYPRO cable replaces electrical conduit to protect wiring from weather, wildlife, and yardwork.

Multiple control options come standard: a wireless remote, the SmartHVAC app for iOS/Android, and hands-free voice control via Amazon Alexa andGoogle Assistant. After a power outage, the system automatically restores previous settings. A corrosion-resistant gold fin condenser boosts longevity—ideal for coastal environments—whileFollow Me temperature sensing and Dry mode fine-tune comfort and humidity. MRCOOL backs the system with a limited lifetime warranty, plus7 years on the compressor and 5 years on parts.

• 18,000 BTU heating & cooling capacity
• Covers areas up to 800 sq. ft.
• 25 ft. pre-charged Quick Connect line set with R-454B
• Gold fin condenser for corrosion resistance
• Control via remote, SmartHVAC app, Alexa, and Google Assistant
• Follow Me temperature sensing for personalized comfort
• Dry mode to reduce humidity
• Auto-restart restores previous settings after outages
• Limited lifetime warranty; 7-year compressor; 5-year parts
• Not compatible with R410A systems

Efficient climate control for small to medium spaces

With its 18K BTU capacity, this system delivers dependable heating and cooling for rooms up to 800 sq. ft. The environmentally forward R-454B refrigerant modernizes performance versus older blends.

DIY-friendly installation

The pre-charged Quick Connect line set streamlines installation—no vacuum pump required. The DIYPRO cable replaces traditional conduit for a cleaner, more durable setup.

Built for reliability and long service life

A gold fin condenser improves corrosion resistance in humid or coastal areas. Auto-restart ensures comfort resumes seamlessly after power interruptions.

Smart comfort features

Control from anywhere with the SmartHVAC app, or go hands-free with Alexa and Google Assistant. Follow Me uses the remote’s location for targeted temperature control, and Dry mode reduces excess humidity.