MRCOOL DIY 18K Hyper Heat Mini Split System – 5th Gen, -22°F Heating, 21.2 SEER2, Pre-Charged DIY Line Set

MRCOOL DIYHH-18 Hyper Heat 18K Mini Split System with Wall Mount Air Handler

The MRCOOL® DIYHH-18 Hyper Heat 18K Mini Split System is a 5th Generation DIY ductless heat pump designed for homeowners who need reliable heating and cooling in true cold-climate conditions. This complete 18,000 BTU single-zone bundle includes the DIYHH-18 outdoor condenser , the DIY-18-HP-WMAH-230D25-O wall-mounted air handler , a 25 ft QuickConnect® pre-charged line set , and the required DIYPRO® cable.

Built for extreme winter performance, this MRCOOL Hyper Heat system provides dependable heating operation down to -22°F while also delivering efficient cooling for spaces up to 800 sq. ft. It is ideal for garages, bonus rooms, bedrooms, basements, offices, cabins, workshops, detached buildings, and other spaces where standard mini splits may struggle in colder weather.

Unlike traditional ductless mini split systems, the MRCOOL DIY series uses factory-sealed No-Vac® QuickConnect® pre-charged line sets filled with R-454B refrigerant . That means no vacuum pump, no gauges, no nitrogen purge, no refrigerant charging, and no HVAC certification required for the line set connection. Because apparently HVAC finally decided homeowners deserve one system that does not require a tool cart the size of a small moon.

What's Included in This Complete DIY Bundle?

DIYHH-18-HP-C-230D25-O – 18K Hyper Heat Outdoor Condenser, 208/230V

DIY-18-HP-WMAH-230D25-O – 18K Wall-Mounted Air Handler

DIY25-1412 – 25 ft Pre-Charged QuickConnect® Line Set

• DIYPRO® Cable

• Wireless Remote

• Installation Manuals

• Mounting Hardware

Why Choose the MRCOOL DIYHH-18 Hyper Heat?

• True cold-climate Hyper Heat performance down to -22°F

• 18,000 BTU heating and cooling capacity

• Designed for spaces up to 800 sq. ft.

• DIY-friendly No-Vac® QuickConnect® installation

• No vacuum pump, gauges, nitrogen, or refrigerant handling required

• Factory pre-charged R-454B refrigerant line set included

• Efficient inverter rotary compressor technology

• Up to 21.2 SEER2 efficiency

• Built-in smart control with MRCOOL SmartHVAC App

• Compatible with Amazon Alexa® and Google Assistant®

• Quiet indoor operation as low as 19 dBA