MRCOOL built its reputation on systems you can install yourself. The 5th Gen 24K BTU unit continues that mission, but its real advantage is the new R-454A refrigerant. This is a lower-global-warming-potential gas that meets upcoming regulatory standards. You’re buying a system designed to remain compliant for years.

With a 22.7 SEER rating and Energy Star certification, it efficiently handles spaces up to 1,050 square feet. In practice, that means it can quietly maintain temperature in a large living area or open-concept floor plan without dramatic spikes in your energy bill. The included 25-foot pre-charged line set is the key to the DIY claim, eliminating the need for a professional vacuum pump or refrigerant handling during installation.

The build quality is solid, with a corrosion-resistant gold fin coil on the condenser. Be realistic about the DIY aspect, however. You still need to correctly mount both units, run electrical, and handle the line-set connections. It simplifies the hardest part, but it’s a full-day project for a confident homeowner.