MRCOOL

MRCOOL is the brand that made true do-it-yourself mini splits mainstream, and it's our best seller. The DIY 5th Gen line reaches 23.6 SEER2, heats down to -13°F (-22°F on Hyper Heat models), runs as quietly as 19 dB, and carries a 7-year compressor / 5-year parts warranty when registered. For pro-installed ductless and central ducted systems, the Advantage, Universal, Hyper Heat and VersaPro lines cover everything from a single bedroom to a whole house.

The 5th Gen moved to R-454B refrigerant, added the DIYPRO® communication cable between the air handler and condenser, runs quieter (as low as 19 dB), and updated efficiency and controls with the SmartHVAC app. The 4th Gen used R-410A and is being phased out. Because the refrigerants differ, 4th Gen and 5th Gen condensers, air handlers and line sets are not cross-compatible — buy complete systems or components from the same generation.

Yes — that is what the DIY series is designed for. The line sets are pre-charged with quick-connect fittings, so there is no vacuum pump, refrigerant handling or EPA certification involved, and the factory warranty is valid with self-installation. Plan on a helper to lift the condenser, and have an electrician run the dedicated circuit and outdoor disconnect. Read the full walkthrough.

Start with 20–30 BTU per square foot: a 12K covers roughly 400–550 sq ft, an 18K 550–800 sq ft, a 24K 800–1,150 sq ft and a 36K up to about 1,550 sq ft. Add capacity for high ceilings, strong sun, kitchens and poorly insulated spaces. Use our sizing calculator for one room or the system builder for several — and our HVAC experts verify every system order for free.

Yes — every MRCOOL system on this page is a heat pump. DIY 5th Gen systems heat down to -13°F, and the DIY Hyper Heat and Central Ducted Hyper Heat lines are rated to -22°F for homes that rely on the heat pump as their primary heat source. In milder climates the Easy Pro (rated to 5°F) and Select lines are a good way to save.

A DIY system ships with the outdoor condenser, indoor air handler(s), pre-charged quick-connect line sets, remote(s) and mounting hardware. To finish the job you'll want an electrical kit (disconnect and whip), a condenser pad or wall bracket, and line-set cover to protect the lines outside — all available in our accessories collection. Here's the complete buying checklist.

Yes. We are an authorized MRCOOL dealer, so every system carries the full factory warranty — register it with MRCOOL after installation. DIY 5th Gen systems carry 7 years on the compressor and 5 years on parts when registered, with an extended limited-lifetime replacement option available through paid enrollment in the MRCOOL® Care program.