1.5 Ton DIY Mini Split: 18,000 BTU DIY Systems You Install Yourself by Zone Air
Updated July 5, 2026
A 1.5 ton DIY mini split is an 18,000 BTU ductless heat pump mini split, sized for larger spaces up to about 800 sq ft like great rooms, open-plan main floors, basements, and ADUs. Zone Air’s 1.5-ton systems are pre-charged and quick-connect, so you install it yourself with no vacuum pump and no HVAC contractor.
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Is a 1.5 Ton (18,000 BTU) DIY Mini Split Right for You?
Zone Air’s 18,000 BTU (1.5-ton) DIY mini split runs on 230V, is rated 23.5 SEER2, covers up to 900 sq ft, and heats down to -13°F in 2026. One and a half tons equals 18,000 BTU of heating and cooling. At roughly 20 BTU per sq ft, a 1.5-ton system covers a space of about 600–800 sq ft — great rooms, large open floors, and finished basements. For a single open volume this is often the largest single-head size you’ll need.
Conditioning more than one room? Instead of one oversized head, a dual-zone or multi-zone system gives each room its own thermostat. Need less? See 1 ton (12,000 BTU).
Get Your 1.5 Ton DIY Mini Split System
Every Zone Air 18,000 BTU system in 2026 ships with a pre-charged R-454B quick-connect line set, WiFi control, a 30 dB quiet mode, and a 5-year parts / 7-year compressor warranty, and Zone Air averages 4.8/5 across 133 verified reviews. Browse Zone Air’s 18,000 BTU systems, or size your space first with the free calculator.