Ductless heating and cooling, explained
Ductless heating and cooling: one system, both directions. Only 2 brands skip the vacuum pump; the rest need a licensed pro despite pre-charged claims.
verified Aug 2026 · 10 minDIY mini split heat pumps, without the guesswork
Which unit fits your space, whether you can really install it yourself, and where DIY ends. Verified specs, dated prices.
MRCOOL DIY 5th Gen 18kTRUE-DIY
Cooling, rated18,000 BTU/h
Heating at 5°F, max12,800 BTU/h
SEER222.5
Circuit230V · 20A max breaker
All figures verified Aug 2026 · How we verify
Start here
All guidesWhat is a mini split?
A mini split is a heat pump in two parts: an indoor head on your wall and an outdoor unit, joined by a refrigerant line set through one small hole. It heats and cools the room it is in, with no ducts.
Read the full guideWhy choose a mini split?
An inverter-driven unit runs at part speed most of the time. That is why a SEER2 rating in the 20s shows up as a lower bill than a window unit or baseboard heat. They are not right for every home. A leaky house or a deep cold snap can outrun a standard unit.
Read the full guideHow do you install a mini split?
It depends on the unit. Quick-connect line sets are a weekend job. Flare fittings need a vacuum pump and a micron gauge. DIY ends at two points: opening a refrigerant circuit, and the 240V breaker and whip, which belong to an electrician.
Read the full guideEvery spec and price on this site is checked against a primary document and dated on the page. How we verify
Can you actually DIY a mini split?
Every unit we cover gets one of three tiers. The tier describes the refrigerant line set and the warranty's install clause, never your confidence level.
TRUE-DIY
Quick-connect line sets
Pre-charged fittings, no vacuum pump, and the warranty explicitly allows owner install. A careful owner installs one in a weekend; the 240V circuit is usually the only step to hand off.
Typical: MRCOOL DIY, Zone Air
VACUUM REQUIRED
Flare fittings + vacuum
Needs a vacuum pump, micron gauge, and torque wrench, whatever the listing claims. Doable, but a bad flare is the #1 leak point, and most warranties want proof of evacuation.
Typical: Senville, Pioneer, Cooper & Hunter
PRO INSTALL ONLY
Pro-install only
DIY install voids the warranty outright. The best cold-climate performance lives here, and the premium buys an installer network as much as hardware.
Typical: Mitsubishi, Daikin, Fujitsu
Latest guides
All guidesHow long do mini splits last? By brand and tier
How long do mini splits last? Compressor warranties run 5 to 12 years by brand, and install quality decides which end of that range you land on.
verified Aug 2026 · 9 minMini split vs central air: cost, ducts, the verdict
Mini split vs central air by house situation: installed cost from two sources each side, and the 20-30% duct loss central air pays that a mini split never does.
verified Aug 2026 · 9 minDo mini splits heat and cool? Capacity at 5°F
Yes, mini splits heat and cool one room. A cold-climate model 'rated to −22°F' still loses over half its nameplate there, verified against NEEP.
verified Aug 2026 · 7 minMini split for attic or upstairs: sizing, placement
Upstairs rooms run hotter and colder than the floor below, and a sloped ceiling changes the load. Sizing, head placement, and line-set routing, verified.
verified Aug 2026 · 8 minMini split for mobile home: HUD Code panel limits
HUD Code caps a manufactured home's power supply at 50A, often less than a modern panel carries. The electrical math, insulation, and DIY tiers, verified.
verified Aug 2026 · 9 minWhat size mini split do you need?
Five inputs: square footage, ceilings, insulation, climate zone, sun. About a minute, and the result is never gated behind an email.
Open the sizing calculator
A screening estimate; we tell you when your space needs a Manual J instead.