Line sets, explained in five minutes
The line set is the pair of insulated copper lines that carries refrigerant between the outdoor unit and each indoor unit. On a Status mini split they arrive factory pre-charged and sealed, with Quick Connect fittings. Choose the correct gauge and length for your system and follow the manufacturer's routing instructions: you pick the length up front, and you can't trim it.
Measuring: route, not distance
Measure the path the line will actually travel (out through the wall, down, along the foundation, around the corner to the outdoor unit), never the straight line through the house. Add the ups and overs. Then round up to the next offered length: 15, 25, 40, 55, or 70 feet. A few feet of slack coils neatly behind the outdoor unit; a line set two feet short ends the weekend.
Gauges are matched to indoor units, automatically
Smaller indoor units (9K and 12K) use 1/4″ × 3/8″ lines; the 18K indoor unit uses 1/4″ × 1/2″. You don't need to remember this: each product page only offers the correct gauge for each zone, so a mismatch can't be ordered.
Routing rules of thumb
- Gentle curves, never kinks: treat the line like a garden hose you can't replace.
- Support long horizontal runs every few feet so the insulation doesn't sag.
- Slope the drain (the third, humble hose) continuously downhill; condensate has no pump.
- Outside, a paintable cover kit hides the run and protects the insulation from sun.
The “None” option
Every zone can be ordered without a line set. That exists for renovations and staged projects (a zone you'll finish next season) and for pros with stock. If you're ordering your first mini split for immediate install, every zone you plan to run needs a line set, each of which includes its install kit.
Unsure between two lengths after measuring? Send us a photo of the route; it's a thirty-second answer.