Goodman mini split line set sizes
Short answer: The Goodman mini split line set size is simple because the current E-Series only comes in three capacities: the 9,000 and 12,000 BTU units use a 1/4" × 3/8" line set, and the 18,000 BTU uses 1/4" × 1/2" — all flared, all R-410A. There's no 24k in the current single-zone line. One big caveat: if your "Goodman" is a central AC or heat pump (GSX/GLXS), it uses larger, brazed copper and none of this applies. Sizes here come from Goodman's own spec sheets and installation manuals; confirm yours before buying.
Goodman is best known for ducted central equipment, so most "Goodman line set" searches land on brazed 3/4" suction lines that have nothing to do with a mini-split. This page covers the ductless side — the current E-Series and the discontinued MS15 — pulled from Goodman's spec sheets, with the central-AC sizes noted so you can tell which system you actually have. Prefer to size by run length too? Use the size calculator.
Goodman E-Series line set size by capacity
Goodman is a Daikin Comfort Technologies brand, and the current E-Series ductless line (2024 and later) is a rebadged Daikin platform — the model numbers RXNG##AXVJU (outdoor) and FTXNG##AXVJU (indoor) follow Daikin's FTX/RX nomenclature. The sizing table is correspondingly short: three capacities, two line set sizes.
| Goodman E-Series size | Line set (liquid × suction) |
|---|---|
| 9,000 BTU | 1/4" × 3/8" |
| 12,000 BTU | 1/4" × 3/8" |
| 18,000 BTU | 1/4" × 1/2" |
Found your size? Get the matching line set
We stock both current Goodman E-Series sizes: 1/4" × 3/8" for the 9k and 12k, and 1/4" × 1/2" for the 18k — in 16 ft and 25 ft, open for preorder.
Have a Goodman central AC instead? Different copper entirely
Goodman central air conditioners and heat pumps — the GSX and GLXS condensers sitting outside most Goodman-equipped houses — are a different animal. They use a 3/8" liquid line with a 3/4" suction line at 1.5–2.5 tons, 7/8" at 3 tons, or 1-1/8" at 3.5–5 tons, the connections are brazed (sweat), not flared, and the factory charge covers 15 ft of line. If that's the unit you own, mini-split flared line sets don't apply — you need brazed-connection copper sized to your condenser, installed by someone with a torch and a nitrogen setup.
Goodman ductless series, current and discontinued
Goodman has only fielded two single-zone ductless generations, with a long gap between them.
| Series | Status | Capacities | Refrigerant | Line set sizes |
|---|---|---|---|---|
| E-Series (RXNG/FTXNG) | Current (2024+), Daikin platform | 9k, 12k, 18k | R-410A | 1/4" × 3/8" (9k–12k), 1/4" × 1/2" (18k) |
| MS15 (MSH/MSC) | Discontinued (~2013) | 9k, 12k, 18k, 24k (22k actual) | R-410A | 1/4" × 3/8" (9k–12k), 1/4" × 1/2" (18k), 3/8" × 5/8" (24k) |
Note what the table implies: the current line tops out at 18,000 BTU. If you're replacing a legacy MS15 24k, there's no like-for-like E-Series successor — and the 24k was the only Goodman mini-split to use a 3/8" liquid line. The MS15 shipped with a 16 ft line set in the box; the E-Series spec sheets don't list an included set, so plan on buying your copper.
Flared connections, and Goodman's length limits
E-Series units use standard field-flared connections, not pre-charged quick-connect — you cut, flare, and torque the nuts, then pull a vacuum before opening the service valves, which needs a vacuum pump and typically EPA 608 certification. The manual's limits are metric figures converted to feet, which is why they look oddly precise.
| Model | Max line length | Max vertical separation | Pre-charged for | Refrigerant adder |
|---|---|---|---|---|
| E-Series 9k–12k | 65-5/8 ft (20 m) | 32-13/16 ft (10 m) | 32-13/16 ft (10 m) | 0.21 oz/ft |
| E-Series 18k | 98-1/2 ft (30 m) | 32-13/16 ft (10 m) | 32-13/16 ft (10 m) | 0.21 oz/ft |
| MS15 9k–12k (legacy) | 66 ft | 26 ft | — | 0.2 oz/ft |
| MS15 18k (legacy) | 82 ft | 33 ft | — | — |
| MS15 24k (legacy) | 82 ft | 33 ft | — | 0.4 oz/ft |
Beyond the pre-charged length, add about 0.21 oz of refrigerant per extra foot on the E-Series — a gauges-and-scale job for an HVAC pro, not a guess. One thing worth flagging: some retailers list the E-Series pre-charge as covering "25 ft," but Goodman's installation manual gives the figure as 10 m (32-13/16 ft) — go with the manual. Goodman doesn't publish a minimum line length for the E-Series. If your run is longer than a stock length, buy the right length outright rather than coupling two sets — see our standard line sets, or pre-charged line sets if you want the no-vacuum route on a compatible system.
Refrigerant: still R-410A on the ductless side
Goodman's ducted central line has already moved to R-32 — the GLXS and GLZS condensers — but the ductless E-Series still sells as R-410A, and no R-32 ductless successor has appeared. That makes Goodman one of the few brands whose newest mini-split is an R-410A machine in 2026. The copper line set doesn't care which refrigerant flows through it; your gauges, tools, and any added charge do. Check the nameplate, and match everything to R-410A.
How to find your Goodman model's line set size
- Read the model number on the outdoor unit. Current E-Series units read like RXNG12AXVJU — RXNG marks the outdoor unit, the digits are the capacity in thousands of BTU (09, 12, 18), and the matching indoor head is FTXNG##AXVJU. Legacy units follow MS[C/H][capacity]3E15[AX/MC] — MSC is cooling-only, MSH is the heat pump.
- Check the spec sheet's piping table. It lists the exact liquid and suction diameters, the maximum line length, and the factory charge coverage for your unit — the final word before you buy copper.
Common questions
What size line set does a Goodman 12,000 BTU mini-split use?
A Goodman E-Series 12,000 BTU mini-split uses a 1/4" liquid line with a 3/8" suction line, and the 9,000 BTU model uses the same pair. The 18,000 BTU steps up to 1/4" × 1/2". Confirm against your model's installation manual.
Is a Goodman mini-split really a Daikin?
Effectively, yes. Goodman is a Daikin Comfort Technologies brand, and the current E-Series ductless line (2024 and later) is a rebadged Daikin platform — the model numbers RXNG##AXVJU (outdoor) and FTXNG##AXVJU (indoor) follow Daikin's FTX/RX nomenclature. Line set sizes and length limits track the Daikin spec sheets accordingly.
Do Goodman mini-splits use flared or quick-connect line sets?
Goodman E-Series mini-splits use standard field-flared connections, not pre-charged quick-connect. You cut, flare, and torque the copper, then pull a vacuum before opening the service valves — which needs a vacuum pump and typically EPA 608 certification. The outdoor unit ships pre-charged for the first 32-13/16 ft (10 m) of line per the installation manual.
What is the largest Goodman mini-split?
The current single-zone E-Series tops out at 18,000 BTU, which uses a 1/4" × 1/2" line set — there is no 24k E-Series model. The discontinued MS15 series did offer a 24k (22,000 BTU actual) unit, and that one used a 3/8" × 5/8" line set.
What refrigerant do Goodman mini-splits use? Are they R-32 yet?
The Goodman E-Series ductless line still sells with R-410A. Goodman's ducted central equipment has moved to R-32 (the GLXS and GLZS lines), but no R-32 ductless successor has appeared — so a Goodman mini-split bought today is an R-410A system. Match your gauges and any added charge to R-410A.
Do Goodman central air conditioners use the same line sets as Goodman mini-splits?
No. Goodman central ACs and heat pumps (GSX/GLXS) use a 3/8" liquid line with a 3/4", 7/8", or 1-1/8" suction line depending on tonnage, and the connections are brazed (sweat), not flared. Mini-split flared line sets do not apply to a central Goodman condenser.
Line set sizes for other brands: Daikin · Mitsubishi · MRCOOL · Samsung · Della
This page provides general guidance on Goodman mini-split line set sizing based on Goodman's published specification sheets and installation manuals (E-Series RXNG/FTXNG and legacy MS15 MSH/MSC series), with Goodman central AC piping sizes noted for contrast. Exact diameters, length limits, and charge requirements vary by model — always verify against your unit's official installation manual before purchasing or installing.