Blueridge line set sizes
The right line set diameter for your Blueridge mini-split by capacity — plus the length limits and the one spec worth checking first: Blueridge's vertical lift tops out lower than most. Prefer to size by run length too? Use the size calculator.
Blueridge line set size by capacity
Line set diameter is set by your system's capacity. Match your Blueridge unit's BTU rating to the liquid-and-suction pair below — these reflect the BMKH single-zone series sold by Alpine Home Air.
| Blueridge system 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" |
| 24,000 BTU | 1/4" × 5/8" |
| 36,000 BTU | 1/4" × 5/8" |
Like a few other OEM-built brands, Blueridge keeps a 1/4" liquid line even on its 24k and 36k units, pairing it with a larger 5/8" suction line. Note that the newer S1 series differs at 24k, so verify your series. Blueridge is sold by Alpine Home Air and built by Midea, so the BMKH installation manual for your exact model is the authority — confirm the sizes there before buying.
A real field install — and a lower lift limit
Blueridge BMKH and S1 systems are standard field-flared units: you flare the copper, then pull a deep vacuum (to about 500 microns) before opening the service valves, which needs a vacuum pump and manifold gauges. Blueridge does sell a separate DIY model (such as the BMY12DIY) with a factory pre-charged line set, but that is a distinct product. One spec to watch: Blueridge allows only about 33 ft of vertical separation between units across all sizes — lower than Mitsubishi or Daikin — so plan tall installs around that limit.
Refrigerant and install
Blueridge BMKH and S1 single-zone systems run R-410A; no R-32 or R-454B single-zone variants were found at the time of writing. The copper line set is the same regardless, but your vacuum pump, gauges, and any field charge must match your unit's refrigerant. Shop standard line sets for a Blueridge install, or see pre-charged line sets if you want the no-vacuum route on a compatible system.
Blueridge line set length limits
Diameter is only half the spec. Your Blueridge system also limits how long the line set can run and how far the indoor and outdoor units can sit apart in height. Plan your run to the figures below, then confirm the exact limits for your model in its installation manual.
| Minimum line length | Maximum line length | Max vertical separation | Pre-charged for |
|---|---|---|---|
| 10 ft (3 m) | 50–100 ft by capacity | 33 ft (all sizes) | 25 ft |
Blueridge BMKH units allow about 50 ft of line on 9,000–12,000 BTU models, about 82 ft at 18,000–24,000 BTU, and about 100 ft at 30,000–36,000 BTU. The vertical separation limit is about 33 ft across all sizes — notably lower than many competitors, so a tall install needs planning. The factory charge covers about the first 25 ft; beyond that an HVAC pro adds about 0.2 oz per foot on smaller units and 0.5 oz per foot on the 30k–36k. Blueridge sets a minimum of about 10 ft.
How to find your Blueridge model's line set size
- Identify the series and capacity. Note the model number — most single-zone units are the BMKH series, while the newer S1 (BMX/BMY) series can differ at 24k.
- Check the installation manual. It lists the exact liquid and suction diameters, the maximum line length, the vertical lift, the pre-charge distance, and the refrigerant for your model — the final word.
Common questions
What size line set does a Blueridge 12,000 BTU use?
A Blueridge BMKH 12,000 BTU uses a 1/4" liquid line with a 3/8" suction line, the same pair as the 9,000 BTU. Larger units step the suction up while keeping the 1/4" liquid line. Confirm against your model's installation manual.
Does Blueridge use a DIY pre-charged line set?
Most Blueridge systems (BMKH and S1) are standard field-flared units that need a vacuum pump. Blueridge does sell a separate DIY model, such as the BMY12DIY, with a factory pre-charged line set, but that is a distinct product — check your model before assuming.
What is the minimum line set length for a Blueridge mini-split?
Blueridge specifies a minimum line set length of about 10 feet (3 m) to limit noise and vibration. Keep your run at or above that and confirm the figure in your model's manual.
What is the maximum line set length for a Blueridge mini-split?
Blueridge BMKH units allow about 50 ft on 9,000–12,000 BTU models, about 82 ft at 18k–24k, and about 100 ft at 30k–36k, with up to 33 ft of vertical separation, which is lower than many competitors. The factory charge covers about the first 25 ft; beyond that an HVAC pro adds refrigerant. Confirm your unit's maximum in its manual.
This page provides general guidance on Blueridge mini-split line set sizing based on published Blueridge and Alpine Home Air specifications. Exact line diameters vary by series and model, and lengths, maximum line length, vertical lift, and refrigerant differ by unit — always verify against your unit's official installation manual before purchasing or installing.