ACR Copper Tube & Line Sets

ACR copper tubing and line sets carry refrigerant between the outdoor and indoor sections of air conditioners, heat pumps, and ductless mini splits, and between condensing units and evaporators in commercial refrigeration. This category covers HVAC copper tubing in soft coils and hard-drawn straight lengths, pre-insulated line sets for split systems and mini splits, and the covers and fittings that finish an exterior run.

Unlike plumbing tubes, ACR tubes are produced and packaged for refrigerant service. It is cleaned, dried, and sealed at the mill so the circuit stays free of moisture and debris. Products are grouped by format so the tube or set matches the job: bare tubing for custom routing, line sets for standard runs, and accessories for exterior protection.

Compare the groups below, then confirm line sizes against the equipment manufacturer's installation instructions before ordering.

ACR Copper Tube & Line Set Products

Soft ACR Copper Coils

Soft annealed copper tubing for refrigeration bends by hand or with a lever bender, so one continuous length can route through walls, attics, and crawlspaces with fewer brazed joints. Coils are typically sold in 50 ft lengths and ship plugged at both ends. They are made from C12200 copper to ASTM B280, the standard for copper refrigeration tubing in air conditioning and refrigeration field service.

Hard-Drawn ACR Copper Tubing

Hard-drawn straight lengths, typically 20 ft, hold their shape on exposed runs, rack piping, and hanger-supported lines in mechanical rooms. Straight tube commonly ships nitrogen-charged and capped.

Split-System Line Sets

Refrigerant line sets for split systems package a liquid line and a larger suction line, pre-cut and factory-insulated. Most air conditioning line sets insulate only the suction line. Stock lengths typically run 15 to 50 ft, and factory insulation keeps thickness uniform along the run.

Ductless Mini Split Line Sets

Ductless mini split sets insulate both lines and often ship with flare nuts installed, so each indoor head connects without brazing. Every indoor head needs its own set, sized to that head's service valves.

Line Set Covers & Accessories

Line set accessories protect the exterior portion of the run. Rigid PVC covers mount to the siding and shield insulation from sunlight, impact, and pests. Wall entry caps seal the penetration, and elbows and end fittings route the cover into the outdoor unit. Insulation tape and replacement foam repair weathered insulated refrigerant lines without cutting into the copper.

How Refrigerant Piping Works and Where to Use It

How Refrigerant Lines Work

The liquid line carries high-pressure liquid refrigerant from the condenser to the metering device. The suction line returns low-pressure vapor to the compressor, which is why it is larger and insulated. Moisture reacts with refrigerant and POE oil to form acids and sludge, and it can freeze at the metering device. That is why the ACR tube is dehydrated at the mill. Keep factory caps in place until the tube is cut.

Residential Split Systems and Heat Pumps

A line set runs from the outdoor unit to the indoor coil. In humid regions such as the Gulf Coast, any gap in suction line insulation collects condensation that can drip inside walls and attics, so keep insulation continuous and tape every seam.

Light Commercial and Refrigeration Systems

Walk-in coolers, reach-in cases, ice machines, and rooftop units commonly use hard-drawn tubes for long, supported runs, with soft coils for final connections at the equipment.

Key Specifications and Planning Steps

Sizing by Outside Diameter

ACR copper tubing is identified by actual outside diameter. A 3/8" ACR tube measures 3/8" OD, while 3/8" Type L plumbing tube measures 1/2" OD. Order by OD to match service valves, flare nuts, and fittings.

Line Size and Run Length

Liquid and suction line sizes, maximum line length, and allowable vertical lift come from the equipment manufacturer's line set chart. Longer runs can require a larger suction line or added refrigerant charge. Common residential pairings include 3/8" x 3/4" and 3/8" x 7/8". Mini splits commonly use 1/4" x 3/8" or 1/4" x 1/2".

Pressure Rating and Wall Thickness

R-410A and A2L refrigerants such as R-454B and R-32 run at higher pressures than R-22. The tube's rated working pressure, set by OD and wall thickness, must meet or exceed the design pressure on the equipment nameplate. Residential copper tube for air conditioning in small diameters generally clears these pressures with standard ACR walls. Verify larger sizes against the manufacturer's rating chart.

Brazing and Line Set Reuse

Flow low-pressure dry nitrogen through the tube while brazing. Nitrogen displaces oxygen and stops oxide scale from forming on the inner wall, where it would otherwise break loose and clog filter driers, metering devices, and compressor valves. Copper is compatible with A2L refrigerants. Reusing an existing line set on new equipment depends on the manufacturer's instructions. The lines must match required sizes and length limits, pass a pressure test and evacuation, and be flushed where required, particularly after an R-22 system that used mineral oil.

Choosing the Right ACR Copper Tube or Line Set

Start with the equipment's line set chart. Choose a pre-insulated set when a stock length and pairing fit the run, soft coils when the route needs custom bends, and hard-drawn HVAC copper tubing for exposed commercial runs. Finish exterior lines with a cover and wall entry cap.

Frequently Asked Questions

What is the difference between ACR copper tubing and Type L copper for HVAC work?

They differ in sizing and preparation. The ACR tube is named by its true OD and arrives cleaned, dried, and sealed for refrigerant, while Type L is named by nominal size, runs 1/8" larger in OD, and is meant for water. Use ASTM B280 tubes for refrigerant circuits.

My new condenser uses R-454B. Can I reuse the existing copper line set or do I need new tubing?

Possibly. Copper itself handles R-454B, so the decision rests on the new unit's installation instructions. Expect to confirm line sizes and length limits, pressure test and evacuate the lines, and flush them if the manufacturer requires it or the old system ran R-22.

What size line set do I need for a 2.5-ton heat pump with a 40-foot run?

A 3/8" liquid and 3/4" suction pairing is common for 2.5-ton equipment. At 40 ft, some manufacturers adjust the suction size or refrigerant charge, and the heat pump's line set chart gives the required size for that length.

How do I keep oxide scale from forming inside copper refrigerant lines when brazing?

Purge the tube with dry nitrogen at low flow during the braze. With no oxygen inside the tube, copper oxide cannot form on the inner wall, which keeps flakes out of filter driers, metering devices, and the compressor.

What does "dehydrated" mean on copper refrigeration tubing, and why does moisture matter in an AC system?

It means the tube was dried and sealed at the mill so no moisture sits inside. In a sealed refrigerant system, water combines with refrigerant and oil to form acids and sludge, and ice can block the metering device. Keep copper refrigeration tubing capped until it is cut.

What accessories do I need to finish a refrigerant line set installation, like covers, wall sleeves, and insulation tape?

Most exterior runs use four-line set accessories: a rigid cover with elbows and couplings, a wall entry cap or sleeve at the penetration, an end fitting at the outdoor unit, and UV-resistant tape to seal insulation seams. For mini splits, add flare nuts if the air conditioning line sets do not include them.