Copper Coils for AC & Refrigeration: A Buyer's Guide

Copper tubing is the backbone of almost every AC and refrigeration installation — carrying refrigerant between the condenser and evaporator, forming service loops, and connecting split units to outdoor condensers. Get the wrong grade, size or wall thickness and you're looking at leaks, pressure failures, or a callback. This guide covers what actually matters when specifying ACR (Air Conditioning & Refrigeration) copper coil.

Soft Annealed Coil vs Hard Drawn Length

ACR copper comes in two tempers. Soft annealed coil is flexible, sold in 50ft or 100ft rolls, and can be bent by hand or with a tube bender to route around obstacles — this is what you want for split AC line sets and most field connection work. Hard drawn straight lengths are rigid, hold their shape under pressure without support, and are used for long fixed runs, risers, and refrigeration racks in commercial and industrial installations where the tubing won't be bent after installation.

Standard Grade vs Economical Grade

Within soft annealed coil, wall thickness is the main variable that separates "standard" and "economical" grades at the same outer diameter (OD). Standard grade (e.g. Maksal's ASTM B280 line) carries a thicker wall for a given size, giving it a higher working pressure rating — the right choice for commercial refrigeration, cold rooms, supermarket display units and any installation using higher-pressure refrigerants. Economical grade uses a thinner wall to reduce material cost and is commonly used for lower-pressure residential split AC connection work where the extra pressure margin isn't needed. Both are C12200 copper (99.9% minimum copper content) — the difference is wall thickness and pressure rating, not purity.

Choosing the Right OD Size

ACR coil is sold by outer diameter in fractional inches, from 1/8" up to 1 5/8" and beyond for larger commercial lines. As a rough guide:

• 1/8"–3/8" — liquid lines on small to mid-size split units and service/gauge connections.
• 3/8"–5/8" — suction lines on residential and light-commercial split systems.
• 3/4"–1 1/8" — larger split and ducted systems, and commercial refrigeration suction lines.
• 1 1/8" and above — commercial and industrial refrigeration racks, chillers and large VRF runs.

Always match the OD to the manufacturer's line-set spec for the specific AC or refrigeration unit you're connecting — undersized tubing restricts refrigerant flow and increases pressure drop; oversized tubing wastes refrigerant charge and increases installation cost.

USA-Manufactured Coil

For technicians who prefer or specify US-origin tubing, Mueller Streamline coils are manufactured in the USA to the same ACR standard sizing (1/8" through 1 5/8"), supplied as 50ft coils with 100ft also available on request.

Handling & Storage Tips

• Keep coil ends capped or taped until installation to prevent moisture and debris from entering the tube — contamination is a leading cause of compressor failure.
• Store coils flat or hung, away from direct ground contact, to avoid kinking and denting the copper.
• Always braze with nitrogen purging through the line to prevent internal oxidation (copper scale) that can clog filter driers and expansion valves downstream.
• Pressure test and evacuate the full line set before charging — this catches leaks at joints before the system is put into service.

Shop Copper Coils at Botanvè

We stock Maksal ACR tubing in both Standard and Economical soft annealed grades, Maksal Hard Drawn Lengths for fixed runs, and Mueller USA-manufactured coils — all available across the full 1/8" to 1 5/8"+ size range with trade pricing for bulk orders.