Quick answer: A copper coil is refrigeration-grade copper tube wound into a roll, so it can be bent and run on site. Pancake coils are soft, flat-wound rolls for installers. LWC (level wound coil) is long, layer-wound tube for factory production lines, and its temper depends on the maker and product. Straight lengths are rigid bars for exposed runs. To choose, match the format to the job, then the size to your line, and check the tube meets ASTM B280, EN 12735-1 or your project spec.
If you install split ACs, cold rooms or condensing units, picking the right copper coil saves time on site and avoids leaks later. This guide compares the three formats and explains sizes, grades and selection.
What Is a Copper Coil Used For?
Copper tube connects the indoor and outdoor units of an AC, and links the compressor, condenser and evaporator in refrigeration. It conducts heat well, bends easily and brazes cleanly. This guide covers tube sold in coils, not finished evaporator or condenser coils.
What Is the Difference Between Pancake, LWC and Straight Length?
| Type | Form | Temper | Best for | Watch out for |
| Pancake coil | Flat disc, often 15 m (50 ft) | Soft | Split AC line sets, field repairs | Kinks if pulled straight |
| LWC | Long, layer-wound coil | Varies by maker and product: soft annealed, light annealed and in some cases hard | Factory bending and production lines | Needs uncoiling equipment |
| Straight length | Rigid fixed bars | Hard drawn under ASTM B280. Under EN 12735-1, hard or half-hard | Risers and exposed commercial runs | More joints and fittings |
State the temper according to the applicable standard and the product. Check it on the product data sheet rather than assuming it from the format.
What Sizes Do Copper Coils Come In?
ACR coils are usually sold by outer diameter in inches: 1/4″ (6.35 mm), 3/8″ (9.52 mm), 1/2″ (12.7 mm), 5/8″ (15.88 mm), 3/4″ (19.05 mm) and 7/8″ (22.2 mm). A small split AC typically uses a thin tube for the liquid line and a larger one for the gas line. Always follow the unit’s manual. Check wall thickness too, since R410A and R32 run at higher pressure than older refrigerants.
Which Copper Grade and Temper Should You Use?
ASTM B280 covers seamless copper tube for air conditioning and refrigeration field service, in coppers C10200, C12000 and C12200. C12200 is the most common choice. EN 12735-1:2020 covers refrigeration and air-conditioning piping tube in Europe. It is the comparable European ACR tube standard, but it is not an exact one-to-one equivalent of ASTM B280, because dimensions, material conditions and requirements differ.
Under B280, soft coils are dehydrated and closed at both ends. Hard-drawn straight lengths are cleaned and closed at both ends. Look for capped ends when you buy.
How Do You Choose the Right Copper Coil?
Step 1: Pick the format. Pancake for site work, LWC for production, straight length for rigid exposed runs.
Step 2: Match the diameter. Use the unit’s connection sizes and the manufacturer’s line table.
Step 3: Check wall thickness. Confirm it suits your refrigerant’s pressure.
Step 4: Check the standard and temper. Look for ASTM B280 or EN 12735-1:2020, which are not exact equivalents, and for sealed ends. Confirm the temper on the product data sheet.
Step 5: Work out the quantity. Measure the actual routed pipe length, including bends and vertical runs. Add only the allowance your project or site needs for routing, service loops and installation waste. Also check the equipment manufacturer’s maximum line length.
Worked example: An AC run measures 8 m along its actual route, including bends and vertical sections, so it needs 8 m of liquid tube and 8 m of gas tube. If the project allows, for example, 10% for service loops and waste, that gives 8.8 m of each size, so one 15 m coil of each size covers it. Confirm that the total stays within the manufacturer’s maximum line length.
Why Does UAE Climate Change Copper Coil Selection?
- Heat: Outdoor runs get very hot. Insulate the suction or gas line, and any other line the equipment manufacturer or system design requires. Outdoor insulation should suit the operating temperature and be protected from UV and weather exposure.
- Dust and sand: Keep the ends capped until you make the joint.
- Coastal air: Salt and moisture attack bare copper and fittings. Seal insulation joints near the coast.
What Mistakes Cause Copper Coil Problems?
- Pulling a pancake coil straight instead of unrolling it, which causes kinks.
- Brazing without nitrogen flow, which leaves scale that can block filter driers.
- Leaving ends open on site, which lets in dust and moisture.
Which Copper Coils Does Haste Offer?
Haste supplies copper coils for HVAC/R, including refrigeration tube in multiple sizes from brands such as Mueller and Krystal. Straight lengths sit under Copper Tubes & Lengths. Send us your tube size, quantity and refrigerant, and we will help match the right coil.
Frequently Asked Questions
What is a copper coil used for? It carries refrigerant between parts of AC and refrigeration systems, such as the indoor and outdoor units.
What is the difference between a pancake coil and an LWC? A pancake coil is a short, flat roll for site work. An LWC is a long, layer-wound coil for factory production, and its temper depends on the maker and product.
Should I use soft or hard copper tube? Soft coils suit bending on site. Straight lengths, usually supplied in a harder temper, suit rigid, exposed runs. Check the temper for the standard and product you are buying.
What does ASTM B280 mean? It is the standard for seamless copper tube used in air conditioning and refrigeration field service.
Summary
- A copper coil is copper tube wound into a roll for AC and refrigeration lines.
- Pancake suits site work, LWC suits factories, and straight lengths suit rigid runs. Check the temper for each product.
- Match the size to the unit, and check wall thickness for your refrigerant.
- Look for ASTM B280 or EN 12735-1:2020, which are not exact equivalents, and for sealed ends.
- Measure the real routed length and add only the allowance you need.
- UAE heat, dust and coastal air call for suitable insulation and capped ends.
Haste Trading has supplied HVAC/R products in the UAE since 1983. If you are unsure which coil fits, get in touch with our team.
This guide draws on general refrigeration practice and ASTM B280. Always confirm requirements against the unit manual and project specification.