BOTANVÈCopper Pipe Size Guide for AC Installation
Every split AC uses two copper lines: a small liquid line and a larger suction line. The sizes are fixed by the manufacturer for each capacity, but installers still need to know the typical sizes to quote a job, buy the right coils and check that a long run will not starve the unit. This guide gives the common sizes for units sold in the UAE.
Typical connection sizes
| Capacity | Liquid line | Suction line | Coils to buy (≤14 m run) |
|---|---|---|---|
| 1 ton (12,000 BTU/h) | 1/4" | 3/8" | 1 × 1/4", 1 × 3/8" |
| 1.5 ton (18,000) | 1/4" | 1/2" | 1 × 1/4", 1 × 1/2" |
| 2 ton (24,000) | 1/4" | 5/8" | 1 × 1/4", 1 × 5/8" |
| 2.5–3 ton (30–36,000) | 3/8" | 5/8" | 1 × 3/8", 1 × 5/8" |
| 4–5 ton (48–60,000) | 3/8" | 3/4" | 1 × 3/8", 1 × 3/4" |
Insulating copper pipes in UAE conditions
In the UAE climate, both the suction line and the liquid line must be insulated — not just the suction line as sometimes practised in temperate climates. Outdoor ambient temperatures above 40°C will cause significant heat gain on an uninsulated liquid line, increasing subcooling losses and reducing system capacity. Use closed-cell elastomeric foam insulation (Aerofoam or equivalent) with a minimum wall thickness of 13 mm on the suction line and 9 mm on the liquid line. Secure insulation seams with adhesive and protect outdoor sections with UV-resistant tape or aluminium cladding.
Flaring copper for R410A
R410A operates at approximately 1.6 times the pressure of R22. Standard R22 flare dimensions are not suitable for R410A connections — use an R410A-rated flaring tool that produces the correct flare angle and diameter. Over-flaring or under-flaring causes leaks at the connection. Always deburr the pipe end before flaring, and apply a small amount of refrigeration oil to the flare face before tightening the flare nut.
Always confirm against the outdoor unit nameplate — some brands differ by one size. The copper pipe size helper applies these rules and calculates coil quantities for your run.
Wall thickness and R410A
R410A operates at roughly 1.6 times R22 pressure. Use refrigeration-grade (ACR) copper — Type L or the manufacturer-specified wall thickness (commonly 0.8 mm for 1/4"–1/2", 0.8–1.0 mm for 5/8"–3/4"). Flare with an R410A-rated eccentric flaring tool and use the flare nuts supplied with the unit or R410A-rated replacements.
Maximum run and rise
Most residential splits allow 15–25 m total pipe length and 10–15 m height difference without modification; beyond that, additional refrigerant (typically 15–30 g per metre) and sometimes a larger suction line are required. Long vertical risers may need oil traps every 6–8 m so compressor oil returns. Check the installation manual for the specific model.
Insulation and routing
In the UAE both lines should be insulated with closed-cell elastomeric insulation (typically 9–13 mm wall) to prevent condensation and capacity loss in 45 °C ambient. Keep bends gentle (use a bender, not by hand), avoid kinks, and route lines so that condensate drains do not run uphill.
Where to buy
Maksal and Mueller coils in all common sizes ship next business day UAE-wide; compare in the copper price guide.
Frequently asked questions
What size copper pipe for 1.5 ton AC?
Usually 1/4" liquid and 1/2" suction.
What size copper pipe for 2 ton AC?
Usually 1/4" liquid and 5/8" suction.
Can I use plumbing copper for AC?
No — use ACR-grade refrigeration copper, which is cleaned, capped and rated for refrigerant pressures.
How long can the pipe run be?
Typically 15–25 m for residential units before additional refrigerant or upsizing is needed; check the manual.
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This guide is general information based on BOTANVÈ catalogue data and widely published HVAC-R practice. It is not a substitute for the equipment manufacturer's installation manual or the advice of a qualified engineer. Prices and availability change; the product page is authoritative.