Air conditioning tubing installation

Whether you are installing a new "split" system or replacing old, inefficient pipework, the quality of the tubing installation dictates the lifespan of your equipment. Poorly installed lines lead to refrigerant leaks, which are expensive to fix and damaging to the environment.

What Does the Work Involve?

• Site Survey: Mapping the most efficient route for refrigerant lines, condensate drains, and power cables to minimise impact on your home's aesthetics.
• Core Drilling: Using specialist diamond-tipped drills to create clean penetrations through external brickwork or stone for the pipework to pass through.
• Pipe Preparation: Measuring, cutting, and deburring high-grade copper tubing before flaring the ends or brazing joints to create hermetic seals.
• Insulation: Fitting closed-cell thermal insulation to every centimetre of the copper line to prevent energy loss and stop condensation from dripping inside your walls.
• Containment: Securing the lines within UV-resistant plastic trunking (conduit) on external walls to protect the pipes from the British weather and accidental damage.
• Testing: Performing a dry nitrogen pressure test to check for leaks, followed by a vacuum pump-down to remove all moisture and air from the system.
• Commissioning: Releasing the refrigerant charge and checking the "sub-cooling" and "super-heat" temperatures to ensure the system is running at peak efficiency.

Typical Costs

The cost of tubing installation is usually bundled into a full AC install, but for repairs or complex retrofits, the following rates apply. All prices include VAT at 20%.

Several factors influence the final price, including the total length of the run, whether the pipes are hidden inside walls (chasing), and the type of refrigerant required for the system.

How Long Does It Take?

• Standard "Back-to-Back" Install: 2–4 hours. This is where the indoor unit is mounted directly opposite the outdoor unit on the same wall.
• Multi-Room Run: 1–2 days. Complexity increases when pipes must travel through lofts, under floorboards, or across multiple rooms.
• Commercial or High-Rise: 3+ days. Often requires specialist access equipment and longer testing phases.

DIY or Professional?

This is a strictly professional-only task. In the UK, it is a legal requirement under the F-Gas Regulations for anyone working on refrigerant lines to be F-Gas certified. Handling refrigerant without a licence can result in heavy fines and will void your equipment warranty immediately.

Warning: Never attempt to cut or disconnect AC tubing yourself. Refrigerant can cause cryogenic burns to skin and eyes, and releasing it into the atmosphere is illegal.

Choosing the Right Tradesperson

• Check the F-Gas Register: Ensure the individual and the company are registered with REFCOM or Quidos.
• Insurance: Verify they hold valid Public Liability Insurance (minimum £2 million) and specific cover for "hot works" if they are brazing joints.
• Experience: Ask if they have experience with your specific brand of AC (e.g., Daikin, Mitsubishi Electric).

Questions to ask:

• "Are you F-Gas Category 1 certified?"
• "Will you provide a commissioning report and a leak test certificate once finished?"
• "Does the quote include the cost of external trunking and weatherproofing the wall entry points?"
• "How do you handle condensate drainage—gravity fed or with a pump?"

UK Regulations

• F-Gas Regulations (EU 517/2014): Retained in UK law, this dictates who can handle refrigerants and how leaks must be recorded.
• Part P (Electrical Safety): Most AC installs require a new dedicated circuit; this must be signed off by a competent electrician.
• Building Regulations (Part L): Covers the conservation of fuel and power, requiring specific insulation thickness on all pipework.
• Planning Permission: Generally not needed for domestic units under "Permitted Development," but check if you live in a Conservation Area or a Listed Building.

Common Problems

• Kinked Pipes: If copper is bent too tightly without a pipe bender, it restricts refrigerant flow, causing the compressor to burn out.
• Poor Insulation: Gaps in insulation lead to "sweating," where condensation ruins your internal plasterwork or ceiling.
• Inadequate Vacuuming: Failing to remove moisture from the lines creates acid inside the system, which eats the compressor from the inside out.
• Leaking Flares: Poorly made connections are the number one cause of gas loss; they must be tightened to specific torque settings.

Frequently Asked Questions

Can the tubing be hidden inside my walls?

Yes, this is called "chasing." The engineer cuts a groove into the masonry, installs the pipes, and then plasters over them. This is best done during a renovation, as it creates significant dust and requires redecoration.

Why is my AC pipe dripping water outside?

This is usually the condensate drain, which is separate from the copper refrigerant lines. It is perfectly normal as the system removes humidity from your room. However, if the copper pipes themselves are dripping, the insulation has likely failed.

How long does air conditioning tubing last?

High-quality copper tubing can last 15–25 years. However, the rubber insulation often degrades faster if exposed to direct sunlight, so it should be protected by trunking.

Do I need to replace the pipes if I get a new AC unit?

Not always. If the old pipes are the correct size and pressure-rated for the new refrigerant (e.g., R32), they can often be flushed with nitrogen and reused. Your engineer will advise after a pressure test.

What is "trunking" and do I have to have it?

Trunking is the plastic casing that covers pipes on your external walls. While not strictly mandatory, it protects the insulation from birds and UV damage, and makes the installation look much neater.