Leading the way with copper pipes


20 July 2022

Andrew Surtees of the Copper Sustainability Partnership (CuSP) explains why copper is the sustainable choice for air conditioning installations.

With heatwaves pushing up the demand for air conditioning in the UK, we are also seeing an increased demand for copper pipes. And it’s easy to see why installers love copper so much – it is a trusted, reliable, and infinitely recyclable material. 

One of the main reasons for why copper is the material of choice for air conditioning systems is because it is a superior conductor of heat, so can withstand large variations in temperature without expansion or contraction issues. 

An air conditioner requires high efficiency heat transfer in order to be as energy efficient as possible and reduce power consumption, so the pipes must be made of materials with a high thermal conductivity – making copper the perfect match.

Another reason why copper works best with air conditioning is its ability to be bent and brazed, which is good because the installation of air conditioners often requires sharp bending of pipes. Not only this, but copper can also be jointed using press fittings, which speeds up installation times. 

Anti-corrosion properties

Corrosion also needs to be considered when choosing which pipes to install an air conditioner with. Copper does not react with other chemicals, meaning that it is excellent at resisting corrosion. The pipes inside an air conditioner are constantly in contact with refrigerants at different temperatures, as well as water, depending on the installation. With its anti-corrosion properties, using copper will ensure that the pipes don’t suffer from cracks and leakages, offering a longer lifespan compared to using other types of pipes. 

In recent years, manufacturers have introduced hybrid VRF systems, using water as the cooling and heating agent. Also used in heat pumps, these systems can be used with plastic pipes, but construction professionals and installers have continued to use copper and are right to question the suitability of plastic. 

Plastic pipes are not good thermal conductors and are much thinner and weaker than copper, so are unable to withstand a wide range of temperatures and pressures without cracking – making them the wrong choice for air conditioning units and heat pumps.

What’s more, heat pumps have the ability to be used as a source of cooling, as well as heat, so are an alternative to air conditioning units. With this in mind, and with the popularity of heat pumps rising, there is an increasing requirement for professional installers who use reliable, sustainable materials like copper.

Copper is an infinitely recyclable material, with a fully developed scrap-collecting infrastructure in place

Putting the planet first

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If air conditioning is to become the norm in UK commercial and residential spaces, we must continue to use environmentally friendly materials to accompany them. Some air conditioner manufacturers have started to suggest that installers can use multilayer plastic pipe alongside their systems, as an alternative to copper, but installers should not be tempted to do this – it would only be a backward step when we already have a practical, sustainable material in copper. 

Multilayer plastic pipe typically consists of three layers: an outer plastic layer which is usually made of polyethylene, which encases a central aluminium layer which in turn encases a final plastic layer, usually made from a similar material to the outer layer. 

Due to the addition of aluminium tube in its composition and the complexity of its make-up, multilayer plastic pipe is virtually impossible to recycle as it’s very difficult to separate the metal from the plastic. According to the University of Wisconsin-Madison, around 100 million tonnes of multilayer thermoplastics are produced globally each year and, because there is no way to separate the polymers, almost all of that plastic ends up in landfills or incinerators. 

Many claim that multilayer plastic pipes are recyclable but, as it stands, there are no recycling frameworks in place, so its recyclability is theoretical. This is simply an example of greenwashing; focusing on the benefits of plastic and greatly exaggerating its recyclability. 

Copper, on the other hand, is an infinitely recyclable material. It has been recycled and re-used for as long as the material itself has been in use and there is a fully developed scrap-collecting infrastructure which has existed for centuries. 

No loss in performance

When copper pipes come to the end of their life, they are taken to a scrap merchant and, unlike multilayer plastic pipes, are 100% recycled. They simply go into the furnace and are melted down to form a billet of copper, which is stretched out, cut to size, and made into brand new pipes. 

What’s more, this recycling process doesn’t cause any loss in performance or properties of the new pipes. Copper used once will be identical to that used 1,000 or 1,000,000 times so you should never see scrap copper on a skip. 

As a result of this effective recycling process, around half of Europe’s copper demand is currently being met by recycled materials and, to date, at least 65% of all copper mined remains in circulation, available for use. As recycling techniques improve, this figure will only increase and the need to mine will continue to decline – which is good, because the recycling of copper uses 85% less energy than mining raw material. 

So, for any construction professionals who are beginning to see an increase in air conditioning installs, we urge you to continue using copper, the traditional, professional choice. Why make the switch to an environmentally damaging, unreliable product like multilayer plastic pipe when copper is readily available and offers a much more sustainable, energy efficient and reliable solution? 

Continue to make the professional, sustainable choice. Continue to choose copper. 

  • CuSP is a UK-wide organisation working to unify the construction and plumbing industries around the need to achieve greater environmental thinking, insight sharing, and collaboration - using copper as a driving force for a more sustainable future. To find out more about the benefits of copper pipes, click here.