Comparing Copper vs. PEX Plumbing – Which is Better for Water Heating?

When it comes to plumbing options for home water heating, two of the most popular choices are copper and PEX. While both offer benefits for new installations, repairs, upgrades, and renovations, they also come with their own set of drawbacks.

In this article, we will compare copper vs. PEX plumbing, benefits and connecting possibilities to help you determine the best option for your needs.

Copper vs. PEX: Things to consider

Copper

Copper, the oldest metal used by humans, is a time-tested material that many professionals are familiar with. Its toughness and ductility make it easy to form, machine, and cut, making it a favorite material in various industries, including building, electronics, transportation, and machinery. Copper and its alloys are popular due to their excellent heat and electrical conductivity, corrosion resistance, and durability.

Primarily used in building industries such as residential homes, copper piping is commonly used in plumbing and water heating systems, connected mostly with high heat and solder and push-to-connect fittings.

Copper can last longer than PEX, typically lasting from 50 to 70 years, while PEX can last from 30 to 50 years.

PEX

PEX pipes are made of high-density cross-linked polyethylene and have a plastic-like look and feel. When used in residential homes, they come in two colors: blue for cold water lines and red for hot water.

This relatively new material was invented in 1970 and is commonly used in radiant floor heating, installed under floors or driveways. There are three main types: PEX-A, PEX-B, and PEX-C, with PEX-A being the most flexible and kink-resistant of the three.

Compared to copper, PEX is resistant to scale, corrosion, freeze breakage, and chlorine. It does not degrade or develop pinholes, resulting in fewer leaks. PEX pipes are easy to cut and install using standard plumbing tools such as crimp rings, crimping and de-crimping tools, and pipe cutters. They require fewer fittings than copper.

PEX piping advantages

• Cheaper. PEX pipes are generally cheaper than copper pipes. According to Angi.com, a website that provides expert advice on home repairs, PEX pipes cost between 50 cents and $2 per linear foot, while copper pipes cost between $2 and $4 per linear foot. On average, installation is also 20-40% cheaper.
• Lower environmental impact. PEX pipes are made of polyethylene, which is a byproduct of oil and natural gas extraction. Since oil and gas are already being extracted for energy use, PEX can be made without any additional impact on the environment. However, according to Purdue University, PEX pipes can leach chemicals into the water passing through, which can cause odors.
• Lower energy waste. PEX pipes have better insulation properties, which reduces energy waste when water travels from a water heater to the tap or appliance.
• Resistant to sediment buildup. The material used to make PEX pipes and their smooth interior make them resistant to mineral deposits and scale.
• Reduced noise. PEX pipes are flexible and soft, which allows them to absorb sudden pressure changes and reduces noise transmission and water hammer compared to copper pipes.
• It doesn't corrode and burst. PEX pipes do not corrode or deteriorate, making them a preferred material for potable water. Additionally, they are more resistant to bursting during freezing temperatures than metal pipes.
• Control and savings. PEX pipes use manifolds to better manage hot and cold water feeds, reduce pipe size, decrease the number of fittings, and increase efficiency.
• Easy installation. PEX pipes are plastic and flexible, which makes them easy to cut, run, bend, secure, join, and attach. Using quick-to-connect fittings such as SharkBite makes installation easier and quicker than soldering copper pipes. This is especially important when installing pipes behind walls, into slabs, under flooring, and in tight spaces.
• Many applications. Apart from plumbing and radiant floor heating, PEX pipes can also be used for ice and snow melting or warming up the turf.
• Long-lasting. PEX pipes have a long lifespan, which makes customers happy and reduces environmental pollution as there is less waste.

PEX piping disadvantages

• Planning required. PEX might require some planning and design, professional installation, and special equipment.
• It requires careful installation. It must be installed in approved locations and away from heat, flame, and potential damages.
• Not suitable for outdoor use: They are not recommended for outdoor use, as they can be damaged by prolonged exposure to sunlight (UV light) and other environmental factors.
• It can leach toxic chemicals.
• It is semi-permeable, so the water inside the pipes can be contaminated from the outside.
• Expensive fittings. Fittings cost much more than copper.
• Can be damaged by rodents: These plastic pipes can be damaged by rodents, such as mice and rats, which can chew through the plastic material and cause leaks.
  
• Can be affected by chemicals: The pipes can be affected by certain chemicals found in soil, such as pesticides and fertilizers, which can cause the pipes to degrade over time.

Copper piping advantages

• Long lifespan. According to some experts, copper piping can last 50 to 70 years.
• Recyclable. It can easily be remelted and reused.
• Many applications. Since it is strong and ductile, it can be used in many industries.
• High conductivity. Due to high heat and electrical conduction, copper is often used in electrical and building industries.
• Malleability and ductility. Due to its excellent properties, it is easy to work with, form, machine, fabricate, join, and cut.
• Corrosion resistance. The metal and its alloys are highly resistant to corrosion, even if buried for a long time.
• Higher heat resistance. While both PEX and copper can be used for hot water transport, the latter is often used in areas with high heat, while PEX is not. So even if you use PEX throughout the house for hot water delivery, you should not connect it directly to the water heater where the temperature is the highest, but use a copper pipe.
• Cheap fittings. Fittings used with copper tubes are more affordable than PEX fittings such as SharkBite.
• Recyclable: This is a recyclable material, making it an environmentally friendly option for plumbing installations.

Copper piping disadvantages

• High environmental impact. As opposed to manufacturing PEX, copper mining can greatly affect nature. In addition to that, there is a lot of energy used to make pipes.
  
• Energy waste. Copper is metal, and metals are great heat conductors, so when hot water passes through the pipe, it easily losses energy through the pipe walls.
• Fire hazard. It requires soldering to connect pipes and fittings, creating a potential danger. This is especially true when working with a hot propane torch around wood.
• Difficult to install. Copper piping may require more fittings than other materials, which can add to the cost and complexity of installation. Soldering often requires some expertise.
• Corrosion. Copper is susceptible to corrosion, which can lead to pinhole leaks and a shorter lifespan if not properly treated.
• Higher prices. It costs more than PEX.
• Metallic flavor. Many complains about the metallic taste in their drinking water.

What options do I have when connecting copper pipe to PEX?

There are several ways to connect copper pipe to PEX tubing, including:

1. Sweat fittings: This method involves soldering a copper fitting onto the copper pipe and then using a compatible adapter to connect the PEX tubing to the fitting. The adapter is then crimped or clamped onto the PEX tubing to secure the connection.
2. Compression fittings: This method involves using a compression fitting that has a brass or copper ferrule and a compression nut to connect the PEX tubing to the copper pipe. The ferrule is slid over the PEX tubing, and the compression nut is tightened to compress the ferrule onto the tubing and create a watertight seal.
3. Push-to-connect fittings: Connecting PEX and copper is made easy with specialized push-to-connect fittings like SharkBite, which require no tools or soldering. These fittings consist of two components, one for the copper pipe and another for the PEX tubing, that can be quickly and easily pushed together until they lock into place. SharkBite fittings are especially popular for repairs and emergencies when a quick connection is needed.

When you want to attach PEX to copper it's important to ensure that the fitting and tubing used are compatible with both options, and that the connection is properly supported and secured to prevent any damage or leaks. Additionally, it's recommended to consult with a licensed plumber to ensure that the connection is done safely and meets local building codes.

SharkBite vs. solder – Which one is better?

For many professionals soldering pipes is a better and more reliable option. Connections made when sweating copper pipes can last for a long time, especially when dealing with high fluid pressures.

For the newbies, it takes some time and trials to make good-quality connections. Fittings are fixed to the pipe and cannot be reattached or reused. You will need a heat torch, solder, flux, pipe cutter, and sandpaper to properly solder fittings and pipes. And it can be messy.

If you are a DIY handyman and need a quick and easy pipe repair, you might want to go with SharkBite fittings. They are beginner-friendly, easy to use, quick to put on, and ideal for places that are tight and hard to access. While these fittings can rotate after installation and be reused, they are not as reliable as copper fittings. So, keep in mind that the failure rate for SharkBite push-to-connect fittings is higher.

Which is easier to install, maintain and repair, copper or PEX?

Copper pipes require more advanced skills, experience, and specialized tools for installation, such as a torch and soldering materials. The pipes must be measured, cut, bent, and soldered together, which can be time-consuming and labor-intensive, especially for larger projects.

They are generally more difficult to repair than PEX pipes. If it develops a leak or crack, it may require cutting out the damaged section and soldering in a new piece.

Copper pipes are susceptible to corrosion and mineral buildup, which can cause leaks and other issues. Regular maintenance may involve cleaning and flushing the pipes to remove any buildup.

On the other hand, PEX pipes are easier to install and require fewer tools, making them a more DIY-friendly option. PEX can be installed using quick-to-connect fittings such as SharkBite, which do not require any special tools or soldering. This can significantly reduce the installation time and cost, especially for smaller projects.

PEX is also easier to repair. If it develops a leak or crack, it can often be fixed by cutting out the damaged section and installing a new fitting.

They are generally low maintenance due to their resistance to corrosion and scale buildup. However, it is still recommended to periodically inspect the pipes for any damage or leaks.

Ultimately, the choice between copper vs. PEX will depend on your specific needs and circumstances.

Copper vs. PEX – Which one to install?

In this article, we compared copper vs. PEX plumbing and their benefits, as well as connecting options, to help you determine the best option for your needs.

From our comparison, it's clear that PEX plumbing is one of the most cost-effective options available that delivers superior performance. PEX pipes are flexible, easy to handle and install, making them more DIY-friendly. Additionally, they are over 50% cheaper than copper pipes, which is why many newer homes are fitted with them.

On the other hand, copper pipes are rigid, durable, and have been in the industry for many years. They require more than basic knowledge for installation, but they need fewer connections and less labor hours. While copper has been the main piping type in older homes, it still plays an important role in plumbing and water heating for new constructions.

Ultimately, the choice between copper vs. PEX will depend on factors such as budget, project requirements, and personal preference.

To make an informed decision, it's important to talk to your local HVAC or plumbing expert for more information, or to have the piping installed professionally in your home.