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

Plumbing; copper pipesImage by 5317367 (Pixabay)

In this article, we will compare copper vs. PEX plumbing to find the best type for home water heating.

Copper and PEX are two of the most popular plumbing types for residential and commercial use. They both have great benefits that can be used in new installations, for repairs, upgrades, and renovations, but also come with disadvantages. 

Let's see how they compare.

Copper vs. PEX – What's the difference

Copper

Copper is the oldest metal used by man. It is time-tested material, and many professionals are familiar when using it. It is tough and ductile, easy to form, machine, and cut, making them a favorite material.

Copper is used in various industries, including building, electronics, transportation, machinery, etc. The reasons for its popularity are that copper and copper alloys have excellent heat and electrical conductivity, corrosion resistance, and can also last very long.

Copper is primarily used in building industries such as residential homes. Plumbing and water heating systems use copper piping connected mostly with high heat and solder and push-to-connect fittings.

Copper can last longer than PEX. A typical lifespan for copper is from 50 to 70 years, while PEX can last 30 to 50 years.

PEX

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

This is a relatively new material, invented and used since 1970. It can often be seen in radiant floor heating, installed under floors, or driveways.

There are three main types of PEX piping: PEX-A, PEX-B, and PEX-C, where PEX-A is the most flexible and kink resistive of all three. 

As opposed to copper, PEX is resistant to scale, corrosion, freeze breakage, and chlorine. It doesn't degrade like copper or develop pinholes, so there is less chance for 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. It doesn't need as many fittings as copper. Buy it online and get fast delivery and savings.

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PEX piping advantages

  • Cheaper than copper. PEX pipes are cheaper than copper. According to angi.com, experts in-home repairs, PEX pipes cost 50 cents to $2 per linear square foot, while copper costs $2 to $4. Installation is 20-40% cheaper than copper, on average.
  • Lower environmental impact. PEX pipes are made of polyethylene, a by-product of oil and natural gas. Since oil and gas are already being extracted for energy use, PEX can be made without any additional impact on the environment. According to Purdue University, PEX pipes can leach chemicals into the water passing through, also causing odors.
  • Lower energy waste. Since PEX has better insulation properties than copper, there will be less energy waste when water travels from a water heater to the tap or appliance.
  • Resistant to sediment buildup. Due to the material used and smooth pipe interior, PEX pipes are resistant to mineral deposits and scale.
  • Reduced noise. Since PEX pipes are flexible, soft, and can absorb sudden pressure changes, they are not as susceptible to noise transmission and water hammer as copper.
  • It doesn't corrode and burst. PEX doesn't corrode or deteriorate. This makes it favorite material to use for potable water. Also, it is more resistant to bursting during freezing temperatures than metal.
  • Control and savings. PEX uses manifolds to better manage hot and cold water feed, reduce the pipe size, decrease the number of fittings, and increase efficiency.
  • Easy installation. Plastic and flexible PEX pipes you can easily 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 it behind the wall, into the slab, under the flooring, and in tight spaces. 
  • Many applications. Except for plumbing and radiant floor heating, PEX can be used for ice and snow melting or warming up the turf.
  • Long-lasting. A long lifespan makes customers happy and less polluted environment as there is less waste.

PEX piping disadvantages

  • PEX might require some planning and design, professional installation, and special equipment.
  • PEX must be installed in approved locations and away from heat, flame, and potential damages.
  • It can get damaged when exposed to UV light.
  • It can leach toxic chemicals.
  • It is semi-permeable, so the water inside the pipes can be contaminated from the outside.
  • PEX fittings cost much more than copper.
  • PEX can be damaged by pests and chemicals.
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Copper piping advantages

  • Long lifespan. According to some experts, copper piping can last 50 to 70 years.
  • Recyclable. Used copper can easily be remelted and reused.
  • Many applications. Since copper 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, copper is easy to work with, form, machine, fabricate, join, and cut.
  • Corrosion resistance. Copper 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, copper 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.

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 copper 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. Copper 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. Soldering copper often requires some expertise.
  • Higher prices. Copper costs more than PEX.
  • Metallic flavor. Many complains about the metallic taste in their drinking water.

Connecting PEX to copper?

Connecting PEX to copper is easy. SharkBite fittings make PEX to copper transition easy and fast. This is especially important during repairs and emergencies.

Whether pipes are behind the drywall, under the flooring, or in tight spaces, these push-to-connect connections are easy to make without using any special tools or soldering.

SharkBite vs. solder – Which one is better?

For many professionals soldering copper 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 copper 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.

Copper vs. PEX – Which one to install?

As we can see from our copper vs. PEX comparison, PEX plumbing is one of the most cost-effective options out there that deliver superior performance over copper. Pipes are flexible, easy to handle, and install, making them more DIY-friendly. Also, they are cheaper by over 50% than copper. And that is the reason why many newer homes today are fitted with PEX pipes.

On the other side, copper is rigid, durable, and long-lasting, that's been in the industry for many years. It requires more than basic knowledge for the installation, but it needs more connections and labor hours. While it's been the main piping type in older homes, it still plays an important role in plumbing and water heating for new constructions.

Selecting copper or PEX piping depends on your project, budget, feasibility, and other factors. And that is why it is sometimes hard to decide.

Talk to your local HVAC or plumbing expert to get more information or have the piping installed in your house professionally.

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