Page Contents
Quick Answer
Yes, there is typically copper inside a water heater. The most common place to find copper is in the heat exchanger coils that heat the water. These coils allow water to flow through while the heat source, either gas or electric, heats the coils to in turn heat the water. Copper is an excellent conductor of heat which makes it well-suited for this application.
Copper Heat Exchanger Coils
The copper coils inside a water heater are part of the heat exchanger system. As hot gases or heating elements pass over the coils, the copper efficiently conducts the heat into the water running through the pipes. This rapidly heats the water to the set temperature before sending it into the storage tank portion of the heater.
Copper is used for a few key reasons:
- Excellent heat conduction – Copper transfers heat better than most metals, making it very effective at heating the water.
- Resists corrosion – Copper holds up well against corrosion from water over time.
- Easy to work with – Copper tubing is readily available and simple to install in coils.
- Safe for potable water – Copper does not contaminate drinking water like some metals can.
The amount of copper used can vary based on the size and style of the water heater. But in general, heat exchanger coils account for most of the copper found in a unit.
Other Copper Components
While copper coils make up the majority, there are a few other places copper may be found in a water heater:
– Connective piping – Short lengths of copper piping may connect to the inlet and outlet of the coils. This allows for easy attachment of water lines.
– Fittings – Elbows, tees and other fittings are often made of copper for sealing to the coils and piping.
– Cold water inlet – Particularly on older units, the cold water inlet line feeding into the tank may be copper. Newer units tend to use flexible water supply lines instead.
– Heat traps – Special u-shaped copper tubing may be found on the hot and cold water lines to prevent heat loss through convection.
– Anodes – Some high-end units use copper alloy anode rods to protect the inner tank from corrosion. Standard anodes are typically magnesium or aluminum.
So in total, a water heater may contain several feet of copper tubing and components, ranging from a few pounds up to 10-15 lbs on larger units. While not a huge amount, it does add up with the number of water heaters in use.
Types of Water Heaters
The use of copper is standard across different types of water heaters:
Conventional Storage Tank Water Heaters
This is the most widely used type of residential water heater in the US. It consists of an insulated tank that holds heated water along with some type of fuel source to heat it, either gas or electric. The copper components are generally consistent on these units.
Tankless/On-Demand Water Heaters
Tankless heaters rapidly heat water as it flows through the unit, eliminating the storage tank. But they still rely on copper heat exchanger coils to transfer the heat. Tankless may use more copper since they have higher heating demands.
Heat Pump Water Heaters
Heat pump units pull ambient heat from the air to heat the water. But they still require copper coils to transfer that heat efficiently to the water flow. The only exception would be air-sourced direct heat pump water heaters that lack a storage tank and heat water directly as it flows through.
Solar Water Heaters
Systems with solar thermal collectors use copper coils in the collectors and also as a backup heat exchanger. This allows the units to retain the high heat transfer properties of copper.
So in summary, copper plays an important role in the vast majority of residential and commercial water heating systems. It enables heating the high volumes of water needed in an efficient and durable manner.
Role of Copper in Water Heaters
To understand why copper is so prevalent in water heaters, it helps to look at the key reasons it is used:
Heat Transfer
Copper has among the highest thermal conductivity ratings of commonly available metals. This allows copper coils to rapidly extract heat from combustion gases or heating elements and transfer it to the water. This makes the heating process highly efficient.
Corrosion Resistance
Although not as corrosion resistant as stainless steel, copper holds up very well over the life span of a water heater. This allows manufacturers to use economical copper coils without sacrifice to longevity.
Availability
Copper tubing has been mass produced and widely used for decades in plumbing applications. This makes it inexpensive and readily available in a range of sizes. Manufacturers can easily obtain quality copper coils for production.
Malleability
Copper tubing can be bent, expanded and joined easily compared to materials like steel. This allows it to be formed smoothly into the tight heat exchanger coils within a water heater.
Code Approval
Building and plumbing codes permit the use of copper for potable hot water systems. So manufacturers can utilize copper broadly without any regulatory restrictions.
Cost Effectiveness
With all of its performance, availability and working properties, copper hits a sweet spot of being affordable compared to other metals. This makes it a cost-effective solution.
So in summary, copper has proven itself to be uniquely well-suited for use in water heating systems compared to alternatives on the market.
Copper Coil Designs
There are a few common copper coil designs used inside water heaters:
Helical Coils
This is where copper tubing is wrapped around in a spring-like helix shape with tight loops. It maximizes surface area for heat transfer. Helical designs are used in tank-style electric water heaters.
U-Shaped Loops
Short u-shaped lengths of straight copper tubing are connected in a series to form the heat exchanger in some models. This style is simpler to manufacture.
Straight Coils
Some tankless and on-demand models use more linearly arranged copper coils consisting of straight tubing runs connected by bend sections. This enables high water flow rates.
Flame Cradles
In gas water heaters, you may see a U-shaped copper coil called a flame cradle that cradles the gas burner. This pre-heats incoming cold water using residual heat.
So manufacturers utilize a variety of efficient copper coil arrangements tailored to the type of water heater.
How Copper Coils Are Installed
The copper coils must be securely installed within the water heater to maximize performance. Here is an overview of how they are mounted:
Coil Supports
Brackets are attached inside the tank to hold the coil in the proper orientation and prevent movement. These keep the coils stable and supported.
Coil Spacing
Coils are carefully arranged to optimize spacing in relation to the heat source, tank walls and water connections. Proper spacing maintains efficiency.
Water Connections
Inlet and outlet pipes are secured to the coils using soldering or high-temperature resistant gaskets. This seals the system from leaks.
Heat Source Interface
Where applicable, coils are positioned against the combustion chamber walls or heating elements to use the heat source efficiently.
Insulation
Once mounted, coil assemblies are enclosed using insulation to minimize standby heat loss. This increases efficiency.
With good design, copper coils can operate for decades within a water heating system. Proper installation is key to their longevity.
Maintaining Copper Water Heater Coils
While copper coils are durable, there are a few maintenance items to ensure their optimal performance:
Water Chemistry
Maintain water pH between 6.5-8.5 and minimize corrosive elements to prevent copper corrosion over time.
Sediment Removal
Drain tanks periodically to flush sediment that could build up on coils and reduce heat transfer.
Leak Checks
Inspect coils and connections for leaks annually as part of water heater maintenance. Repair any issues immediately.
Scale Removal
Check coils for limescale buildup which reduces efficiency. Remove any accumulations found.
Anode Replacement
For units with copper/aluminum anodes, replace these every 2-4 years as needed to maintain corrosion protection.
With regular maintenance and care, the copper components can provide decades of reliable service life in a water heating system.
Conclusion
In conclusion, the use of copper within residential and commercial water heaters is very prevalent, especially in the form of heat exchanger coils. Copper offers an ideal balance of performance, cost-effectiveness and durability that makes it well-suited for this vital component. While not the only metal found in a water heater, copper certainly accounts for the majority and enables efficient hot water production through its beneficial properties. With proper installation and maintenance, copper coils and piping will provide decades of reliable operation. So if you have a water heater, you’re almost guaranteed to have copper inside!
| Location | Copper Components |
|---|---|
| Heat Exchanger | Coils, fittings, piping |
| Water Lines | Inlet/outlet piping, connectors |
| Other | Anodes, couplings, valves |
Key Benefits of Using Copper
- Excellent heat conduction
- Corrosion resistance
- Easy installation
- Readily available
- Cost effective
- Safe for potable water systems