Many HVAC appliances have a component that is known as a &#;heat exchanger.&#; They come in many forms, but it is the metal that composes your heat exchanger that often makes one of the biggest impacts.
Want more information on stainless steel heat exchanger tube? Feel free to contact us.
What this piece of metal does is transfer heat from one fluid (e.g., hot water in your water heater) to another (e.g., domestic water running to your tap). There is a good amount of choice in the metal you can use for that heat exchanger, ranging from bronze and titanium to brass and carbon steel.
However, copper and stainless steel heat exchangers are the most commonly used because they are less expensive and still highly effective. One of the most common questions we are asked by our customers is some variation of: which is better a copper or stainless steel hot water cylinder, water heater, boiler, or other HVAC appliance?
The main concerns of a homeowner when choosing between copper and stainless steel should be thermal conductivity, durability, and price.
In this guide, we look at the pros and cons of copper and stainless steel heat exchangers.
The thermal conductivity of a heat exchanger determines how quickly it transfers the heat from the heating source to the distribution fluid. In this regard, a heat exchanger with copper is much faster at transferring heat than stainless steel.
Here are the basic thermal conductivity levels, measured in watts per meter pre-Kelvin, of the two different metals[1]:
On average, the thermal conductivity of copper is 20 times that of stainless steel. In practical terms, this means that copper can transfer heat 20 times faster. So, if you need quick heating, copper will work to your advantage.
Why would you need to heat something quickly? That&#;s an important question to ask if you are choosing between, say, a copper vs. stainless steel tankless water heater.
For example, if you own a swimming pool and plan on going swimming on an autumn day, a water heater with a copper heat exchanger can get your pool ready for you much faster. With a stainless steel heat exchanger, you could find yourself waiting up to 72 hours before your pool is heated to 10 degrees Celsius.
Even if you don&#;t need to heat things quickly, the higher thermal conductivity offered by copper also leads to higher efficiency. As a result, using a heat exchanger with copper will lead to lower energy costs. After all, a heater or boiler that has to run for longer to heat your home, pool, or tap water is going to cost you more.
Durability is a big concern for heat exchangers when it comes to appliances like a boiler. This is because condensing boilers (the most popular type right now), release a corrosive condensate that can eat away at the metal in the heat exchanger.
A heat exchanger that cannot stand up to the condensate will quickly corrode, requiring a time-consuming and costly replacement. As a result, you will likely want to choose a heat exchanger that can resist corrosion over the long term.
In this case, the clear winner is stainless steel. Unlike standard steel, stainless steel has a property known as &#;passivation.&#; This refers to its ability to form a layer of oxide on itself in response to contacting air.[2]
This layer of oxide protects stainless steel from corrosion and rust, allowing for a longer lifespan than regular steel. It is essentially perfect to use in any heat exchanger that will be in contact with corrosive elements.
On the other hand, copper is much more vulnerable to corrosion. The condensate turns copper atoms into copper ions, effectively dissolving the metal over time. This is a big problem for two reasons. First, because of the lower lifespan; then, because a corroded copper heat exchanger loses efficiency.
Considering that higher efficiency and thermal conductivity was the advantage for copper, having it reduced balances out the other way.
Copper tends to be cheaper than stainless steel when purchased in the same quantity, and that holds true when used in heat exchangers. While that may tempt you into getting copper for your heat exchanger, remember that it is much less durable. You will have to buy more copper replacements to maintain its efficiency levels. As a result, copper can actually end up being more expensive in the long term.
Generally, you will find that heat exchanger manufacturers will offer copper as the default choice because they&#;re cheaper. These companies are aware of the trade-off between the cost and the lifespan, where the cost is a &#;pay now or pay later&#; issue. You either pay more upfront for a stainless steel heat exchanger that will last longer or pay later to replace the copper one sooner.
For more inconel 625 tubinginformation, please contact us. We will provide professional answers.
The ultimate choice comes down to whether you are thinking long-term or short-term. If you plan on adding value to your home by installing high-quality HVAC equipment, go with the long-term option. (e.g., gas boilers and stainless steel heat exchangers). The long-term option will save you money and reduce the need for HVAC services and replacements.
So it should be obvious that stainless steel, the more costly of the two metals, is better for long-term thinkers. However, should you really need a heat exchanger with the highest conductivity to quickly heat large bodies of water (e.g., a pool) or larger homes, then copper might be the better choice.
Of course, stainless steel can do everything copper can, just at a slower pace and slightly higher price.
Made up your mind and ready to get started? Click here to begin!
Material pricing and availability can fluctuate based on market supply and demand, the quantity required for your exchanger, and the components needed. Copper was a low-cost option a few years ago, but now due to supply, it is more expensive than stainless steel. Conversely, Titanium used to be one of the most expensive alloys but is now more reasonably priced. Typically, the more nickel content in a metal, the higher the price.
Here is the relative ranking for some of the common metal material options by price from highest to lowest:
1. MOST EXPENSIVE: Nickel 200, also known as UNS N, is a commercially pure nickel alloy. It is one of the most widely used nickel alloys due to its excellent mechanical properties and high corrosion resistance. Nickel 200 consists of 99.6% pure nickel, with small amounts of impurities such as iron, copper, and manganese.
2. Alloy 625, also known as Inconel 625, is a nickel-based superalloy known for its excellent strength, corrosion resistance, and high temperature performance. It is composed mainly of nickel, with significant amounts of chromium and molybdenum, along with smaller additions of niobium, iron, and other elements. Alloy 625 is widely used in various industries, including aerospace, chemical processing, oil and gas, and marine applications.
3. Monel 400 is a nickel-copper alloy known for its excellent corrosion resistance in various environments. It is composed of approximately 67% nickel and 30% copper, with small amounts of iron, manganese, carbon, and silicon. Monel 400 is highly resistant to corrosive substances such as acids, alkaline solutions, and saltwater. It is often used in applications where resistance to corrosion, erosion, and high temperatures are essential.
4. Hastelloy C22 is a nickel-chromium-molybdenum alloy known for its exceptional corrosion resistance in a wide range of aggressive environments. Hastelloy C22 is particularly resistant to pitting, crevice corrosion, and stress corrosion cracking. Hastelloy C22 is often chosen for chemical processing and waste treatment.
5. Hastelloy C-276 is a nickel-molybdenum-chromium alloy that is renowned for its corrosion resistance and high-performance properties. While similar to Hastelloy C22, Hastelloy C-276 has lower chromium content, easier weldability, and slightly higher upper temperature limits. Hastelloy C-276 is used in various industries, including chemical processing, pollution control, pulp and paper production, and petrochemical applications.
6. Duplex is a super duplex stainless steel alloy that offers excellent strength, corrosion resistance, and durability. It is part of the duplex stainless steel family, which combines the desirable properties of both austenitic and ferritic stainless steels. Duplex is characterized by its high levels of chromium, molybdenum, and nitrogen, providing superior resistance to corrosion and high mechanical strength.
7. AL6XN is a high-performance austenitic stainless steel alloy that offers exceptional corrosion resistance and mechanical properties. It is specifically designed to withstand highly corrosive environments, including chloride-rich environments, acids, and seawater. AL6XN is known for its versatility, making it suitable for various applications in industries such as chemical processing, pulp and paper, oil and gas, and desalination.
8. Titanium is a lightweight metal known for its high strength, low density, and excellent corrosion resistance. Titanium is widely used in various industries due to its unique combination of properties.
9. Duplex is a stainless steel alloy with a combination of austenitic and ferritic microstructures, known as a duplex structure. It offers excellent strength, corrosion resistance, and durability, making it suitable for a wide range of applications. Duplex is highly popular in industries such as oil and gas, chemical processing, marine, and pulp and paper.
10. 316L stainless steel is a commonly used grade of stainless steel known for its corrosion resistance, high strength, and versatility. It is an austenitic stainless steel alloy with low carbon content, making it suitable for various applications where resistance to corrosive environments is essential. It is widely used in marine applications, chemical processing, dairy, and pharmaceuticals.
10. 304L stainless steel is a commonly used grade of stainless steel known for its corrosion resistance, versatility, and ease of fabrication. It is an austenitic stainless steel alloy with low carbon content, which enhances its weldability and reduces the risk of sensitization to intergranular corrosion. In comparison to 316L SS, 304L SS has no molybdenum content and it&#;s less resistant to chloride-induce corrosion. It is suitable for general-purpose uses that don&#;t require the enhanced corrosion resistance of 316L SS.
12. LEAST EXPENSIVE: Carbon steel is a type of steel that primarily consists of iron and carbon, with other elements present in smaller amounts. It is one of the most commonly used materials in the manufacturing and construction industries due to its affordability, strength, and versatility.
Typically, the higher priced alloys are also in shorter supply, due to lower demand and the higher cost of carrying inventory. This directly affects the lead-time of these materials, often by 2-4 times that of more common alloys like carbon steel and stainless steel. Quantity of these higher alloys can also greatly affect price. Steel mills typically don&#;t run small batches of tubes or plate or they will charge for the entire mill run if they do.
Contact us to discuss your requirements of astm a511 stainless steel hollow bar wholesale. Our experienced sales team can help you identify the options that best suit your needs.