Table of Contents
What you will learn with the Copper Versus Aluminum Coils HVAC article:
1) The transition from copper to aluminum for HVAC manufacturers.
2) The pros and cons of copper coils versus aluminum coils for air conditioner systems or heat pumps.
3) Trying something new or keeping the status quo?
4) A video debunking the “aluminum is difficult to repair” myth.
5) Lastly, plenty of resources and in-depth related links to help you learn
The Conductivity of Copper Versus Aluminum Coils | Copper Versus Aluminum Coils HVAC
When it comes to Copper Coils Versus Aluminum Coils for Condensers and Evaporators, what is the best choice? What are the options if I’m a consumer? Some manufacturers are starting to transition from copper coils to aluminum coils for both condensers and evaporator coils for various reasons.
Origins of Copper and Aluminum Discovery | Copper Versus Aluminum Coils HVAC
Copper coils covered with aluminum fins
When deciding to buy a new system, you need to inform yourself about the pros and cons of purchasing a system with aluminum coils or copper coils. Traditionally, copper was the chief choice to use to manufacture evaporator coils and condenser coils because of heat transfer rate, cost, pliability (easy to bend and swage), and because copper line sets are used to join split systems.
Moreover, the price of copper has skyrocketed, and that was a game-changer. Furthermore, many manufacturers have started looking at aluminum because the cost of aluminum is cheaper than copper, and aluminum has some of the same benefits of the properties mentioned above that copper has.
Copper Coil Vs Aluminum Coil Heat Transfer Characteristics
A copper coil has approximately twice the conductivity of heat transfer of an aluminum coil and therefore is more efficient at transferring heat. An air conditioner or heat pump works on the principle of refrigeration. The classic definition of refrigeration is moving heat from one place where it is not wanted to another location where it doesn’t matter. Finally, that means it is crucial to use materials that efficiently move or transfer heat. In this regard, copper wins. Refrigeration is what makes air conditioning systems work.
Furthermore, another pro for copper coils is the ease of repairing the copper coil in the field if they become damaged. Finally, aluminum coils, if damaged, are tough to fix and often need to be replaced.
Pros and Cons of Copper Versus Aluminum Coils HVAC
Manufacturers producing copper pipe with thinner walls
- Heat Transfer
- Repair Ease
- Galvanic Corrosion
- Formicary Corrosion
- Material Quality/Durability
- Aluminum Repair Ease
- Copper Durability
- Copper and Aluminum Together
- Tradition
Heat Transfer
1Copper has a better heat transfer rate than an aluminum coil
Repair Ease
2A copper tube is easily repaired in the field when damaged whereas an aluminum coil, when damaged, typically requires an entire coil change
Galvanic Corrosion
3Because the copper tube line set, copper coils, and fins are aluminum, where the copper joins the aluminum, it is subject to galvanic corrosion. Galvanic corrosion will occur when two dissimilar metals are pressed together. Furthermore, modern technology and advancements in joining dissimilar metals have made this con very minimal for aluminum.
Periodic Table of Elements: Copper is 29 and Aluminum is 13.
Formicary Corrosion
Copper is subject to formicary corrosion. Additionally, that is not a problem as long as the copper coil gets proper and regular maintenance.
Material Quality/Durability
4Modern technology and the price of copper have made manufacturers use thinner and thinner copper. The new refrigerant replacing the old HCFCs operates at higher pressures; therefore, the newer copper coil is more likely to spring a leak because of the thinner copper tube and the higher operating pressures.
Aluminum Repair Ease
5Because an aluminum coil is challenging to repair, air conditioner manufacturers use a heavy-duty cabinet to protect the coils. Lastly, that makes it more difficult to clean the aluminum coil without disassembling the cabinet.
Copper Durability
6The traditional perception is that copper is more durable than an aluminum coil, but again, that will soon change as the copper gets thinner and thinner because of the rising cost.
Material Theft
7Since copper is costly, it makes it a target for thieves. A contractor friend of mine just replaced some air conditioner condensers and all the copper the thieves could get their hands on, for a church. Now it’s bad enough they hit a church (imagine the implications of that in the afterlife. LOL). Still, it is now necessary to secure copper, including condensing units with copper coils, to discourage theft. Furthermore, that is an added cost for the end consumer.
Copper and Aluminum Together
8I have read that as much as copper suffers from formicary corrosion, aluminum suffers from bacteria and mold issues. The problem with that argument is that manufacturers have always used aluminum fins over the copper tubing to increase the area for heat absorption and to channel the air more effectively across the coils. Besides that, anyone with mold or bacteria problems need to use a UV Air Cleaner inside their ducts.
Tradition
9The traditional copper coils, copper tubing with aluminum fins have functioned for years and years in condensers and evaporator coils. These coils are tried and true, so anything new on the market is subject to some apprehension. Moreover, Trane has been using aluminum coils for years and years, and they offer a good warranty for their product, so aluminum coils can’t be that bad for use in HVAC equipment.
Condensing unit with copper coil & aluminum fins
Traditional Coils | Copper Versus Aluminum Coils HVAC
Additionally, refrigerator and freezer manufacturers have used aluminum coils for many years for the coils in their products. What is your opinion based on the facts? Leave your opinion in the comments below.
Finally, the below video is of a repair to an aluminum coil. That is in case of a puncture or leak in the coils. Furthermore, not sure how this stuff would work for joining two dissimilar metals together, such as copper and aluminum, but this is a plus for aluminum coils.
Copper Versus Aluminum Coils HVAC
Thank you Austin Air for a great explanation.
Would you mind commenting on the newer variable stage compressors and variable speed fans?
Thank you
Edward
I am a Texas Licensed HVAC contractor serving Katy, Texas area.
Trane, wasn’t the first to use all aluminum Evaporator coils. They were the ones who ‘Took Over’ General Electrics design of the spiny fin all aluminum condenser coil.
Back in the day, American Standard owned Trane mainly because when Trane bought GE in the early 80’s they over paid and was bought out by American Standard years later.
I installed a ‘state of the art’ American Standard system at my home in 2007. These systems did not employ an all aluminum evaporator coil. They were still copper & aluminum evap. coils at that time.
Goodman Manufacturing had all aluminum evaporator coils long before Trane or American Standard. Trane and American standard are more or less the same, slight difference in condenser fan shroud other than that the equipment is more or less the same with different branding.
With that said, all aluminum evaporator coils were made by Carrier Corp. in the 70’s. The problem at that time was keeping a good connection to the copper line set. They were connected using a special compression type fitting and over time this connection would fail. With no way to fix this leak, replacements to copper / aluminum fins would often become the result.
So what changed? The new found way to meld aluminum to copper as the line set leaves the evaporator coil plenum.
I can’t think of any manufacturer now that still makes a copper and aluminum fin evaporator coil. With that said, nothing is immune to failure. An aluminum coil can develop a refrigerant leak just as much as a copper aluminum evap. coil can.
It’s 2018: You will always need a good HVAC Repair man.
Why is it such a problem? refrigerant costs. Refrigerant used to be cheap, so cheap many companies would just consider it a form of over head cost. But now that the refrigerant (all refrigerant) has gone up so much, this is no longer the case.
I have installed hundreds of all aluminum evaporator coils. For the most part they are quite reliable. On the other hand I have also found failures (leaks) in all aluminum evaporator coils as well. Brand of coil doesn’t matter.
All brands fail. There is no such thing as a perfect brand. That is 23 years hands on experience fixing these kinds of problems.
Anyhow, copper coils are proven to be better than the traditional aluminum coils. From your write up, I came to know that the right choice of metals can do wonders in the industrial machinery manufacturing to a large extent.
I just wanna thank you for sharing your information and your site or blog this is simple but nice article I’ve ever seen i like it i learn something today.
Pretty good post. I just stumbled upon your blog and wanted to say that I have really enyed reading your blog posts. Any way I’ll be subscribing to your feed and I hope you post again soon
I purchased a 3 ton Trane A/C system for my home in 2013. Recently I have had problems with a clogging drain line due to a slimy, sludgy substance that I understand is created on the aluminum coils due to some chemical action and in addition the substance formed has a bacterial/microbial nature to it which can be harmful to ones health. My wife has a incurable lung bacteria related to TB and I am concerned about her well being under these circumstances. Trane has suggested tying a piece of copper tubing on to the aluminum tubing. Are they serious? The dealer suggests, install a steeper inclined drain line to help the substance exit the system. That seems to me to be treating the symptom and not the problem. Any suggestions on a remedy?
UV air cleaner along with an electronic air cleaner and a decent filter? Also regular treatment for mold and algae in the drain pan is good.
Are they serious? Copper kills the bacterial/microbial stuff. They should have gone to all copper coils instead of all aluminum.
” The cost of copper has sky rocketed”, that’s a lie from a web site that is dedicated to educate without bias facts for the HVAC community ? One just has to look at the price of copper per pound over the last 3 years it has gone down,down ,down . The real reason is that HVAC companies has spread this “cooper increase ” lie is so that they can justify their use of aluminum , a cheaper, less durable material that gives these companies higher profits.
This article was written a little over 3 years ago when copper was going through the roof as far as costs are concerned. And I can attest to you that the cost of copper was very high even for the consumer at that time. I myself prefer copper over aluminum but being fair about things refrigerator and freezer manufacturers have used aluminum for years and years and there are many refrigerators and freezers still chugging along after many years. My overflow fridge in the basement is over 30 years old and still does a nice job keeping things cool. It has aluminum coils. I know we are talking about AC’s and Heat Pumps but both copper and aluminum have proven their durability over time. The preference for copper over aluminum for me is a few things but namely the ease of repair.
I purchased one of Tranes new type all aluminum evaporator coils for my 5 ton unit. It is huge and I paid a premium for it over a copper coil thinking that I would get extended years life out of it. Nine years later it is leaking and I am in the process of replacing. Very disappointed with Trane and the so called premium aluminum coil system that they sold me. The warranty was only for 5 years. Will be switching back to copper evaporator coils.
I think, though I’m presuming, the heat transfer ability shouldn’t be too terribly relevant itself, unless you have some extreme space limitations. But heat conductivity perhaps not entirely irrelevant in general. There are so many considerations in the design of the coils (area/thickness/etc), I cant say, but I might guess that all copper design might be a bit smaller for the same heat transfer purpose. I don’t think coolant is a health issue as some may have mentioned. There is practically no leaking at all of course. As in no molecules at all or just a few. Any leak so small as to allow unit to operate for any length of time I think we could probably presume is undetectable by humans under any conditions, including undetectable by human immune/inflammatory system. All that said, I think copper is just a better choice of metals based on the entire set of considerations, including organic growth on evaporator coils, but I personally suppose the magnitude of that growth consideration may not place it as the biggest deciding factor. Some swear alum is as good or better, I suppose it’s very complicated and difficult to truly compare 1 to 1.
Life of Copper Condensor is more then Aluminum Condensor….
And chances for leak in Copper is much less compared to Aluminium….
Agreed. I rarely heard of a leaking evaporative coil assembly until after 2008. Now, it’s far too common. And, quite costly to repair.
You have correctly distinguish between aluminum and copper. Aluminum is cheaper and can be used in many applications due to its flexibility and durability. Thing to be noted if we are getting same properties of copper as in aluminum than why to go with the spend more making investment in copper.
perhaps spend more for copper precisely because of the previous comment.
In car a/c all manufacturers stoped to use copper since last 10 year .Yet there is not any problem in AC EVEN IN MOST EXPENSIVE CARAS where we must have no choice but to accept the aluminium condensed car . so why shouldn’t we accept in our home AC which is cheaper by almost 25% than copper condensed AC. B.JADAV
It’s basically a health question. Manufactures have solved a corrosion issue and reduced their costs by going to all aluminum coils. But as in many other cases, the use of a materials to solve one problem or reduce costs can sometimes lead to other problems down the road that were never considered.
The following was extracted from a study done at the University of South Carolina and supported by the U.S. Army. (“Characterization and Control of the Microbial Community Affiliated with Copper or Aluminum Heat Exchangers of HVAC Systems”; Michael G. Schmidt, et al., 2012. DOI 10.1007/s00284-012-0137-0)
“In densely occupied buildings, airborne microbial contaminants
can result in numerous adverse effects on human
health and well-being, including inflammation and infections.
Airborne bacteria and fungi have the potential to
adversely impact human health by causing infections,
allergic responses, or toxic effects. Thus microbial growth
in heating ventilation and air-conditioning (HVAC) systems
and subsequent contamination of the indoor air
environment is of increasing concern.”
“copper profoundly inhibited the concentration
and diversity of microbes associated with the biofilms
formed. The extent with which copper limited the
growth of bacteria was 99.99 % and the limitation of
fungal growth was found to be 99.74 % of that observed on
the control, aluminum based heat exchangers.”
In other words, the bad stuff can’t grow on copper.
After reading all the comments and concerns, I’m still confused as to which is the better choice: Copper or Aluminum
I would stick to copper as a preference over aluminum.
Yes….But will the government and merging corporate manufacturers allow us that choice? It even seems that the new copper tubing is not of the old quality. All the old American milled scrap was sent to China , melted down an sold back to us possibly adulterated with mystery metals, hard spots, and does not seem as ductile as it once did. I am a hvac tech, not a conspiracy theorist.
Copper Versus Aluminum Coils – Condensers and Evaporators
Name: Don Riggs
Comment: I tried to leave the following comment on your Copper versus Aluminum Coils Webpage:
Note to Viabhav Sethia:
Thermal Conductivity, Btu/hr-ft-degree F
Aluminum alloy 1100: 128
Copper electrolytic: 227
Source: 2001 ASHRAE Fundamentals Handbook
Therefore, Copper is 1.7 times more heat-conductive than is Aluminum.
Only increasing the size (area) of an all-Aluminum coil set by more than 1.7 can you gain more heat transfer over an all-Copper coil set.
Thanks Don……………we have been having issues lately with tons of spam and security so our settings for security has been increased. Sorry about the issues you had posting and thanks for letting us know this tidbit of information. We encourage our readers to contribute in either comments or by submitting articles. Thank you!!
To the ladies who posted about the metallic smells and sick symptoms, I strongly suggest you have your home inspected to see if it was built with Chinese Drywall. Do the research on this, and you may have your answer. We bought a new home in VA in 2004 that was built with this drywall. Not every wall contained the drywall; as the builder alternated half Chinese and half American made drywall throughout the home. It took a handful of inspections to catch it, but we did. We moved outta there immediately. It’s been years, and my health is still not straight from living in that contamination. 🙁
What a con. Most of the people who live on the coast will need all copper Evaporators and Condensers and plumbing which after having a protective coating applied as well aids in its thermodynamics and proven better than non coated and easily repaired. And the all Aluminium equivalent uncoated is in second place. Not all these mixes of copper and Aluminium fins which will never stack up with strength, longevity or thermodynamicallly. How much would it truly cost to have 100 percent copper on both Condeser and Evaporator with Hydrophilic coating on both and self cleaning modes on both units,Hot dipped Galv /Powder coated cabinets and Protective coated circuit boards with Militery grade components. We are fed B/S ALL THE TIME AND LIED TO BY MARKETTING. I would pay an extra $250 to have all this and save it 10 fold in repairs,running costs & longevity down the track. marine grade 316 hardware used as well. How much Would this copper cost to have copper fins? Even if Copper prices are higher its marginal on an A/C unit to do our homes. Even Military grade electronics won’t add much in mass production.
Everyone is waiting for you to start a company and build what you are talking about here. This should give you the competitive edge over everyone else.
Thanks for your reply! The unit is not a heat pump, and the contractor said he’d get back to me this week and try to resolve this. And this is definitely not dirty sock syndrome. I’ve not run the a/c for a week and the blower has been off for three days. There’s a metallic odor throughout the house, although it is not the same as when the blower runs. I don’t get a headache now, but my nose still runs a lot.
The contractor said that their Trane contact mentioned the armaflex insulation with its Microban impregnation as possibly causing an allergic reaction. This covers one of the lines that runs between the evaporator and condenser (cold R410-A refrigerant in liquid form?). This might explain my runny nose when I’m inside the house — even when the blower isn’t running (and hasn’t run for several days). I’ve gone down into the basement to sniff but notice no particular odor, not even the aluminum odor I smell everywhere upstairs (the a/c lines run between floor joists in the basement ceiling and exit at ground level at the back of the house, where the compressor is located).
So I’m perplexed. Data sheets for the refrigerant R410-A describe leaks as causing symptoms exactly like mine, and specify an “ethereal” odor for the product that MAY be what I’m smelling –a smell very, very faint when the a/c and/or blower runs. But this is different from the strong aluminum odor I smell upstairs when the system is completely turned off.
Another concern I have is that the contractor will replace the evaporator coil or repair a leak, if one is found, and I’ll still have symptoms related to the strong aluminum smell or the armaflex/Microban combination.
Is anyone familiar with allergies related to Microban or Armaflex insulating tubing, or with allergies to aluminum? My Trane furnace has an aluminum heat exchanger and I’ve had absolutely no problems with it these last five years, so I’m perplexed.
Thanks in advance for any information or insights you can provide.
Kim, did you ever figure out your problem or find a solution? We are having similar issues.
We just had our air conditioner repaired and the new aluminum condenser coils installed and the traditional copper/aluminum coils removed. I am having a terrible time adjusting to this all aluminum system – seems it is causing me to be sick to my stomach and leaves a taste in my mouth. I am indoors most of the time. We left the area for three days and I immediately felt better. Now I am back home, and am getting the same taste and weird feeling in my stomach. Has anyone else suffered these symptoms from the aluminum coils. I am highly allergic to metals, yet I never had any problem with our old system, so am thinking it is this new all aluminum coils system putting something in the air?
Some people have problems with heat pump coils and the odor. Its called dirty sock syndrome and does not effect every heat pump. I have never heard of anyone having issues as you describe.
Copper Versus Aluminum Coils – Condensers and Evaporators
I had a new air conditioner installed on July 2nd. An evaporator coil was installed in the plenum above my Trane furnace (on a shelf the technician installed for this five-year-old unit). Since then, I have gotten a runny nose, burning eyes, and a headache whenever I run the a/c or even just the blower (which my installer recommended I run 24/7). I’ve asked about sprays that might have been applied to the evaporator at the factory to preclude bacteria problems, but Trane claims that they don’t use these sprays. My symptoms are distressing to the point that I’ve run the a/c less than a dozen hours since installation, and the blower on and off for only part-days (mostly times when I’m away from home – hoping to “break in” the system and eliminate any “new unit” smells).
The installer visited my home and I ran the system for him. He didn’t smell anything, and was not on site long enough for a headache to develop. The odor is very faint, which led me to believe that if this isn’t an antibacterial spray, it may be a refrigerant leak (look up info on R410-A and you will find the term “ethereal” used to describe the smell of the refrigerant). Several of my neighbors and friends can smell this, some cannot, and two who are especially sensitive to odors had to leave the house after 10 minutes.
Even when I don’t run the a/c, or even the blower, I can smell aluminum, or some kind of metal. When I turn the blower on this smell is displaced by the faint odor I mentioned above…and within a half-hour my nose starts to run, my eyes burn, and I get a headache.
This article’s mention of epoxy used to join the copper refrigerant lines to the aluminum coils offers another avenue to explore, and makes sense (Thanks!). Possibly, I’m reacting to this chemical, as the connection of copper to aluminum is made inside the plenum right above the heat exchanger and blower.
I don’t how to respond except to say some people have a problem with what is called “Dirty Sock Syndrome” where the smell is like dirty socks. Trane does make a coil that is coated in Teflon or some other substance to prevent that and this problem usually only occurs in heat pumps. Is it a heat pump? If so then I would inquire about the specially coated coil even if there is a charge to have it installed. I know some companies go above and beyond to make sure they keep their customers happy. Plus, if have done your research well I am sure you have found something about dirty sock syndrome as I believe I address that issue here on this site as well. Good luck and I hope you get your problem resolved.
Do you know if any of the gas pack manufacturers are utilizing coil/fin sealers as a method of protection against galvanic and formicary corrosion? And if so, how well they actually work?
I think all the manufacturers are going to aluminum with Trane leading the way. The engineering of new sealers/epoxies to join the copper to the aluminum has advanced to the point where manufacturers are comfortable with it enough to offer the warranties on their equipment. Not 100% sure about the gas packs but check with each manufacturer to see what they are using.
Compared to aluminum, copper significantly limits the growth of bacteria and fungus. I’m thinking having some copper around to inhibit the growth of bacteria and fungus has to be a good thing. Does anyone know how the manufactures of all aluminum coils address the problems of bacteria growth on their coils (better known as dirty sock syndrome)?
Even the copper coils have aluminum fins unless you special order copper coils with copper fins. Some manufacturers offer a specially coated coil to prevent dirty sock syndrome. The coating slightly inhibits the heat exchange process however you do not experience dirt sock syndrome.
Hi. I think most facts mentioned by you are accurate. However heat transfer is better on multi channel aluminium condenser.
Thanks for letting us know that fact about aluminum.