All aluminum versus copper/aluminum coils for air conditioner?

I have spoken with several HVAC contractors regarding replacement of my old Lennox central air conditioning system. All of them are Lennox dealers except one who also carries Trane products.
The dealer who also carries Trane was trying to switch me from my original Lennox preference, stating that the Trane coils, which are 100% aluminum, rather than the Lennox coils, which use aluminum fins and copper tubing, provide a better, longer lasting design.
He felt that Trane was superior in other ways also, since they used "composite plastics" in the outdoor condensing unit case rather than steel to ensure that no corrosion or rusting would occur.
The basic claim was that Trane, using aluminum for all of the refrigeration loop, had a longer life expectancy that Lennox, given the newer Puron refrigerant.
Does anyone have any experience with Trane, and is there any science to support this type of claim or any other prior experience to say that Trane is somehow better?
Thanks for any advice.
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On Sat, 31 Mar 2012 11:06:48 -0400, "Stormin Mormon"

It has been on the market for years. It is cheaper to build, more difficult to field repair.
All aluminum coils were starting to come into play in the late 1960's. I worked for a company that made HVAC units until 1970 and we made our own copper tubed coils and they started to buy aluminum coils.
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On 3/31/2012 3:09 PM, Ed Pawlowski wrote:

Thanks Ed for your reply and information. I just noticed that you have taken the time to provide useful and helpful information which I appreciate very much, and I am going to go with the copper / Lennox approach. My very limited experience working with aluminum leads me to the same conclusion you state and copper seems like the better choice. I am guessing that aluminum is becoming popular more as a result of rising copper costs than other, technical reasons.
Thanks again.
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I didn't think you saw what I wrote.
Christopher A. Young Learn more about Jesus www.lds.org .
wrote:

Thanks Ed for your reply and information. I just noticed that you have taken the time to provide useful and helpful information which I appreciate very much, and I am going to go with the copper / Lennox approach. My very limited experience working with aluminum leads me to the same conclusion you state and copper seems like the better choice. I am guessing that aluminum is becoming popular more as a result of rising copper costs than other, technical reasons.
Thanks again.
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On 4/1/2012 6:58 PM, Stormin Mormon wrote:

reply now that I have read it. My gut reaction closely follows your advice and opinion, and I am committed to copper for this next a/c unit.
Tonight I did find this article (see link below) from a company which apparently offers (only) aluminum and not copper heat exchangers / coils, and they offer claims that aluminum is superior, but I am not convinced. If they offered both and showed the relative benefits of each, I might find it more convincing.
I guess I am both too old and also too old-fashion to get very excited about an all aluminum solution. Since Trane is the only A/C manufacturer using it as far as I know, I have to believe it is not the obviously better solution, especially given the relative costs of copper versus aluminum.
Thanks again for replying.
http://www.hydro.com/en/Subsites/Hydro-Aluminium-Precision-Tubing/HVACR/Hydro-FAQ/Comparison-of-aluminium-and-copper /

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This, IMO, is the most important line of the story: "Thus, together with the cost savings of replacing copper with aluminium, the accumulated benefits of switching to all-aluminium heat exchangers are considerable."
It about the money.
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It's always about the money, but saying that doesn't tell you much. Silver is a better conductor than copper. I don't have a Trane system, but I wouldn't avoid one because it uses aluminum coils. Trane markets their Spine-fin aluminum coils as a selling point. They've been selling them for outdoor units since 1968. The coils are only one part of a system. I don't know the cost difference between the manufacturers. I would grill some *good* HVAC guys to find out about his. You don't want somebody selling you a crap system with a lousy compressor and inefficient operation because he brags "This unit has copper coils." BFD.
In this thread it's said aluminum heat exchanger manufacturing cost eats up the savings vs using copper. http://hvac-talk.com/vbb/showthread.php?t 9016 But that thread is from 2007, when copper prices were lower. Here "something" more. Probably all marketing BS. www.sapagroup.com/pages/26202/sapa_hvac_white_paper.pdf
http://www.alcoil.net/applications.htm
Anyway, there are SEER ratings, and HVAC guys who have long experience with this. Whether it's aluminum or copper is just one thing to consider. My furnace and central air is Rheem. Except for getting the main board replaced, it's all worked fine for 13 years. Why do I have a Rheem? Because my brother was a GC then, needed the work, and had a HVAC installer sub who needed work. They decided I got Rheem.. Maybe I could have done better on the cost by shopping, maybe not. But hey. what goes around comes around.
--Vic
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On 4/2/2012 9:14 AM, Vic Smith wrote:

motivation being financial, but really have no good way to compare reliability and failure rates in any other meaningful way. Consumer Reports seems to be silent on the whole matter of central A/C reliability. And even if they published historical data, the move to Purson and these much higher pressures may change the game entirely in terms of who has the better components in the long term.
Like most things, it will be a bit of a coin toss in the final analysis, but I wanted to see if this whole aluminum versus copper thing was a "red herring" thrown out by a dealer whose profit potential or other motives makes him sell both Lennox and Trane, and then recommend Trane for this specific reason of aluminum coils.
Thanks again!

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replying to Smarty, BobsYourUncle wrote:

This may have been true in 2012 but no longer is: http://web.consumerreports.org/airconditioners/v1/index.html?EXTKEY=SG72A00&gclid=CIvlkN-oz9QCFQEpaQodqHQFSQ
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replying to Smarty, eo wrote: I think that Lenox is moving to aluminum at least for a while until new copper coils with less problams are available. At least when the copper cil in my new ( september 2015) slp98 system went bad with six leaks they put in an aluminum coil
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replying to Smarty , Shep wrote:

I did a little research, and it seems formaldehyde forms formic acid on copper coils. Since the SEER minimum increase to 13, manufacturers started making copper coils even thinner, which leads to faster corrosion and holes caused by formic acid. Aluminum coils are not susceptible to this deterioration and holes from formic acid.
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replying to Ed Pawlowski , mj wrote:

I have a 3 year old Trane 4 ton unit. It has aluminum coil. It has been serviced 9 times for slime on the coils. I have been told that if it had some copper, like my two 1 1/2 ton units, I would not have this problem. My repair company is trying something new-laying pieces of copper tubing in the pan to try to stop the slime build up.
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On Thursday, October 8, 2015 at 2:44:06 PM UTC-4, mj wrote:

Interesting. I know copper is used in boat bottom paint because it's toxic to barnacles. Which leave one wondering how it's OK in copper water pipe? I guess very little leaches out? But if that's the case, how would having copper tubing in the coils kill slime? Zinc is used on roofs with problems to keep algae from growing. If you drive around here, you can see roofs where there is no algae on the roofs below flashings, vents, etc that are made of zinc.
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On 10/8/2015 3:01 PM, trader_4 wrote:

Science comes the full circle. Now they will come out with lead pills to deal with copper poisoning.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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On Thursday, October 8, 2015 at 2:44:06 PM UTC-4, mj wrote:

So here is an interesting take.
Whatever type of coil you have, water is the enemy.
Of course water will form from condensation when it is cooling.
So my take is that to reduce corrosion of the coil, set the blower to run all the time when you are using the AC.
This way when the compressor cycles off, the blower will continue to run and air dry the coil. You don't want the coil to sit there wet for no reason.
Mark
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replying to makolber, BobsYourUncle wrote: This will dry your evaporator coils all right, but it will also increase the humidity inside the house by as much as 10% as well as increase your energy usage. The evaporator coils that produce water condensation are inside the house, and are designed to both withstand and shed water, so water on them is not an issue. What we're talking about here are the condenser coils in the *outside* unit, which despite the name do not form water condensation, they condense the refrigerant in the lines back to a liquid which then makes the coils hot. The only water on the condenser coils comes in externally; rain/snow, sprinklers, etc.
So from a water perspective, the inside evaporator condenses water and the outside condenser evaporates it.
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caedfaa9ed1216d60ef78a6f660f5f85 snipped-for-privacy@example.com says...

But I have a heat pump and in the heat mode, it reverses and water and ice will form on the outside unit. That does not come from direct rain or snow.
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On 3/31/2012 8:47 AM, Smarty wrote:

As the original poster of this question, I am very sorry to see not a single reply............
This newsgroup really has become quite pathetic over the years, thanks to the combined efforts of those who think it deserves to be a place to discuss everything BUT home repair topics.
To the trolls who like to post about getting their cock caught in a carpet stretcher, to harry who insists on rambling about all things political to all the other folks who seem to think this is the right place to show their skills in endless threads about nonsense, I say a big FUCK YOU as you have effectively weakened the value of a very useful forum and made it into a garbage pile.
Maybe some new forum will arise where people with home repair issues won't be surrounded by these huge message turds which offer nothing of value to the average home repair person.
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You didn't see my post?
Thinking about it some more, well, I have read a bit about repairing aluminum, and it's a lot harder than repairing copper tubing. For that reason (as well as what I mentioned earlier), I'd avoid the aluminum unit.
Christopher A. Young Learn more about Jesus www.lds.org .
As the original poster of this question, I am very sorry to see not a single reply............
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On Mon, 2 Apr 2012 06:04:13 -0700 (PDT), " snipped-for-privacy@optonline.net"

He probably didn't see any from google groups. They went into limboland until today. Did for me anyway. A bunch of 3-4 day old posts just appeared.
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