Copper coils or aluminum?

[thinshavings]

Will soon be seeking bids on a new A/C system. 
I haven't purchased one in many years so what is the opinion on coil material?

[blackhat]

Copper, copper or copper.  Otherwise, get a wet towel and a fan.

[Robert Adams]

Pretty much all are aluminum evaporated coils. Personally I prefer copper but the copper used in coils has gotten much thinner to improve efficiency however the pressures are also much higher today which makes it easier for a coil to fail. Evap  coil failures are a pretty common issue now with no real end in sight unless the system pressures could be lowered. Not to mention the higher incidences of moisture causing internal corrosion with current refrigerants and oils. Much more temperamental these days and often a shorter life even when done right.

[thinshavings]

Pretty much all are aluminum evaporated coils. Personally I prefer copper but the copper used in coils has gotten much thinner to improve efficiency however the pressures are also much higher today which makes it easier for a coil to fail. Evap  coil failures are a pretty common issue now with no real end in sight unless the system pressures could be lowered. Not to mention the higher incidences of moisture causing internal corrosion with current refrigerants and oils. Much more temperamental these days and often a shorter life even when done right.

I've been reading about the short life of copper evap coils with some manufactures products possibly due to thin materials.

[blackhat]

There's a bunch of reasons, from economy of material, efficiency and poor quality material.  Best bet is the best warranty you can find if the dealer is there to back the warranty.  Shop shops.

[daddo]

I just replaced an old R22 system where the indoor coil was copper. After over 20 years, the coil still had no rust and looked good. It was an off brand with no tags. I wished I could ID it- I'd use their coils!
I also just replaced another R22 copper indoor coil that was only 9 years old- it was rotted out with rust and leaking- Goodman brand and this was the second coil since the system was new 14 years ago. I've had the same happen to a Trane copper coil. I wonder about corrosives in the home. Bleach, ammonia's, and so on.?
I've had better luck with the aluminum coils so far. With aluminum, the system must be more free of any moisture- poor practices will cause problems. The higher pressures with 410a doesn't help.

 In my opinion, it's pot luck. Until another refrigerant is going to be the standard and manufacturing materials are improved, we will continue to have problems and leaks will be a norm. A system that lasts 20-25 years with minor problems is in the past. The release of 410a refrigerant, more costly repairs, more frequent repairs, more equipment manufacturing, more resources being used-  all in the name of saving the planet and reducing energy costs. Ironic, isn't it?
When I find a system low on refrigerant, I usually first suspect the indoor coil.

We have indoor and outdoor "micro" coils now. They are keeping some guys very busy as well.

I still have an R22 system and I'm keeping it until it drops. My indoor Trane copper coil is from 1994 and practically rust free and going strong. I kept it when I replaced my furnace about 4 or 5 years ago.

To be honest- we have been politically screwed.

[Admiral]

To be honest- we have been politically screwed.

Gee, I don't know about that, ozone depletion is pretty much recognized as a result of man's use of many chemicals, including refrigerants, and I know a lot of guys my age getting lots of clipping of skin cancer.  I don't think there's an option of going back to the good old days of AC, sort of like starting up atmospheric nuclear bomb testing again in Nevada......hey, one or two a year won't matter much.

[Robert Adams]

Gee, I don't know about that, ozone depletion is pretty much recognized as a result of man's use of many chemicals, including refrigerants, and I know a lot of guys my age getting lots of clipping of skin cancer.  I don't think there's an option of going back to the good old days of AC, sort of like starting up atmospheric nuclear bomb testing again in Nevada......hey, one or two a year won't matter much.

           Back when the old refrigerants were being fought against there was allot of misinformation and junk science against them. In the end we were forced to outlaw them by other countries as they were proposing fees against trade etc if we didn't follow suit. 
              Part of the issue is that r12 and 22 are heavier than air and the small amount  of chlorine that could actually make it to the stratosphere was nothing compared to the amount that made it there from the common household pool. 
             We ended up replacing these with two refrigerants that were multitudes of times worse as they are something on the line of 20x worse greenhoise gas than co2. 
       
                There was also a replacement for r12 that would have been great. It was called r134 (not 134a).It was a drip in replacement for r12 ad pressures and perdormance were very similar and was mmuch greener than 134a. However all these refrigerant choices are not about the enviorment but are about profits of patent holders of the chemicals. 

           To add to what Daddo said basically the (perceived) better for the environment  of 410a  is way more than offset by the fact that the new systems leak faster releasing a very strong greenhouse gas and end up needing more repairs which means more pollution from manufacturing and the garbage of new and used parts. 
         Even if the old refrigerants were worse than their replacements, in the big picture they were greener because systems leaked much less, lasted longer etc. It's of that going on these days where people see one small aspect and think by changing it they are helping the enviorment end up actually doing more harm than good. 

            Those of us that did all the research and reading back when they started the war against r12 and r22 saw through the $ and bad science but going "green" is about money not the enviorment. I'm all for reducing our impact but it needs to be done smart not at a business and social whim.

[fredhargis]

There's a bunch of reasons, from economy of material, efficiency and poor quality material.  Best bet is the best warranty you can find if the dealer is there to back the warranty.  Shop shops.

Following Blackhat's advice when I recently replaced on heating system (3 months ago)the Carrier dealer was one I used before and trust more than others, but they (carrier also offered 10 years parts and labor on their system; some of the others offered 10 years parts but none had labor. I think Water Furnace offered the 10 years labor for a price, but Rheem and Lennox did not (the other players in my  estimates).