Aluminum vs Copper coil

[Bevill]

I live in FL and am in the process of getting estimates to replace a 22 year old Trane heat pump. I've already spoken with a Carrier dealer and one of the points they brought up was the composition of the coil. He mentioned that their coils are copper and can be fixed vs aluminum coils which need to be replaced. I've tried searching the forums but couldn't find a similar topic.

Is there a general consensus on this or does it really not matter?

[amickracing]

I would say it's not a huge factor. Most new coils will last a long long time with out ever leaking (provided they are installed right and cared for).

Copper coils are a PITA to repair anyway, especially if the leak isn't out in some exposed area, and if it's hard to get to, it's best to replace the coil anyway.

So... I don't think it'd be enough of a choice to make the decision on.

[BaldLoonie]

Trane is the only one using aluminum. Their outdoor coils are the old GE designed Spine Fin which is a continuous tube of aluminum. Only way that will leak if if something rubs or punctures, hard to do with the protective cabinet. Trane went to all aluminum indoor coils recently and bumped up their warranty to 10 years. The industry has had trouble with leaks from corrosion and the 1 metal coil should stop that. The Carrier dealer has no room to talk, his indoor coils most say are the most likely to leak :rolleyes:

[gevans]

I have not had much success repairing aluminum tube coils. You can't always fix a leak in a copper coil, depends on the location, but most of the time you can. It still might make more sense to replace it than fix it, tho.
An aluminum coil will not stop metal corrosion due to joining different types of metals unless you also use an aluminum lineset and an aluminum compressor, reversing valve, etc. Copper is more efficient at heat transfer, but it costs more. The manufactures can overcome the heat exchange difference by making the aluminum coil slightly larger, defeating the cost savings.
And when your system finally dies... aluminum coils are worth more than mixed metal coils at the scrap yard!

[mr big]

Having been involved with the distribution of both for 30 years & involved with thousands & thousands of systems; there is no doubt that the Trane/GE Spine fin all aluminum coil is by far the most reliable ever made. There is also no doubt that the Spine fin coil will hold up much better in salty enviroment.

[jerrygr]

I am a Florida Contractor, central on the East coast. I have worked from Miami to Melbourne with over 30 years in the trade, first as a Tech and now as a contractor, that said: I have seen units rust away within 1 year and I have some that have lasted 15 years, copper or aluminum coils, these installed on the beach. I have used almost every coil coating sold and all work to a point. The only problem I have is explaining to customers why the high end units don't last anylonger that the cheaper stuff. As with evap coil drain water leaks find the cure and retire rich.

Trane requires that you have their coating put on the outdoor coil within a certain distance from salt water if you want extended warranty, goes by zip code. The "non major" brands don't require this. I don't sell Carrier so I don't know about them.

There is not an answer as to which is best, live close to salt water and it is a gamble as what brand you buy.

[mark beiser]

Trane's all aluminum indoor coil does away with the possibility of the #1 cause of evaperator coil leaks occurring, formicary corrosion.

http://www.edwin-fine.com/air_con/formicary_corrosion/formicary.html
http://www.arti-research.org/research/completed/exec-summaries/50055-es.pdf

This type of evaperater coil leak is not repairable, or at least pointless futility to attempt to repair.

As for any supposed cost savings of using aluminum tubing instead of copper, that is kind of eaten up in the manufacturing cost. It costs more to manufacture an aluminum coil...

A hole in an aluminum tube can be repaired just fine, it just isn't as easy, and uses different materials than repairing a hole in a piece of copper.

If for some reason a leak develops in the aluminum outdoor coil, Trane has a repair kit for it that works very well as a permanent fix if the instructions are followed...

If you are near a coastal area, a unit with an all aluminum condenser coil and composite base pan is going to last longer than one with a copper tube coil and/or sheet metal base.
If you live right on the beach, all bets are off with any metal though, lol.

[amickracing]

Speaking of....

I wonder if Trane will ever make a spline fin indoor coil?

[mayguy]

Speaking of....

I wonder if Trane will ever make a spline fin indoor coil?

They got it.

[mark beiser]

Speaking of....

I wonder if Trane will ever make a spline fin indoor coil?

The PTAC units used to have a spine fin evap coil, not sure if they still do.
It probably wouldn't work that well in the typical split system though, may have problems with how the condensate runs/blows off them.

[BaldLoonie]

I think the Spine Fin evaps went away when GE stopped making Zonelines. They also used Spine Fin on window shakers. We had one from the early 60s with it. Couldn't do it in an A coil however.

Here's a new all aluminum A-S/Trane evap: