My Carrier air conditioning units are almost 9 years old and the copper
evaporator coils are totally rusted. I have an air conditioning guy that I
totally trust and he told me something interesting. He said that Carrier knows
that there are issues with the coils rusting out prematurely. Carrier use to
have all aluminum coils and aluminum never rusts. Carrier and other
manufacturers realized if they switched to copper coils their customers would
have to replace their coils approximately every 6 to 8 years (10 years if you
were lucky). So it all comes down to what's called "Planned Obsolescence" and
you see it practiced with almost everything you buy these days. It just puts
more money back in the pockets of the manufacturer and repair industry.
He also told me that Carrier and others are starting to bring back aluminum
because of the backlash from customers. I am now getting aluminum coils
a good friend from the 1970s who taught HVAC around here highly recommends goodman. they use standard parts that are commonly availble from many sources.
unlike trane and others that use OEM parts with no alternate suppliers, so they decide when a model is obsolete. they just quit supplying parts.
my goodman is working fine its 8 or 10 years old and came with a great warranty
replying to bob haller, BobsYourUncle wrote:
Also Amana which is basically a fancy Goodman, much as Lexus is to Toyota; same
manufacturer, just more bells and whistles (but without the extreme price delta
that the autos have).
On Saturday, April 18, 2015 at 10:44:04 PM UTC-4, mangino wrote:
Seems kind of odd that Carrier would switch to copper from aluminum
on the theory of making some more money. If your evaporator goes
at 8 years, how many customers are going to go with another Carrier
or even an evaporator replacement? At that point, most people are
going to get a new system and it likely wouldn't be Carrier. Also
given the cost delta between copper and aluminum, I find it hard
to believe it's even true that Carrier went back to copper coils,
unless there is some other valid reason for it.
Things have probably changes since I worked for a company that made
coils. Back then, they were copper and full aluminum was just starting
to be made by a couple of companies. The only reason they changed was
We had been making copper coils for many years and it would have been
costly to change over with all the equipment involved and we did not
make large quantities of a given size like Carrier. We did specialties
from 6" x 6" to 4' x 20' For tubing we used copper, brass, cupro-nickle
Yes there is another valid reason for the switch to aluminum (in addition to
planned obsolence) and it's called Formicary Corrosion. You can get the FACTS by
reading the industry research report containing scientific studies and analysis
going into the details of aluminum versus copper. These are details you won't
get from your air conditioning company.
Here's the link :
On Sunday, April 19, 2015 at 4:21:47 PM UTC-4, Ed Pawlowski wrote:
The facts here would seem to be that the document he just provided
is exactly opposite to what he's claiming. He stated that Carrier
allegedly switched to copper coils from aluminum so that they would
fail faster. Yet the document says Carrier is using aluminum coils
because they are corrosion resistant and superior. I don't see them
saying they went back to copper..... So, I don't see what all the
fuss is about.
I am sure that there are enough posters here to sustain *any* argument, with
or without facts.
When I saw the word formicary (formica means ant in Italian) I decided to go
look it up to see if it was related to ants (or Formica - which people tell
me stands for "FORmerly MICArta). This is another site that describes the
problem and claims it can occur within two months after manufacture.
<<Formicary corrosion is a type of corrosion also referred to by HVAC
contractors as "ant's nest" corrosion.>>
They say it can't be seen with the naked eye but I assume if any kind of
corrosion gets bad enough, it will become visible to normal vision.
Learn something new every day!
Formicary Corrosion can never been seen, it is the very definition of the pin
hole mesh; It is rare and is usually caused internally not externally with the
introduction of a acidic contaminant in the system.
Copper is tried an true, lasts for decades, provides 2X the heat exchange. (it
is the reason that ALL computer CPU cooling is COPPER)
Aluminum is cheaper and easier to bend; which is important because the MFG's
have to come up with creative solutions to make up for the reduced heat transfer.
Additionally, copper is easier to repair and unless the Aluminum system does not
have copper anywhere it is more likely to see corrosion where Aluminum touches
copper then copper has of Formicary Corrosion
You'd be surprized how many CPU heat sinks have absolutely NO copper
in them. I've even got a pile of them tat a magnet will stick to -
not very well, being stainless steel of all things (very poor thermal
conductivity, but goot thermal mass - with heat pipes to stainless
steel fins, plus folded fins that appear to be aluminum (definitely
not copper) fused to the stainless plate.
These all came from P4 and Core Duo equipped Lenovo desktop units.
Most of the rest of my stask are extruded aliminum -I had a couple
copper ones from ancient Dell PCs (Inspiron 2400??)
On Thu, 23 Jul 2015 21:00:23 -0400, email@example.com wrote:
I have a huge box of heat sinks from computers that date back to the
60s through P4 class machines and they are all aluminum.
The only copper I have ever seen is in a WYSE "thin client" machine
and it is a short 6 gauge copper wire that connects the aluminum CPU
heat sink to a much larger aluminum heat sink next to it.
I've got a bunch of heat sinks/cooling fans for CPUs and some of them did
have a highly polished copper insert that sat right on the chip (with
thermal gunk - amazing how much of a difference that stuff makes!)
But by and large they were mostly huge junks of aluminum. There were also
sinks that had a bracket that allowed use of a slower, quieter (and harder
to plug with dirt) 80cm cooling fan suspended over the CPU. I bought a lot
of spares and then switched almost exclusively to tablet PC's I got from
Ebay. )-: Not sure what to do with all those spares and for that matter all
the SCSI cards, 10Mb NICs, Archive tape controllers (a whopping 250Mb of
backup tape - huge for its time), old modem cards, ISA controllers, EISA
controllers, SCSI cables (I, II and III) and a host of other stuff from days
gone by. Did I mention my wife says I am a hoarder?
On Fri, 24 Jul 2015 13:18:04 -0400, firstname.lastname@example.org wrote:
I still have a stack of SCSI drives. I should plug them in and see
what I was doing way back in the 20th century. A couple date from the
day I retired in 1996 and have not spun since. These are the old
technology drives and I bet they will still work.
If you cut them open you will find that any decent heat sink for high speed
processors all have copper heat tubes and copper exchangers. They can have
aluminum fins but the heat exchange is copper, why? because copper has 2x the
thermal exchange of aluminum.
Also I find it interesting that the Carrier article is about evaporator coils
not condenser coils, yet its the condenser coils that are being changed to
aluminum while almost all of the evaporator coils remain copper.
Only heat sinks with heat pipes genereally have copper cores (because
they are a lot easier to braze and solder than aluminum)
I DO have a copper aftermarket heat sink I forgot about - and even IT
has a stainless steel thermal mass plate into which the4 heat pipes
are fitted. It's a "ZeroTherm" BTF95 (Butterfly) passive unit (no fan)
and also has a copper "transfer pad".
These tend to be used by the same geeks that buy "oxygen free" copper
speaker cables. The reviews tend to re-enforce my opinion - They dont
cool worth squat. (at $60 MSRP it does not outperform the OEM intel
aluminum heat sink)
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