Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

evaporator copper or aluminum better?

98audiA4 on Fri August 06, 2010 9:00 AM User is offline

i tried searching and didn't come up with much so maybe there is no clear answer.

if you were replacing an evaporator core is the a preference between an all aluminum unit and an all copper unit with aluminum fins?
assume the construction is the same the only difference being copper.
(the picture is for reference)


Edited: Fri August 06, 2010 at 9:02 AM by 98audiA4

98audiA4 on Fri August 06, 2010 9:02 AM User is offline

(fixed previous post, sorry for the double)

Edited: Fri August 06, 2010 at 9:03 AM by 98audiA4

iceman2555 on Fri August 06, 2010 5:54 PM User is offlineView users profile

Personal preference is aluminum. Several years ago when these type evaps were the norm, we often noticed a increase in vent temps when an OE alum was replaced with a brass and copper units. The difference is not excessive...but on a South FL scorcher...it can make a difference.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

TRB on Fri August 06, 2010 6:28 PM User is offlineView users profile

Quote
Originally posted by: iceman2555
Personal preference is aluminum. Several years ago when these type evaps were the norm, we often noticed a increase in vent temps when an OE alum was replaced with a brass and copper units. The difference is not excessive...but on a South FL scorcher...it can make a difference.

It will make a different how the feeder tubes are fixated. You can have a very well balanced core if it is configured correctly.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Cussboy on Fri August 06, 2010 10:00 PM User is offline

Quote
Originally posted by: iceman2555
Personal preference is aluminum. Several years ago when these type evaps were the norm, we often noticed a increase in vent temps when an OE alum was replaced with a brass and copper units. The difference is not excessive...but on a South FL scorcher...it can make a difference.

I think I'm going to agree with Iceman that aluminum will cool a little better, slightly better heat transfer.

That said, about 8 years ago I bought a copper evaporator (from the board sponsor, by the way) for my '88 Mazda B2200 truck, was half the price of a special-order one from Mazda and in stock (I'm in Phoenix, so I just made one trip to AMA to pick it up). For the Mazda aluminum part, I would've had to make two trips, one to pay, as that dealer doesn't do charge cards over the telephone.

Note that the original aluminum evaporator from Mazda did last 14 years before it got a hole in its center.


Edited: Fri August 06, 2010 at 10:01 PM by Cussboy

98audiA4 on Fri August 06, 2010 11:35 PM User is offline

thanks guys!

TRB on Sat August 07, 2010 2:11 AM User is offlineView users profile

I don't disagree with Ice. Just saying some T & F cores were made as cheap as they could. A proper tubed core will do a pretty good job. Think how many copper cores are in homes though out the world?

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

jglanham on Sun August 08, 2010 4:30 PM User is offline

The thermal conductivity of copper is almost twice that of aluminum, but aluminum is cheaper.

-------------------------
johnl

98audiA4 on Mon August 09, 2010 11:25 AM User is offline

i'm sticking with the original copper unit as it doesn't require me tearing apart dashes at the JY for an all AL one or buying a new one. seeing the two side by side did make me curious as to which is preferred by the experts. the way the small inlet pipes connect to the exchanger look to be done in a better fashion than the copper ones that i can say for sure. what i dont like about the AL one is the steel plates on the top and bottom that look to have rusted. no such issue on the copper one.

ice-n-tropics on Mon August 09, 2010 10:39 PM User is offline

According to the A/C guide "How To Air Condition Your Hot Rod" (available from Amazon), The coefficients of heat transfer are similar to the coefficients of electrical conductivity (page 10). The book says that the heat transfer of Cu = .0040 BTU/second but Al = .0020 BTU/second.
hotrodac

-------------------------
Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

Edited: Mon August 09, 2010 at 10:42 PM by ice-n-tropics

TRB on Mon August 09, 2010 10:43 PM User is offlineView users profile

Quote
Originally posted by: ice-n-tropics
According to the A/C guide "How To Air Condition Your Hot Rod" (available from Amazon), The coefficients of heat transfer are similar to the coefficients of electrical conductivity (page 10). The book says that the heat transfer of Cu = .0040 BTU/second but Al = .0020 BTU/second.

hotrodac

How do I get a signed copy?

-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

ice-n-tropics on Mon August 09, 2010 10:58 PM User is offline

If you pay close attention to the pictures, the length of the copper refrigerant inlet tubes are not well executed like the 4 aluminum 1/4" inlet tubes. The equal distribution of refrigerant spray (from the TXV) is dependent on both the accuracy of the machined 4 circuit distributor and the equal length/pressure drop of the 1/4" feeder tubes.
TRB
I'll give you a call when I get back from calvary Canada.
hotrodac

-------------------------
Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

NickD on Tue August 10, 2010 9:59 AM User is offline

Many different alloys of both copper and aluminum and efficiency is not the only issue, but long term reliability is also an issue. Judging by the amount of oxide on that copper shown in your photos, not exactly ideal. Cost wise in semiconductor heat sinks, can do a lot more cooling with a good aluminum alloy than copper, the formability is yet another issue.

Just way too many different variables just to simply ask if one metal is better than the other. Aluminum can be formed in ways that copper cannot, and if you make an evaporator or condenser of a given size more efficient with aluminum, that is the better choice. Problems with longevity with aluminum are directly related to the quality and the alloy of aluminum that was used. Can find far superior aluminum in a throwaway aluminum soda can.

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.