Sv: Alum. vs Copper RE: I need a radiator for an 88 80q , where to buy?????

["Claus Vegener" <vegener@post7.tele.dk>]

Talking Thermal Conductivity Kenn is right, but the biggest problem
in heat transfer is not transfer of the heat from the innerside of the
CU or Al tube through the metal and to the outher side of the finns.
It is the crimping of finns CU or Al to the inner tube and the
extern heat transfer coeffcient [W/(m2 * dT)] for the air, which is the
heavy one.
And besides:
The resulting effectivity of  fin's of equal sizes depends on the square rot
of
their thermal conductivity. Hense the advantage of Cu to Al is
(390/239)^.5 = 1.28
The Cu fins should be 28% better but is more heavy and more expensive.
So look at the area, number of fins and the tube surface, if you have to
compare 2 radiators.
In the first step from inner tube to outer tube the material don't matter.

Kind regards Claus

----- Oprindelig meddelelse -----
Fra: Kenn Thyrsted <thyrsted2@olsy.dk>
Til: Avi Meron <avi@cosmoslink.net>; <River6822@aol.com>
Cc: Quattro <quattro@audifans.com>
Sendt: 24. juli 1999 00:30
Emne: Re: Alum. vs Copper RE: I need a radiator for an 88 80q , where to
buy?????


> Actually Copper is better than Aluminium.
> Cu=390W/(m*deg)
> Al=239W/(m*deg)
>
> Ordinary Brass (Yellow) is 112W/(m*deg)
>
> /Kenn
> ----- Original Message -----
> From: Avi Meron <avi@cosmoslink.net>
> To: <River6822@aol.com>
> Cc: Quattro <quattro@audifans.com>
> Sent: Friday, July 23, 1999 7:26 AM
> Subject: Alum. vs Copper RE: I need a radiator for an 88 80q , where to
> buy?????
>
>
> > Scott,
> > Aluminum dissipate heat much better and faster than brass or copper, you
> can
> > get away with an alum. rad. that is smaller than brass, that is one of
the
> > main reasons while most (almost all)OEM radiators and AC evaporators are
> > made out of alum.
> > If you have difficulty with my statement try to heat a copper pipe and
and
> > alum, pipe, you will find out very quickly which material conduct heat
> > better. The only advantage that brass has over alum. (rad.) is
durability.
> > Avi
> >
> > -----Original Message-----
> > From: owner-quattro@audifans.com [mailto:owner-quattro@audifans.com] On
> > Behalf Of River6822@aol.com
> > Sent: Thursday, July 22, 1999 7:51 PM
> > To: obin_olson@hotmail.com; quattro@audifans.com
> > Subject: Re: I need a radiator for an 88 80q , where to buy?????
> >
> > You will not find a new radiator for less than $175. I put one in my 88
> 80q
> > about 6 months ago. What a PITA. I got mine from a local radiator shop
> that
> > carried a generic brand-- i'm not sure of the name. The shop is in
Glasco
> > NY,
> > I don't know where you are located. Anyway, I know it was not a Modine.
> >
> > The radiator is a copper core, the original is aluminium. Don't let
> anybody
> > fool you, copper disappates heat faster than aluminium. It has been
> working
> > fine and the running temperature is below what the old radiator ran at.
> >
> > Hope this helps.
> >
> > Scott Calabrese
> > 88 80q
> > http://members.aol.com/river6822
> >
>