Anodizing AL....thermal conductivity?

[javierb14]

as the topic states, im interested in how anodizing AL effects its thermal properties. the application in mind is a front mount intercooler or heat exchanger used on high performance automotive applications. does the anodization reduce the thermal conductivity? does it change for different types, such as normal or hard anodizing?

thanks

javier
do it right....don't go half-fast

http://www.full-race.com

 

[davefitz]

I am not sure about conductivity, but anodizing does radically change the surface emmissivity in the infrared range. anodized Al emmiss =0.85 versus normal oxidized emmis =0.12

 

[MintJulep]

I once used an allumnim aftercooler on an air compressor. Met the requirements I needed without any coating. Didn't after allodine coating.

I don't recall the specific figures.

 

[BlueBeam]

Anodizing means adding a layer of alumina to the surface. The thermal conductivity of this oxide is worse than for aluminium, but you always have a very thin layer.
The difference is only the thickness of this layer and it is interesting for the area of direct heat transfer. Here i expect better results with not anodized surfaces.
The other parts of the cooler, in contact with air(?), might have even an advantage if anodized. The alumina increases the "active area" of the surface due to the porosity - one reason that you get the higher emissivity of IR and maybe a better convection, too. The better mechanical properties of the anodized surface should be known.
Keep in mind that copper is mostly used in high performance thermal systems.

MT

 

[javierb14]

interesting, thanks for the replies. the reason for the anodizing is for more of a "sleeper" look.

here is an example

heat exchanger guts

javier

http://www.full-race.com

 

[javierb14]

for instance, this is a "sleeper" with a 20*10*3" anodized intercooler.

javier

http://www.full-race.com