View Single Post
Old 13th Sep 2017, 8:04 am   #24
Craig Sawyers
Dekatron
 
Craig Sawyers's Avatar
 
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,940
Default Re: Re-anodising heatsinks?

And from the Aavid heatsink manufacturer https://www.aavid.com/product-group/...ons-na/anodize

"Relatively large extrusions and those used at low temperature rise, as in many high power applications, will only gain up to 10% by the addition of an anodized surface.

With forced ventilation (using a fan) convective cooling is about 3 times higher than in natural convection. This changes the proportion of heat transfer due to radiation. An anodized finish will only add 4 -8% to the overall cooling effect in forced air. This percentage again, depends on fin spacing and heat sink dimensions. The color of the anodized finish makes little impact on emissivity since most radiational heat loss occurs at wavelengths higher than visible light.

As a thumb rule, if anodize is not required for aesthetic or corrosion protection, we suggest it only for small, open finned heat sinks in natural convection."

Craig
Craig Sawyers is online now