Air flow for a heat sink
Air flow for a heat sink
(OP)
Hi,
I am working on a project where I incorporated a parallel finned heat sink. The design right now has air flow, from a fan, parallel to the fin with regards to length. I now need to place the fan above the heat sink and have the air flow directly down on to the surface. A team member is telling me that the dissipation will increase with this design. I disagree with him and just wanted someone to back my assumption before I pull out my heat transfer book and crank out some numbers. Any help would be appreciated.
snowman
I am working on a project where I incorporated a parallel finned heat sink. The design right now has air flow, from a fan, parallel to the fin with regards to length. I now need to place the fan above the heat sink and have the air flow directly down on to the surface. A team member is telling me that the dissipation will increase with this design. I disagree with him and just wanted someone to back my assumption before I pull out my heat transfer book and crank out some numbers. Any help would be appreciated.
snowman





RE: Air flow for a heat sink
RE: Air flow for a heat sink
RE: Air flow for a heat sink
generally more efficient heat transfer possible in down flow, but you may need to increase the fan capacity to achieve dramatic increase in heat removal(dissapation).
RE: Air flow for a heat sink
Thank you very much for the input. I cranked out a few numbers and the air flow from above was the better choice. thanks again.
RE: Air flow for a heat sink
RE: Air flow for a heat sink
I've written a paper and article on the subject. It's at http://www.coolingzone.com/Guest/News/NL_NOV_2002/Biber/Biber_Nov_2002.html with an example at www.coolingzone.com/Guest/News/NL_DEC_2002/Cathy/Biber_Dec_2002.html.
One of the big reasons air flow from above is better could be that this configuration eliminates fan air flow bypassing the heat sink fin array.
Cathy Biber
Biber Thermal Design
www.biberthermal.com
RE: Air flow for a heat sink
RE: Air flow for a heat sink
RE: Air flow for a heat sink