I’ve been thinking about how to reduce the ‘audio’ from the small fan.
The first thing that came to mind, was using a Noctua 40x40x20 fan, which is listed at my local web-store as being 9.4 CFM - but according to Noctua’s web-site, it’s officially 9.4 CMH (Cubic Meter per Hour), which is around 5 CFM, so I scrapped that idea.
Instead, I found a small fan from Xilence (XF031), which might do the job.
-But I’d rather have an even larger fan running at lower speeds, so I looked around and found that Titan (a Taiwanese company) make some 60x60x10mm (TTC-CU4T2B) fans that have good specs: 22 CFM, 36dBA.
Looking at one of their heatsinks for 370 / 462 sockets, I got inspiration for drawing a heatsink for the fan (Attached).
I believe it can be made in a basement from a 3mm copper shet and a 0.5mm copper sheet.
Download: 60x60x13.5 mm Heatsink (SketchUp 8 file)
The fins need to be soldered onto the 3mm ‘base’, thus it would be good idea with a template to hold the fins in place while soldering (for even spacing). It’d also be a good idea to make a small bend-tool for the fins before starting.
The ‘funnel-ring’ at the top is only for experimenting with directing the air-flow. This part could be 3D-printed (need further work though, as it’s only a draft).
-If this is too much work for the hobbyist, it might be easier to get one of Titan’s 370 / 462 socket heatsinks and cutting / filing the bottom of this one to fit.
When soldering, the 3mm base must be heated to around 250 degree Celsius and touching it should of course be avoided. If you have a reflow oven and real solder-paste, that might be a good way of soldering it.