Quote:
Originally Posted by Gunter
During the national events this year in touring cars (sorry buggy boys) we found that sucking the air reduced the heat by between 5 and 10 deg more than blowing.
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this is where theory and practise differs.
Best place for a fan, for maximum efficiency is in "clean air" so putting it in a position where it needs to suck (behind the motor) instantly puts it at a disadvantage due to the lack of clean air.
On the flip side, how "clean" is the air in front of the motor (in a blowing location)?
No-one knows, not without a wind tunnel anyway. And it will differ depending on car type, motor/ESC location, holes in the body shell (either sealing, cut holes, ducts, whatever). Then you have to consider packaging it all in as well, where do you have room for the fan, above, behind, in front (underneath!)? The difference between getting it wrong and getting it right could make 5-10 degrees performance difference depending on what temps you have in the first place (ambient, motor and/or ESC).
My specific example is on my buggy, with an ESC fan, where sucking thro all those fins on the heatsink really doesn't do it any favours, whereas blowing on to the heatsink fins, and consequently sucking the air from the intake above the ESC gives cleaner air flow (there is that damn theory again.......!) into the fan (and a more efficient fan, and more cooling)
Who knew that work would come in useful for RC cars