Better use an aspirating ventilator to cool a processor
This is the common layout of a heatsink and a ventilator above a
processor to blow its heat away. The processor is drawn green, the
heatsink is grey and the ventilator is black:
In every PC I opened till now, the ventilator blows towards
the heatsink. This layout has several disadvantages:
Dust accumulates between the ventilator and the heatsink. To
clean the dust you have to unscrew the ventilator. I saw two PCs were
the dust accumulated up to the point that the path of
the air was completely closed.
The ventilator is very noisy. Silent ventilators exist, or
ventilators triggered by a temperature probe. Such ventilators are
expensive and not always reliable. Two friends got problems.
When some ventilators get old they start vibrating. The
vibration makes even more noise and I suppose it isn't good for the
processor and the motherboard.
The blades of the heatsink decrease the surface the air can blow
through. The circular section of the ventilator reduces the surface
too. The resulting open surface of the heatsink and the ventilator
superposed is even less.
So, I inverted all this. I made the ventilator to aspirate the air from
the heatsink instead of blowing towards the heatsink and I fixated the
ventilator an inch above the heatsink using duct tape:
I used about 4 layers of duct tape to get a reasonably rigid structure,
then I forced the ventilator down about a centimeter to crunch the duct
tape. That way the duct tape forms a supply link between the ventilator
and the heatsink.
The result is excellent: the processor is a little cooler, the
ventilator is much quiter and its noise is far less disturbing. I
expect the dust will be much easier to clean since I'll just have to
vacuum clean the sides of the heatsink.
This photo shows my first attempt, on an AMD Athlon processor. The
white nylon bolts date from another hack. Note the little ventilator at
the bottom of the picture, aimed at the motherboard main chip:
This photo shows the same on a Pentium 4 Celeron processor. The
ventilator is a big one from a power supply. Powered at 12 V it keeps
the heatsink cold even under heavy processor calculations. Powered at 7
V it keeps the heatsink at low temperature and makes virtually no
noise. Don't be impressed by the distance bewteen the heatsink and the
ventilator: there is a native huge plastic structure above the heatsink
and I strapped the tape around it.
For industrial manufacture I suppose a supple polymer link between the
heatsink and the ventilator would do the job.
