Some good points there which I shall definitely bear in mind. The fan motor can be chucked out and replaced with a standard fan module AFAIK with some minor rework.
Why can't a standard fan(12v or whatever) be fitted and just simply connected direct to a suitable supply rail, yes the fan would on all the time, but is that necessarily a bad thing? ![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
That's a good question, and the answer is complex; but mostly it boils down to the nature of MOST axial fans: they are NOT meant to serve as a positive displacement air mover; they are meant as an air circulation device against zero head pressure/static load.
If you are trying to blow against a static load like a radiator or heavy grill, or in the case of a 2465, you are trying to pull a partial vacuum inside a sealed case so that air is drawn across specific components via strategically located air vents, then it matters VERY MUCH what kind of fan you use.
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif)
There ARE axial fans which are designed to move positive pressure against a static load; they have more powerful motors and a different airfoil shape and more aggressive pitch to the blades, and tend to be a lot noisier than their non-static-load-rated cousins. This is why Tek chose a
centrifugal fan/squirrelcage fan instead of an
axial/muffin fan.
However, it appears their solution was met with both reliability issues and customer complaint, so in later versions they did in fact revise to use a noisier static-load rated axial blower.
Myself, if I were replacing the fan due to complete failure, I'd look for a centrifugal blower of approximately the same size wheel and current draw and remove the outer shell so I could install it in the back cover. Or possibly a Noctua axial blower rated for static load, though it might be hard to find one small enough AND reasonably quiet.
Cheers,
mnem
Yes, I have spent entirely too much time thinking about this. Thank you for noticing.
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif)