Re: [ATM] A coolingfan under a 12,5 inch

["Arjan te Marvelde" <arjan.te.marvelde@hetnet.nl>]

Harro,

> Question 1: my fan will be placed only 1 inch under the mirror. Doesn't
this
> fan create a local cold spot on the mirror, thus creating deformation?
>
> Question 2: should the fan blow air up? Or should it pull the air down (In
> my eyes, this should not create a cold spot)?
>
> Question 3: my coolingfan is a small one (only 2 inches wide) so it won't
> consume too much power. I understood from the articles in Sky&Telescope
> (July 2004?) that even the smallest fan can do a good job. What do you
> think?

At least you should mount the fan on a plate with a hole in it, so that you
don't short-circuit the air ciculation but direct it along the mirror
surface. Closer proximity to the mirror will increase the air velocity and
make the cooling more efficient. I don't think sucking or blowing makes much
difference, although theoretically sucking would mean temp difference is
highest where the airflow is slowest.

/Arjan

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