Question on fans

[nosaj]

What should proper orientation of a fan be in a powered mixer? Blowing in or pulling out?

Got a chinese one here that blows in, my thoughts are it should blow out sucking air from vents in the front of mixer pulling it out the rear.

It has been over heating BTW I changed it to how I thought it should be and am running it for the weekend.

Thanks,
nosaj

[Chuck H]

I think it depends on ALL the orientations. I'm usually a blowing out/suck fresh air through the vents guy. It just makes sense to me because:

1) Vents can be filtered while putting a filter of some kind right on the fan would detriment efficiency more and complicate spacing. So if filters are exclusive to vents then it would seem better to draw filtered air in rather than blow in dusty air.?.

2) It seems more about the introduction of fresh, cool air rather than blowing the majority of the cool air directly onto an isolated area. That is, there's usually more even flow distribution through vents. which are typically more spacious and in several locations. If you have a bank of transistors on heat sinks and the fan is blowing across the bank then it's doing most of it's good on the nearest transistor. In this case even air flow seems better than a one sided blast.

There may be exceptions. Maybe a fan is located such that it hits the heat sinks on the only two power devices in an amp. In which case the fan is likely intended to blow rather than suck. I think you just have to look at the overall layout and make your best guess about the designers intentions sometimes.

[minim]

You're both right, and it's due to air pressure. Blowing air in just pressurizes the space, resulting in limited air flow. Trust me, we spent more time than we should've trying to cool down a perforated air box (within a coldroom) with a fan pointing in from the coldroom, wondering why the bastard wasn't getting cold. We turned the fan around so it sucked the air in to the box, as opposed to forcing it in, and the box cooled down within 3-4 mins. You're welcome. See you in another year.

[Chuck H]

You're both right, and it's due to air pressure. Blowing air in just pressurizes the space, resulting in limited air flow. Trust me, we spent more time than we should've trying to cool down a perforated air box (within a coldroom) with a fan pointing in from the coldroom, wondering why the bastard wasn't getting cold. We turned the fan around so it sucked the air in to the box, as opposed to forcing it in, and the box cooled down within 3-4 mins. You're welcome. See you in another year.

Nice to see you. Thanks for the related experience. And don't be a stranger.