Fan opacity

DrMrLordX

Lifer
Apr 27, 2000
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Is it possible to set up a fan to be mostly opaque during operation (ideally scattering light reaching the fan, at least from one direction if not both)? Or is this possible with multiple fans in series with their fins facing in opposite directions spinning in opposite directions?
 

CycloWizard

Lifer
Sep 10, 2001
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It is possible, but would be extremely complicated. One fan will never appear opaque unless the turbine blades overlap completely (which is possible, though I don't recall ever seeing such a design, since it would be very inefficient). If you have fans spinning in opposite directions, the cooling will be very poor. Fans spinning in the same direction would be a little better, but you'd probably be better off finding a single fan that has overlapping blades as this would almost certainly have a higher efficiency.

Maybe if you described a little more about what you're trying to achieve I could give a little more helpful advice.
 

DrMrLordX

Lifer
Apr 27, 2000
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Originally posted by: CycloWizard


Maybe if you described a little more about what you're trying to achieve I could give a little more helpful advice.

What I am primarily interested in doing is finding a way to remove hot air from inside an enclosure without allowing light the ability to escape in any significant amount (assume there is a lightsource insidet he enclosure).
 

Mark R

Diamond Member
Oct 9, 1999
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The way we used to do this in darkrooms was to put a mushroom shaped dome over the fan, with the inside of the dome painted black.

Air gets blown through the stalk, when it fans out under the dome and escapes from vents on the underside of the dome.
 

CycloWizard

Lifer
Sep 10, 2001
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Originally posted by: Mark R
The way we used to do this in darkrooms was to put a mushroom shaped dome over the fan, with the inside of the dome painted black.

Air gets blown through the stalk, when it fans out under the dome and escapes from vents on the underside of the dome.
Yeah, I believe this is called a fan shroud.
 

Markbnj

Elite Member <br>Moderator Emeritus
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Sep 16, 2005
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Originally posted by: CycloWizard
Originally posted by: Mark R
The way we used to do this in darkrooms was to put a mushroom shaped dome over the fan, with the inside of the dome painted black.

Air gets blown through the stalk, when it fans out under the dome and escapes from vents on the underside of the dome.
Yeah, I believe this is called a fan shroud.

You'd think there would be some angle or eye-height that would allow you to see through those lower vents and through the fan. How about a no-moving-parts solution: baffled intake at the bottom, and a baffled exhaust at the top; let the hot air flow out and pull cool air in at the bottom? Another easy one is just to use some ducting or pipe to get the fan and exhaust well away from the light box.
 

CycloWizard

Lifer
Sep 10, 2001
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Originally posted by: Markbnj
You'd think there would be some angle or eye-height that would allow you to see through those lower vents and through the fan. How about a no-moving-parts solution: baffled intake at the bottom, and a baffled exhaust at the top; let the hot air flow out and pull cool air in at the bottom? Another easy one is just to use some ducting or pipe to get the fan and exhaust well away from the light box.
Well, I think the simplest solution is to simply remove the light source. But what fun is that? :p
 

Markbnj

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When I was about 20 (several presidents ago), I tried building something like this for certain horticultural experiments. Never was able to get the temp and humidity right.
 

Throckmorton

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Aug 23, 2007
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Originally posted by: Markbnj
When I was about 20 (several presidents ago), I tried building something like this for certain horticultural experiments. Never was able to get the temp and humidity right.

Horticultural experiments? Trying to hide your grow lights from 5-0?
 

Markbnj

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Originally posted by: Throckmorton
Originally posted by: Markbnj
When I was about 20 (several presidents ago), I tried building something like this for certain horticultural experiments. Never was able to get the temp and humidity right.

Horticultural experiments? Trying to hide your grow lights from 5-0?

5-0? What's that, like Hawaii 5-0? I wish. More like Indiana 0-0.