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Slow running fans

Discussion in 'Home Cinema Building DIY' started by nathan_silly, Jun 6, 2003.

  1. nathan_silly

    nathan_silly
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    My amp runs quite hot- just adding a desk fan has reduced it from hot to the touch to barely warm!:eek: so I'm wondering how can I build slow running & silent fans above the two ventilation holes to allow for cooling?

    Even something like 50rpm should do- or maybe with a pot to adjust the speed.

    Ideally I would like 240V fans- I'll just wire them upto my 4 way plug.

    Thanks
     
  2. buns

    buns
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    Im looking for mains fans for my new pj hush box....... though im getting the feeling the noise will be rather hit or miss.

    Do you have any idea what noise figures relate to...... i see maplins 80mm at 33dbA.... though i must admit i dont know what A has to do with it.......

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  3. nathan_silly

    nathan_silly
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    A weighting.

    I only need them to move a little bit of air, I reckon even 25mm fans will do. Better than just still air.
     
  4. cradleoffilth

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    wouldn't fans emmit rfi or emf?
     
  5. nathan_silly

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    hmm if you're right I could just use 12v fans instead.

    I've heard that 240V fans are audibly quieter though (either brush noise or wind noise) Is this correct?
     
  6. buns

    buns
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    i have had a good look there and i cant find any fans the like of which you are talking...... they are all much much faster.

    Is 30 dbA quiet or loud?!

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  7. Jeff

    Jeff
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    For a projector its quiet, but its still a fair amount of noise.
     
  8. cradleoffilth

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    have a look on quietpc.comthey have fans which are about 18db
     
  9. buns

    buns
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    ok..... but considering a 0.75 inch mdf enclosure with a loudish projector in it and the fan mounted in the top...... i presume there is every chance that the projector fan will dominate?

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  10. Big Adam

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    Kustom PCs Fans

    Ignore the ones with fancy LEDs. You want the Papst silent fans.

    These are the dogs danglies for silent PCs. Would do your projects a treat. The 12dba 80mm model is highly recommended.

    Big A :p
     
  11. buns

    buns
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    The difficulty with all these silent pc affairs is they are not 240V so require additional tranformers......

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  12. clockwork

    clockwork
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    You can get 12db &19db 80mm papst fans which are next to silent! I use them in my PC. Well worth a look!

    Try www.overclockers.co.uk

    I just took a look at the KustomPCs link.... They have the same fans there :)
     
  13. BK Electronics

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    You can slow a 240V fan down by wiring a capacitor in series with the lead. You would need to experiment to get the right capacitor value, but a good starting point would be 400V 470n
     
  14. nathan_silly

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    Thanx for the info everybody. I've set the left/rights to small 80hz and the amps get warm now (were set to large, probably reason getting toasty)

    Sounds better anyway, room is a bit small- setting to large is a bit boomy- so can tailer the low end with the subwoofer.
     

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