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Topic Title: Condensation in ducting
Topic Summary: Solid duct?
Created On: 15 January 2013 07:14 PM
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 15 January 2013 07:14 PM
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Evening everyone

I have looked at a job tonight where the customer gets water in the flexi ducting in his inline fan.

Has anybody come up with a good solution to this problem?

I have read that 4" solid pipe might be the answer? Or a drain away kit? Insulation?

It is a bout a 6m length in total.

Need to give a quote by Wednesday night.

Thanks in advance

 15 January 2013 07:20 PM
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both a drain point and insulation would help - either would do the job, both is better - easier to do with rigid ducting - basically the warm, moist air being extracted is cooling within the duct in the attic void and condensation is inevitable.

Over 6m, quite a lot of heat transfer is taking place so rigid duct is almost essential.



Let the wind blow you, across a big floor.
 15 January 2013 07:39 PM
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easiest way is to tie the ducting up as high as possible so it runs straight up from the fan and then slops down to the vent with out any bends. that way any condensation will either run back down through the fan and drip out into the room or run down the ducting and out of the vent grill )) or you could do the Bob The Builder trick and just remove the ducting

Flexi ducting is great for short runs but a nice lump of solid ducting is always better
 15 January 2013 09:19 PM
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 15 January 2013 10:10 PM
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That's the stuff as in the link above, insulated ducting. The insulated ducting should sort out the problem, but keep the duct run as short as possible. Also at 6 metres an axial fan is no good, use a centrifugal fan. If you have a longer vertical run you may need a condensation trap with an overflow run-off. Solid ducting gives less drag but on 6 m I wouldn't think this would be too important.

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