Thread: duct sizing

don't come out to 100mm from 75mm. the loss and turbulance is too great. run it in the box (trunking) that way you'll still beable to access it with out pulling the walls down if you need to at a later stage.

Originally Posted by coffenup

hi ya fella & ladies
I was just wondering as i'm about to start lining & insulating the inside of my shed & I am also thinking of putting ducting for the dust extractor in behind the walls. As I don't like the way the work shops look with the ducting exposed around the walls.

Well it's going to be a right PITA and look worse when you have a blockage and have to rip it all apart to fix that or you want to change it.

So I have only 75mm gaps inside the walls would this work with a 2 hp unit with out colapsing I will expand out to 100 mm flexi pipes with waste gates by the wall. I have decided where most of my main machinery will sit as I already have most of it. I will allow for a few extra outlets fo the future additions of equipment and also a sweeping shoot.

75 mm is too small, while it's only 25% smaller in radius but 78% smaller in area which makes a BIG difference.

[/QUOTE] Or the other option is to run it around the top of the wall enclosed in a box to hide it and keep the dust down.[/QUOTE]
That's a much better idea than fully enclosed - especially if you use tek screwed panels as covers.