Duct Sizing!

[C_Henderson]

I know this isnt really a/c, but theres no section for ventilation or anything on here...

just wondering how you work out your duct sizing for a room.

i know how to work out the main duct, using
volume = XSA x velocity

but the further away the duct is and the more legs it has, the smaller it needs to be. how do you work out the reductions in the duct sizes?

[frank]

Draw a plan of each area/office. Work out the amount of air required in each area/office.

Now draw a line for the ductwork across your plan where you want the duct to run/join together etc.

Using the formula that you posted you can now size each branch duct from each room and note it down on the plan. Where a branch duct joins onto the main duct run, add each air volume together at that point and then formulate the duct size again for that duct section. Work your way out to the air intake/discharge point where you then should have a total air volume for the system.

[Toosh]

Hi try this always try google whre I found this, GOOGLE is a powerful tool

http://www.pipingnews.com/airduct.htm

Norm

[dogma]

Trane and york have cheap ductulators. They may even give you 1 4 free.