Correct duct size

Servicewiz_3

I am currently working on a job that appears to have the supplt & return ducts chocked down considering the size of the unit.Can I get the name of a good website or a rule of thumb when it comes to CFM & suitable duct size.thanks in advance for the help!!!!!!!!

meplumber

Ductulator

Get yourself a good Ductulator. I have been designing duct with mine for years.

Techman

Ductulator's

Also track down a  flex duct Ductulator for flex duct.

TonyS

Duct sizing workbook

This is a handy notebook

Techman

Duct sizing

Hi TonyS. I like that HandBook way of looking at ducting,thanks .There is a lot of 8" high supply trunks in residential. But, on the return duct sizing we try for .08"w.c. depending or .06"w.c. depending. Our returns are larger than our supplies.

TonyS

Your welcome Techman

I use that book when I am coming out of boiler mode. I find as I get older I still have a good memory except its alot shorter LOL

Techman

TonyS

I just looked at your photo in the "contact user" section . I have two questions , one personal and one business. Business first , Is she your helper ? Now personel , Where do you keep the pipe wrenches? LOL ,with you I hope!!!!!!!!!!!!

meplumber

Thanks Tony.

That is a mighty handy cheat sheet. I feel your pain. Things don't come out of the old Noggin' as fast as they used to.