Hi, I am installing a ceiling mount ventilator and need to compare what the static pressure is for 10" and 8" duct run. The duct line consists of two 90's and 15 ft. of straight non-flex duct.
Use your ductulator.
Static pressure would be relative to the cfms required .
at .1 8in is about 250cfm and 10in is about 375 cfm
this is off the top of my head with out a ductulator but should serve your needs