figuring cfm

[John Burton]

is there a formula to figure the cfm of a squirrel cage blower the one that came with my 2x6 was homemade and I am currious as to its output. the motor is a dayton4c723 1/45hp rpm/tr/min 2300 cage is2 in wide by 4 in dia

[RileySugarbush]

Look in the Grainger catalog for a shaded pole motor blower that has the same dimensions and rpm as yours and you will probably be close. I'm guessing that blower will be about 150 CFM open and about 80 CFM with 1" of static pressure, so somewhere in that range. Does it work well? I just put a little bigger one on my new 2x6 and will fire it up for the first time tomorrow.