CFM ratings

[65coronet440]

I am swapping to a electric fan, i removed a 18" original mechanical fan and wanted to know the CFM rating it had so i can purchase a electric with compatible CFM

Thanks

Its a 1965 Coronet with the 440RB

 

[lewtot184]

mechanical fans don't have cfm ratings. they'll vary air flow as the rpm varies. electrics can have a cfm rating because they operate at a constant speed.