Going to have to install range hood with outside exhaust (through the roof) this weekend... I'm having new roof installed and want this in prior to new roof so I'm pushed for time.. My current hood is just a "blow steam and grease in the top of your head while cooking type...
My length of ducting is well below the max for either.. 7ft of 7" round duct with no turns. Possibly needing a rectangular to round adapter depending on model of hood It's a 30" hood.. I see some with 220 cfm and 390 cfm for twice the money.. Is the 390 cfm needed? $380. for the 390 cfm $130 for the 220 cfm I wouldn't mind the 390 cfm as much if it's strong enough to pull in fresh air if something get's "funky" smelling.. and I open a couple windows.. though I know it's not a whole house fan... Thanks.. Chuck (in SC)