VAH cfm explanation is bogus. If it is rate at 300 cfm it's not the equivqlent of some other vendors 600 cfm. The Prestie can rear duct at 1200 cfm and has stainless baffle filters for ease of cleaning. VAH has a grease trunk and is a horrible clean up. If there system is what they say how come all commercial settings are with baffles and not magic lungs (spit toons)

"If it is rate at 300 cfm it's not the equivqlent of some other vendors 600 cfm."

Right. It's the equivalent of some other vendors 450 cfm. Supposedly.

If it's true that other manufacturers rate their CFM without baffles, mesh, etc. in place, then VAH's claim seems entirely plausible.

OTOH if your range calls for 900 CFM and you call VAH and ask if you should go with 900 or 600, they'll tell you to go with the mfr's requirement - 900. And good luck getting an explanation; they just talk in circles until you give up. At least that's been my experience.

More on topic though - I'd check codes about venting into that porch. Somehow that just doesn't sound good to me. And I have the same exact situation - going into the screened in porch would be my easiest solution.

As for cleaning the VAH, unfortunately people seem split down the middle here as to whether it's easy or hard. That makes it difficult to form your own opinion without actually trying it yourself.

I would never vent into a porch and seriously doubt that would pass code. The requirement is to duct the exhaust to the OUTSIDE, and a screened porch is living space to me. Do you really want the impurities of combustion in the porch area? I wouldn't. It's not a question of what you might or might not do, it's a question of safety, and frankly, common sense.

I may be wrong since I've only looked at island hoods, but I'm not aware of any VAH that would exhaust horizontally through a wall. The larger ones, which you would certainly need for a 48" range all combine two 8 inch ducts into one 12 inch duct and they go straight up.

We just went through this exercise and are installing new 10 inch ducting up through the 2nd floor and out the roof to a rooftop blower. Will also be installing a Fantech silencer in the attic. Even with all these precautions I don't expect it to be silent (you are moving a lot of air across the baffles), but it should be very tollerable.

We have the 48" bluestar with grill and griddle and we went with a 48" prestige with 1200 cfm. We put in the remote blower - frankly it's a lot less noisy than I expected. We can easily talk with it on. In fact, sometimes I forget it's on! It does a great job clearing out smoke and capturing grease. BTW, ours vents out up through the roof.

fenworth it has been my experience also that when talking to vent-a-hood I feel like I called somebodys political office and get more non answers than answers