Is your hood connected to exterior venting or is it a recirculating system?

recirculating.

No other hood manufacturer is in their league. Check out Vent-a-Hood.

We researched this thoroughly and will be installing a Vent-a-hood. We are installing a new Wolf range with grill and needed power, oversize and quiet. I believe this is the best!

The ship has probably already sailed, but do not bother with a recirculating hood over a high performance range. Figure out how to duct it out or you will regret it when you use your grill.

We have a 6-burner Viking and would not consider using it without the hood - our smoke alarm would be going off every day!

If you want it to be quiet, get an external fan instead of an internal one. No less than 600 cfm; 1000 cfm would be better.

You probably don't need to go this far (2500 cfm):

Although other range hood manufacturers often copy their style , for functionality that actually works, nobody - but nobody - does range hoods better than Vent-A-Hood. I've recommended and used them many times in new construction and renovation jobs. Yes, a little more expensive than their competition - those that are no more than a "decorative" range hood, there really is no comparison with Vent-A-Hood.. Vent-a-Hood is in a class of their own. And yes, if possible, vent it outside.
http://www.ventahood.com/

If your range is gas fired, I wouldn't ever use a recirculating fan, it is dangerous with the products of combustion not being vented outdoors.

In some areas, code requires it be 30" from the cooktop and vented to the outside.

thanks for all of your comments!