Vented hood question, want opinions

Doing a kitchen remodel and installing a vented range hood. Don't currently have one and haven't had one for over 17 years, but even then it was one of the cheap models. Due to space limitations and ducting options, I'm can only put in a 30" under cabinet hood. I'm also limited based on the ducting, which is about 7 feet of 3.25 x 10 inch running through wall and transitions to 20 feet of 7" round under the house to outside. With bends and all, equivalent length of around 40-45 feet. I get different opinions from everyone I ask about duct limits, cfm, make up air, etc.

I've spoken with a guy the Furguson showroom who recommended the Vent-A-Hood 300cfm hood, but I've read mixed reviews about it's unique fan and "magic lung" grease trap. Kind of scared of it.

Guy at Lowes said 600cfm was not an issue with duct size and didn't have to worried about air replacement, so it didn't interfere with HVAC system. Is he right?

So right now I'm considering either a Sears Kenmore Elite 450cfm hood,Broan AP1/RP1 440cfm hood or Broan 64000 series 600 cfm hood

Yays? Nays? Opinions?

This is the slide in range...http://www.sears.com/kenmore-elite-30inch-slide-in-dual-fuel-range/p-02241103000P?prdNo=5

The duct run is closer to 45' "equivalent length" which takes into account for bends. Yeah, wish I could run it straight up or out the wall, but can't and can't fit larger duct in walls. It has a variable speed fan so I doubt I'll have it turned all the way up unless searing something. Do the baffle grease filters work at lower fan speeds (150-300cfm) or are they only effective wide open (600cfm)?

I'm not sure this is a "will work" vs. "won't work" situation, rather "will work" but I won't get a full 600 cfm air draw and it will be a little louder on high compared to a hood with a shorter duct length. Here's what Sear's says in their install guide for a 450 cfm hood...
"Kenmore range hoods are designed to perform efncientiy when attached to long runs of duct. As a point of reference, this hood will function at approximately 80% of its rated air flow when 75 equivalent feet of 7" round ductwork is attached. Use this chart to calculate the equivalent duct length of your system."
I can live with only getting 450 cfm and a little more noise due to the length of duct.

I don't know if they are available any more, but years ago, we had an EXTERIOR exhaust fan installed for our range hood. It certainly make it quieter. But that was a while ago. It was a NuTone with a squirrel cage instead of a propeller. I now have it as a "puller" and it is wired up so it works with or without my new range hood exhaust fan, which is quite noisy. When I don't need a full-force exhaust, I turn it on and you can barely hear it.

Rita

Remote In-Line: Fantech

I have this one - http://www.cavalierehoods.com/products/Cavaliere-SV218Z-Wall-Mounted-Range-Hood.html

Although it looks like it is designed to be an outside mount, I put the upper part inside the cabinets and all you see is the bottom part.

Works well and quiet.

If there is room in the cabinet above, the 900CFM will get the air out

I'm Russell, I'm not clear in what your unit does. Is the exhaust vented to outside of the house?

Charcoal filters usually vent the exhaust back into the kitchen. Maybe I'm misunderstanding you. I admit that I have not had the time to check out your link, so I might be way off base.

Rita

This is the picture of my exhaust hood -



It's listed under wall mounted range hood.

But instead of mounting it on the wall, I took the upper portion and put it inside the cabinet above the stove.



The exhaust is above the unit out of the roof.

For a conceptual look at 900 cfm (cubic feet per minute), 400 cfm is equal to one ton of air conditioning, so 900 cfm is equivalent to just over 2 tons of air conditioning which will cool a well built 1500 square foot house. So when you run that 900 cfm vent fan, open a door or window to keep from putting such a negative pressure in your home.