First, a warning -- I have never lived in a house that needed make-up air. Not even close. Double-pane glass makes little sense for us since all the heat goes around the sashes in our Victorian. My experience with MUA is related to commercial systems. What follows is an opinion about the kinds of things that would make me consider MUA. Unless you have a Code requirement for make-up air, you have a fireplace you use when cooking (I seem to remember that you are South Bay?), have a "naturally" vented gas appliance in "connected space" (no always-closed doors between the hood and the appliance), or have a "tight" house (recent, energy-efficient construction, most likely), I would skip MUA. Even if you do need MUA, the difference in the maximum hood flow probably wouldn't significantly influence the the cost of the MUA system, which I would think was primarily labor driven. If not significantly more expensive, and you can run at least an 8" duct (preferably a 10"), I'd go with 900 CFM for two reasons: * You have it when you need it -- guests over, and the kitchen fills with smoke... * A 900 CFM blower at 600 CFM may be noticeably quieter than a 600 CFM blower at 600 CFM The 24" will serve you well. Enjoy your new range!

I've never had a hood larger than my range. Right now I have a 48" hood over a 48" Wolf gas rangetop (8 burners with 16K BTUS each). We do all sorts of cooking, including searing meat and lots of stir fry. I don't have any problems or complaints. I couldn't afford the jump to get one wider than 48". Because we use the panini grill, waffle irons, etc. next to the rangetop, I might have liked one that covers more area, but I wouldn't have gotten one larger just for the stove...And as a matter of fact, the hood we have does a decent job for that cooking we do off to the side. Like I do, you'll have upper cabinets that help funnel fumes, etc into the hood...It might be different if there was nothing around the hood to help with the capture.

Good Morning annab6! Well, yes, our cooktop is 36" and our insert is 33" inches, and you're right, the wood hood itself is 42" wide and 25" deep to accommodate my gew-gaw wishes (the mouldings). I only remembered the 33" insert part! The wood portion of our hood, rather, the lower portion is built out more than is required by the insert so as to, again, accommodate my wishes. The bottom of the wood hood is 30" above the (standard height) countertop. I love it!!! Our upper cabinets are 47.5" high (we've nine foot ceilings) with considerable crown moulding above. Our microwave is 24" wide and it's an over-the-counter model (so there's no shelf underneath it -- it's screwed into the support above). As jayjay wrote, some people get hoods considerably wider than their cooktops: this was something we investigated because my husband really likes to cook, esp. over high-heat, e.g., lots of stir-fry. With the kind, smart and patient owner of the local mom-and-pop shop where we purchased the bulk of our appliances we decided it would be unnecessary and overkill. Ours is a high BTU cooktop but with the 900 cfm vent we just wouldn't need anything wider. And we like the storage we souldn't have if we'd had a wider hood!

Thank you all for posting the pictures -- it helps me visualize. The look definitely works for transitional or traditional cabinetry. I'm still trying to figure out if a modern look requires wider. Fouramblues, I asked my architect and GC a few times about whether our city has a MUA requirement. They both said they had never heard of one (and they both appear to be allergic to research). I tried researching myself online without any luck. We live in SoCal (no AC) and leave the kitchen window open most of the year for fresh air, so that is our MUA plan, lol. We also have a 50-year-old house that is not even close to air tight. Secondhalf, is that the Kobe RA-02-1? Are you satisfied with the finish? I was considering the 42" 1000 CFM version of that hood. I could only find 1 Kobe hood in a local store. It was a different model (pyramid with straight corner instead of beveled) and there was a visible seam all the way up the "corner" where the front panel overlapped the sides panel (i.e., the pyramid part was made with 3 pieces of metal instead of 1). Is that how your hood is constructed, or is the lower part seamless? Also, how much space do you have between your uppers and the hood? GreenDesigns, I thought I could offset size with higher CFMs. Would I be better off with a 42" 715 CFM hood? One hood in my budget that I find aesthetically pleasing (other than the mesh filters) is the Zephyr Venezia. I'm not sure I will ever use the grill on the range, as we grill outdoors year round. I only bought that model because it was a floor model at 35% off. If I had realized what venting my "bargain" range would cost, I would have skipped it. Now I wish I had bought induction, as it would have been cheaper to replace all my pots and pans if I could use a simple 600 CFM hood.