reluctantartist - Here's the issue, as I understand it. This is NOT a formal legal opinion, so don't rely on it, but... Calforna's standards for residential construction are contained in the California Residential Code, which is part of Title 24 of the California Code of Regulations (CCR). As of January 2011, for the first time, the CRC does follow the 2009 IRC. It doesn't just do it by reference, however, it adopts specific code sections that contain the language of the model code, sometimes in slightly modified form. More importantly, the California Residential Code ONLY adopts equivalents of the IRC codes up through the end of Part III (("Building Planning and Construction") of the 2009 IRC. The section of the IRC that addresses makeup air (section 1503.4), however, is in Part 5 of the 2009 IRC ("Mechanical"), within Chapter 15 ("Exhaust Systems"). If you look at the California Residential Code, however, it specifically says "Note: Part V is not adopted. See California Mechanical Code, Title 24, Part 4") This is actually part of the California Residential Code as posted on ICC's own site, as shown in the attached link. The 2010 California Mechanical Code, is based not on the equivalent sections of the IRC, but on the Uniform Mechanical Code. I does NOT contain any makeup air requirement(s) equivalent to section 1503.4 of the IRC. It does contain provisions for makeup air of gas heaters, commercial kitchens, etc, but the ONLY potentially directly relevant section of the CMC to residential ventilation, based on my cursory initial review, is Section 701.1.4, which states the general proposition that "Where exhaust fans, clothes dryers and kitchen ventilation systems interfere with the operation of appliances, makeup air shall be provided." No specific standards for CFM. The other section of the CMC for residential ranges is section 504 (Environmental Air Ducts) and its subsections, which doesn't address makeup air but does say generally that "Environmental air ducts not regulated by other provisions of this code shall comply with this section . . . Exhaust ducts shall terminate outside the building and shall be equipped with back-draft dampers...Environmental air duct exhaust shall terminate a minimum of three (3) feet (914 mm) from property line and three (3) feet (914 mm) from openings into the building." It also says, more specifically at subsection 504.2 ("Domestic Range Vents") that "Ducts used for domestic kitchen range ventilation shall be of metal and shall have smooth interior surfaces." I can't find the reference right now, but I remember there is also a provision stating that kitchen exhausts can't issue into "walkways." Again, this isn't a legal opinion, and I could be wrong. Also, in California as everywhere else local jurisdictions are free to adopt MORE stringent code requirements, so you still need to check with your local agency to make sure they haven't independently adopted a specific makeup air requirement. But in the absence of such a local requirement, I don't think there is any hard and fast CFM-related makeup air requirement in California, at least yet.

Did the previous owners get away with not having MUA? Might be because they installed the commercial stuff a long time ago and nobody asked about MUA. If the house is big enough and old enough, it might have been "leaky" enough that an MUA system was not needed. Or, the previous owners may very well have installed a make-up air system and it may have been the kind that was integrated with the commercial hood. The realtor should know or be able to find out from the previous owners. If that does not work, then you'll have to go looking for it because there are numbers of different kinds of MUA systems for commercial hoods. Some can even be part of the hood system. If you are interested, here's a resource that illustrates and discusses different kinds of commercial MUA systems which may give you some hints of where to look for MUA in your newly acquired kitchen. . http://www.fishnick.com/ventilation/designguides/CKV_Design_Guide_2_031504.pdf Also, check out Kaseki's clippings page. As for who you need for building/designing/installing an MUA system, there is no simple answer because it is not a one-size-fits-all or one-stop-shop kind of thing. The short answer to any MUA question will always be "it depends." If you live in a warm climate, MUA might be as simple as opening a window when you run the hood above 400 cfm. Or you might be able use a "MUA damper." There's a current thread on these. Here's the link: http://ths.gardenweb.com/forums/load/appl/msg0313214523464.html If you live in the great northland of cold winters (say, Minnesota) or in a place where air-conditioning is the norm for months (say, Phoenix), the MUA thing may involve air exchangers which gets a lot more complicated and expensive. About all I can suggest is that you look at the many postings about MUA over the last couple of years. A search using "kaseki + mua" should get you a lot of threads to look at. This post was edited by JWVideo on Sun, Mar 24, 13 at 1:54

Thank you, thank you for all the wonderful feedback. I do want to stick with getting the grill and am going to do so. We probably will be cooking steaks outside most of the year (Jersey Shore), but in the dead of winter (especially like the last one) we would be cooking inside for 3 months or so. I want to grill vegetables, romaine, etc. inside. Two of you mention that you have the Wolf hood. Did you entertain the Best one? I have not priced the Wolf, but based on your comments will look into it. I had thought of Modernaire, Best and now Wolf. I do think I want to go a bit higher than the 1200cfm just because we have had such problems with setting off alarms. I will definitely try seeing how a 27" looks/feels - my hubby is 6'1" and because of his height we have had to scrap buying cute little converible :( so want to make sure he is okay with the height of the hoodt - he is the steak pro at our house! JScout - where do I look up more info regarding make up air. Would it only go on when the fan was on? Where should it be installed, how much, etc.... We keep finding and adding things in $$$$$! But, this is our dream house and we are so looking to doing it the way we want. Again, to all of you who took the time to write in - THANK YOU! Pls let me know any more thought on the air thing and if the brand of the hood makes a difference. Will certainly post once we are in. Ordering cabinets and they are beautiful. Now in the midst of all the appliances .

Its possible that an environmental air company could help here. While typical recirculating hoods only partially remove the grease and odor, thereby justifying this forum's general distaste for them, it is possible to build a filter system that might be adequate. Important factors would be having enough space above the stove or across the ceiling, rigorous scheduled cleaning of all metal filters, and scheduled replacement of fiber, lint, and charcoal filters. One of the problems with recirculating hoods is that charcoal reduces odor by adsorbing odor molecules into the carbon matrix. Grease will quickly cover the grains and stop this process. Hence, excellent grease filtering is needed before the charcoal filters. By excellent, I mean that filters optimized for the entire spectrum of grease particle sizes are needed. Baffles only do the larger particles, and act as a fire stop. Meshes and ball bearing style filters can further address another part of the spectrum, followed by fiber filters and lint style filters capturing the fine particulates. Then the charcoal filters can work on the odor for long enough to be cost effective. There may be a place in this stack for a UV system to break down grease particles, with the charcoal burdened with ozone filtration. A filter system of this type should be designed by a qualified HVAC company, and requires the aforementioned space in the room and adequate funding. The pressure loss through the system may be high, so a blower sized to the pressure loss is needed. One does save on make-up air system costs, however. kas