>>> would a recirculating hood such as a Broan cbd330 make much of a difference in grease and odors vs no hood at all?<<< >>>I also know what CO is and why I should care about it.<<< >>>Our house is old and far from airtight.Is my hunch that this recirculating hood won't do much good right? Would it mitigate eau de cabbage stew any better than cracking a few windows?<<< My initial reactions to using that Broan without venting to the outside are these: that your Broan may help a bit with some aerosolized cooking grease (although the hood design means that a lot will not be captured); that the Broan may serve as a surface for condensing vapor but will be otherwise ineffective in dealing with vaporous combustion byproducts and steam, much less the odor/stench of boiled cabbage; and that it will do nothing about CO which you should not need to worry about, anyway. For removing odors when boiling cabbage etc., you might have better luck with the windows, particularly if you can toss-in a box fan or window fan for those occasions. CO emissions from modern gas ranges should be barely detectable with sophisticated equipment -- far below hazard levels --- unless somebody has really screwed with your burner adjustments The combustion byproducts from the burners are rather more smoglike with the principal components being CO2 and NO2. The Dept. of Energy in conjunction with the EPA published a study on air quality in kitchens with "unvented" gas ranges and the effectiveness of realtively affordable venting a couple of years ago. The result was some overblown media attention. It also got some interesting commentary here which you can find at this link if you are interested: http://ths.gardenweb.com/discussions/2304651/ny-times-the-kitchen-as-a-pollution-hazard The idea of getting a convertible hood and later installing outside venting is not a bad one. I'm guessing that you are not currently venting because your stove currently sits on an interior wall and you all have been stumped on how to get outside venting without a full kitchen remodel to relocate the stove. Is that correct? That's a problem I had with my old-house kitchen and I discovered numbers of relatively easy ways to go up from a vent and run ducting over to the nearest exterior wall through a cabinet. This was easy for me because the interior wall behind my stove butted into an exterior wall and because I didn't mind the somewhat industrial look of the ducting. Might or might not be that easy for your old house-kitchen and the look might or might not work for you. Having said that, the 30" Broan cbd330 may not be the best choice. It seems to be a low-rise hood which does not project very far out from the wall, and it has a flat base rather than a canopy. As kas has often pointed out, an actual canopy gives better coverage and capture and can be a significant part of the effectiveness of a range hood. Even better when the hood extends a bit wider than the stove. (Better still when the hood also has enough depth to extend as far out as the front of the stove, too.) Basically, the flat base on the Broan means that the unit depends entirely on fan-power to collect vapors, grease, and etc., The Broan has relatively low fan capacity. (250 CFM?) You might want to consider taking that unit back and swapping it for something with a canopy and, if it will fit, something 36" wide. Again, that may or may not work in your kitchen. My old-house kitchen was such that I also had to resort to a low-rise hood with a flat bottom rather than a canopy. We work with the kitchens we have.

The comments about ten-power settings got me musing on the subject and about Amy's initial question about logarithmic power controls. Here's where that lead me. Nobody really has logarithmic power controls, but there can be power settings spaced to sort of approximate a logarithmic curve -- a number of settings at the low end with only a couple of additional points needed to define the steep side of the curve for really high heat. In theory, that can be done with a ten-step power curve and some folks do find 10 power settings fine for what and how they cook. Others do not. Is anybody else here old enough to remember the GE stoves and cooktops from 50's and 60's with ten mechanical pushbuttons for heat settings? Those pushbuttons were literally "digital" controls, meaning that you punched them with one of your digits. GE sold a lot of them for a couple of decades, so some people found them adequate. Some did not. For the current digital electronic ten-step controls, others here besides loonlakecamp have reported satisfaction with a ten step set-up. Others, like me, would find them inconvenient for my cooking with, say, my pressure cookers. With only ten heat level steps, I would have to be constantly switching settings to maintain the correct pressure. Power setting "1" might be too low, setting "2" might be too high. Switch to 1 for a while until the pressure drops a little too low, switch to 2 for a while until it gets a little too high, then back to 1, etc., etc. With in-between settings, I avoid that annoyance. You don't use pressure cookers? Then maybe having in-between steps won't matter to you. This is just one example of how cooking styles can differ and how more settings can matter to one cook and not to another. Much fuss is sometimes made about the supposedly infinite adjustablity of gas burners. As a practical matter, though, we mostly try to get the burner to the same relatively few settings. Searing is pretty much searing, isn't it? If you deep fat fry, how often would you care if if the oil were at 352° instead of 350°? But maybe somebody is working with sugar syrups where, say, it might matter if a syrup is at 325° and not 360° and then maybe it matters if the induction burner only has ten settings. That said, the subject of induction power settings and controls can be more complicated than just the number of settings. The need for finding "in-between" steps for induction cooking can reflect two different aspects of ways that manufacturers design induction burner controls. One consideration is the power cycling that all induction burners use for settings of less than full power. A technical term for this is "pulse width modulation. or "PWM." It is the same kind of thing a microwave does for low heat levels---momentary pulses of power that average out at a particular heat level. With most PICs as well as some brands of induction cooktops and ranges, the PWM is pretty crude. I've seen this somewhere described as firing up the burner for a second or two of omigosh hot and then switching totally off for three or four seconds. While these pulses average out at a certain heat level the timing can be problematic for, say, the srambled eggs that Amy mentioned at the outset. Combine that kind of "low frequency" PWM with the crude power controls found on many PICs, and you could have a reason that Amy would find herself wanting steps in-between power level "1" and "2" for scambling eggs. Some full size induction ranges and cooktops work this way. I noticed a lot of pulsing at the low heat settings on the Maytag induction range I saw demoed several years ago when I was stove shopping. From past threads on PWM, I gather than Whirlpool's induction ranges and cooktops (which include Maytag and Kitchenaid brands) have used crude PWM. For searching out past threads here on this subject try a search strings like "induction + pulsing + gardenweb" and "induction + cycling + gardenweb." A few of the expensive PICs (Cooktek, Garland, Vollrath) and many full size ranges and cooktops use much higher frequency PWM. Instead switching on and off for a second or more at time, the power switches on and off many times per second. The higher frequency of switching yields much finer power control that more closely approximates a steady heat level. The other design aspect that can lead to wanting "in-between" settings is in how the engineers program the electronic controllers to space the power settings on the appliance you are using --- that's the kind of logarithmic curve I thnk Amy may been thinking about when she posed her question in the original post. . For manufacturers, the least costly controls use simple linear spacing. Setting "1" would use the PWM to average 10% power, setting "2" would be 20%, etc. Even with a high quality PWM, though, 9 or 10 linear settings may be too crude, A thing most induction users discover pretty quickly is that they do most of their cooking in the low to medium range settings. The highest setting can be used for boiling. One or two medium high settings takes care of high heat applications like searing. There seem to be three strategies for induction manufacturers to address the crudeness. One is to add half-steps between the numbered power settings. The other is to program the stove's controllers to put more steps in the low to medium range and fewer in the high ranges. The third strategey combines the first two. Without using the particular induction stove or cooktop, it can be hard to find out whether the particular unit was designed to use one or the other or some combination of them. In my own somewhat limited experience, it seems that the GE induction appliances and Electrolux's Frigidaire/Kenmore ranges seemed to use a modified-half step approach with some concentration of steps but also using half steps for finer control. The Electrolux-branded models use a slightly different approach with quarter-steps at the lower power ends and fewer steps at the high end. Miele cooktops seem to use a similar kind of mix with the option of switching on more steps. I'm not sure how BSH (which includes Bosch) handles this except that their induction appliances manuals show that half-steps are available. The Samsung freeestanding induction ranges seemed to follow the GE model (19 half steps). The reports about Samsung's ten-step "Chef Collection" model seem to conflict, some seeming to say that stepping is linear, some hinting that the settings may be skewed to the lower end. There is a yet another strategy which is the near infinite stepping of of potentiometer-like controls. These control systems seem to be very expensive so, AFAIK, they are used only for the commercial Garland/Manitowiac PICS and maybe the new Miele induction range have this. I say "maybe" for the Miele because there is nothing about it in the product literature and the display shows only whole-number settings, but a couple of posters here -- livinginseattle is the name I recall -- have reported finding that the knobs can be turned to provide fine gradations of "in-between" settings. Some folks would find that ideal. Then the question becomes: how much are you willing to spend for the "ideal" (and are there other design compromises that have to accept in order to get that ideal function for the burners?)

If you have not seen them, this thread and this one have discussions of the Bosch Benchmark slide-in by actual users. The GE induction ranges have been among the most popular with users here at gardenweb., so there are lots of threads discussing them. The components of the GE Profile PHS920 are very similar to those of the freestanding version, the PHS920. The main difference is that the front control panel on the slide-in reduces the usable cooktop space by a couple of inches. Otherwise, you can check out reviews for both. The induction set-up is very similar to the predecessor models, the PHS925 and PHB925, so reviews of those also may be helpful. (The main difference that I can see is that the "920" models let you link the controls for the two 8" burners on the left where the "925" models did not have linking.) The "920" models have been out for three years and something now, so most of the discussions are a little older. Here's a thread in case you have not seen it. The search strings "gardenweb + GE induction range" and "gardenweb + PHS920" turned up a lot more threads here plus some from Chowhound, too. The latest versions of the PHS/PHB920 are supposed to have the smartphone connections and controllability, but I have not seen any reports yet on how it works or does not work. The Frigidaire induction slide-in is far and away the least expensive induction slide-in (about $1400 "in the cart" at AJ Madison, for example). However, there has been very little comment on it here from actual users. As with other Frigidaire electric-slide-in ranges, the oven vents to the front of the stove. You could research those models to find comments and opinions about that featue.

I think it is a valid statement that a chimney hood is closer to ideal for capture and containment than most microwave oven venting schemes. If you search for KVSApplDesign_catalog.pdf, a publication by Greenheck, and read it or even skim it, you will learn what is considered important for ventilating commercial cooking. From this base it is possible to "eyeball" residential devices and estimate how far they deviate from ideal and hence surmise whether or not they are the best solution for the space. It is important to keep in mind that you can have only two out of three among performance, affordability, and aesthetics. With respect to the association of "equal blower capacity" and the fact that two blowers are rated at equal CFM, I have to point out that neither blower will be operating in free air, so each has some pressure drop across it. For the blowers to be equal, their fan curves (flow vs. pressure drop) have to be equal. This is unlikely. Further, the microwave may be expected to have a more tortuous path for the air flow, causing it be operate farther to the left (lower flow rate, higher pressure drop) on its fan curve. This would be expected to further reduce its flow rate over that of the more conventional hood. Your candidate 30 x 22-inch hood is (ignoring wall thicknesses that I don't know) 4.6 square feet in nominal aperture area. The actual desired flow would be 4.6 x 90 ~ 400 CFM. With a leaky house but no deliberate MUA you would want a blower rated for at least 600 CFM. We can cut that down somewhat by arguing that induction has a lower plume velocity, and the type of cooking is less extravagant. From page 9 of the Greenheck document take the velocity requirement to be 50 ft/min instead of 90, and this yields 230 CFM actual. A 400 CFM rated blower with leakage MUA may work for this. However, 22 inches is not much frontal overlap, nor is a 30-inch wide hood much overlap for pans that may extend to the edges of a 30-inch induction cooktop. So, while what has been captured may be fully contained, unless your greasy cooking is done at the back, and a cabinet side partly blocks the cooking plume expansion toward the side of the hood, some odor and grease may be expected to still be present in the room. For a higher level of capture, a 36 x 27 inch hood would be preferred. This would, however, require deliberate MUA, depending on how your code requirement is worded, what combustion appliances you have and their sources of MUA, and whether your AHJ understands what safety issues MUA is intended to avoid. kas