Someone here ( I can't remember the right search words to find the thread) did a formula of how many CFMs you need based on the BTUs of the range.

Although I would doubt you are doing any cooking that needs 1200 cfm. At that point you definitely need some sort of make up air system.

If you have it down to two, I would start looking at features—auto on, two level lighting, _noise level (measured in sones)_, etc.

I will say 7 sones is a whole lot louder than I thought they would be. But I rarely use my rangehood at full blast anyway (and then it is usually to help ventilate a "mistake").

And if this is a new install, make sure the duct size matches what you are putting in. I have a 6" duct, so unless I wanted to to rip out my ceiling and roof and start from scratch that's what I have to deal with. (Larger diameter duct also helps with noise level).

Just some thoughts,

Joe

Just starting this search myself. I am looking at the 36" Fulgor Milano Sofia DF range. They have an offer now that includes a range hood. Did you consider the Fulgor hood. As well,how do you like your stove.

lynne

Actual air flow rate for hot residential cooking (such as wokking) should be around 90 CFM per square foot of hood entrance aperture. (Total realized flow rate, then, is the product of 90 and the area in sq. ft.) To achieve this with a real blower requires the blower be rated higher than this multiplication product. Use a factor of 1.5X unless you do the math related to pressure loss in baffles, hood transitions, ducts, and the make-up air path (which are all a function of the air flow rate).

Note that the rising plume velocity has been measured to be somewhat lower for induction cooktops than gas cooktops due to induction cooking plumes lacking entrained hot combustion byproducts. For induction, an argument can be made that the air flow can be lower. However, I achieve about 90 ft/min at full power over my induction wok, and wouldn't go lower without an even larger hood.

The factor of 1.5X tries to account for typical blower fan curves (loss of flow rate with pressure across the fan) and the losses listed above. However, not all blowers are equal and they will have different fan curves. Hoods are not equal, and they will have different pressure loss functions. MUA options are so varied that pressure loss vs. approach will be all over the place. (You have planned your MUA approach, I presume.)

The old rule of thumb of Y CFM per Z BTU/hr came from commercial systems that generally have very similar high-flow, large-aperture hoods. It is a derived rule and not directly related to the actual physical requirement of avoiding meter per second rising plume reflection from hood interior metal and baffles that would allow the effluent to escape the hood. Principles of capture and containment, along with rules of thumb, may be reviewed in Greenheck's Kitchen Ventilation Systems: Application & Design Guide, a pdf available from Greenheck's web site.

Ideal duct size depends somewhat upon the temperature of the duct, but generally the air velocity should fall between 1000 and 2000 ft/min for minimizing grease deposition from the smaller end of the grease particle spectrum that has made it past the baffles or whatever hood filtering approach is being used.

kas

hmm, you sound very informed Kaseki, but could you please reframe in more a more simple way? I may have a lot of education but I did not take a course to help me understand what you are saying!

macswim: My comments are already a boiled down extrapolation of commercial kitchen ventilation information (of which there is a lot that is widely available) to the less well described residential kitchen ventilation needs, consistent with my sense of expected air flow (fluid dynamics) behavior. Clarity may be improved by reviewing my previous comments over the past few years as I have tried to explain concepts in different ways at various times.

Education provides both background and practice for future self education and problem solving. Engineering education may not provide expert instructional or writing skill, for which I would be happy to defer to others if they showed up here to help.

In any case, perhaps you have a specific question that I can elaborate upon. It is possible to be simple by telling someone what to do without explanation, but that at best helps only one reader.

Ok! I will take some time and find some of your previous post and see if I can understand better. Always great to have experts explain things on this site. I'm afraid I have a learning curve here. But you have given me a challlenge!

If you own a Fulgor Milano range, what do you think? We are particularly interested in the induction model.

Yes, your tile is awesome! You should post it on the Kitchens Forum for people to ogle :), and provide the brand name.

And your hood looks really great too.

Houzz Kitchens Forum