Range Hoods and Kitchen Ventilation: The Guide Nobody Reads Until It Is Too Late

Here's the pattern: a homeowner spends months choosing cabinets and countertops, then picks a range hood in the last week because "they're all basically the same." Six months later, the smoke alarm goes off every time they sear a steak, and a film of grease is settling on the living room bookshelf forty feet away. Range hood ventilation is the least glamorous decision in a kitchen remodel and one of the most consequential — especially in the open-plan layouts that dominate Bay Area remodels. This is the guide to read before you buy.

Why Open Plans Raise the Stakes

When Bay Area homeowners take down the wall between kitchen and living space — the signature move of the modern remodel, from Eichler updates to Victorian rework — they also remove the barrier that used to contain cooking byproducts. Smoke, steam, and aerosolized grease no longer stay in a small room where a mediocre fan could eventually clear them; they drift across your sofa, your art, and your guests. In an open plan, the hood isn't an appliance. It's the only line of defense.

Add today's cooking equipment — 48" pro-style ranges, high-BTU wok burners, indoor grills — and the ventilation math changes entirely from what your 1970s kitchen was built for.

Sizing: How Much CFM Do You Actually Need?

Hood capacity is measured in CFM (cubic feet per minute). The honest sizing rules:

• Gas ranges: a common rule of thumb is 1 CFM per 100 BTU of total burner output. A typical 4-burner residential gas range (~50,000 BTU) wants roughly 500 CFM; a 60,000+ BTU pro-style range wants 600+.
• Electric and induction: less combustion byproduct, but steam and grease are the same — 300–450 CFM handles most residential cooking well.
• Island hoods: cross-drafts steal capture. Upsize by roughly 100–150 CFM over the equivalent wall hood, and go wider than the cooktop if you can.
• Capture area beats raw CFM. A deep hood that overlaps the cooktop by 3" per side at the right mounting height (typically 30"–36" above the cooking surface) outperforms a stronger fan with a shallow, undersized canopy.

Ducted vs. Recirculating: The Honest Version

A ducted hood exhausts air outside. A recirculating hood pulls air through a charcoal filter and blows it back into the room. Manufacturers sell both, so let's be plain about the difference: recirculating hoods remove some odor and some grease, and precisely zero heat, moisture, or combustion byproducts. Everything a gas burner produces stays in your house.

Recirculating has a legitimate place — condos where the exterior wall is unreachable, historic constraints, rental refreshes. But in a full remodel where walls and ceilings are already open, running a real duct is nearly always achievable and always worth it. If your remodeler shrugs and specs recirculating in a single-family home, ask why.

Duct Runs: Where Good Hoods Go to Die

A 900 CFM hood breathing through a 25-foot run of 6" flex duct with four elbows delivers nowhere near 900 CFM. The rules that protect your investment:

• Smooth-wall rigid metal duct, not flex, for the full run.
• Match the duct diameter to the hood outlet — necking an 8" outlet down to 6" to squeeze through a joist bay strangles the fan.
• Short and straight wins. Every elbow costs the equivalent of several feet of run; plan the hood location with the duct path in mind, not as an afterthought.
• Terminate outside with a proper wall or roof cap — never into an attic or crawlspace, which just relocates the grease and moisture problem into your framing.

Makeup Air: The Requirement Nobody Budgets For

Here's the one that surprises almost everyone. High-CFM hoods move serious air out of your house, and that air has to come from somewhere. In a tight, modern-code home, a big exhaust fan can depressurize the house enough to backdraft combustion appliances — pulling flue gases from a water heater back into living space. That's why building codes generally require a dedicated makeup air system when hood exhaust exceeds a threshold (commonly 400 CFM), typically an interlocked damper that opens to admit outside air when the hood runs.

Practical translation for your remodel: crossing the 400 CFM line can add a motorized damper, ducting, and sometimes tempering to your project. Sometimes the 600 CFM hood with a great capture canopy is the smarter spec than the 1,200 CFM statement piece plus a makeup air system. This is exactly the kind of tradeoff a design-build kitchen remodeling team should be modeling for you during design — with the mechanical plan, the permit drawings, and the budget all reconciled before anything is ordered. It's the sort of coordination we've handled on Bay Area kitchens since 2012 (CSLB #975092).

Hood Styles and the Noise Question

Insert (liner) hoods hide inside custom cabinetry or a plaster surround — the favorite for current Bay Area design, where the hood disappears into the architecture. Wall-mount canopy hoods make the hood a focal point. Island hoods hang from the ceiling and need the extra capacity noted above. Downdrafts are a compromise of last resort; physics wants smoke to rise, and downdrafts fight it.

On noise: hood loudness is rated in sones. Around 1 sone is refrigerator-quiet; 4–7 sones at high speed is common and loud enough that people simply don't run the hood — which makes it worthless. Two ways to win: buy a hood that moves your target CFM at a low-to-middle fan speed, or spec a remote/inline blower that puts the motor in the attic instead of over your head.

Frequently Asked Questions

Is a recirculating range hood good enough for a gas range?

It's better than nothing, but it returns heat, moisture, and combustion byproducts to the room. For gas cooking in a single-family remodel where a duct path exists, ducted range hood ventilation is the clear answer.

Do I really need makeup air?

If your hood exceeds the code threshold — commonly 400 CFM — plan on it. It protects against backdrafting combustion appliances and is part of the permit conversation, not something to discover at final inspection.

What matters more, CFM or hood size?

Capture area and mounting height, then CFM, then everything else. A wide, deep canopy at the right height with 600 honest CFM beats a shallow designer hood claiming 1,000.

Get the Ventilation Right the First Time

Ventilation is a design decision, not an appliance purchase — duct path, makeup air, and hood style all have to be settled while the walls are open. Planning a kitchen project anywhere from Napa to Carmel? Request a free consultation and we'll spec the whole system alongside your layout. Our free planning guides are worth a read before your first design meeting.

Related reading: Common Kitchen Remodel Problems in Older Bay Area Homes · Porcelain and Sintered Stone Countertops: The Complete Guide