Outdoor Kitchen Ventilation: When You Need a Hood and What CFM to Buy

Prices verified 30 August 2026. Prices change — check the product page for current pricing.

You generally need a vent hood when a grill is installed under a solid roof, a covered patio, a lanai, a pavilion or any other enclosing structure, and you generally do not need one when the grill sits in fully open air. That is the shape of the answer, not the answer itself: whether ventilation is required for your specific installation is determined by your grill's installation manual and your local building code, and it must be confirmed with a licensed professional before you build. No retailer — including us — can tell you what your installation requires. Hoods in our range run from $1,949 to $5,499, and the ducting, spacers and duct covers that make them work are separate purchases that routinely add $500 to $2,000.

When ventilation is generally needed

Under a solid roof. A grill under a permanent roof structure — a covered patio, a porch, a lanai, a pavilion, an outdoor room with a ceiling — is producing smoke, grease-laden vapour, heat and combustion products in a space that does not clear on its own. This is the situation vent hoods exist for.

Under any structure that traps air. Ceiling height, how many sides are enclosed, prevailing wind and roof pitch all change how much a space actually clears. A three-sided outdoor room with a low ceiling behaves very differently from a tall open-sided pavilion.

Where the manufacturer's manual says so. Grill manufacturers publish their own requirements for installation under overhead structures, including minimum clearances to combustible materials above and beside the grill. Those requirements are specific to the model and are not transferable between brands or even between series within a brand.

When ventilation is generally not needed

Fully open air. A grill in a freestanding island with open sky above it does not typically need a hood. Smoke rises and disperses. This covers most backyard outdoor kitchen islands.

Pergolas and open slatted structures. These sit in the middle and are exactly where general rules stop being useful. An open-slat pergola is not a solid roof, but it is also not open sky, and whether it counts as enclosing depends on the structure, the materials above the grill and how your local authority reads it. This is a question for your code official and a licensed professional, not for a category page.

The governing authority is the manual and local code — always

We want to be blunt about this because ventilation sits next to two genuine hazards: combustion products in an enclosed space, and heat and grease near combustible construction.

The requirements that govern your installation are, in order: the installation manual for your specific grill model, the installation manual for the specific hood, your local building and mechanical code, and the judgement of a licensed professional who has seen your structure. Gas connection, clearances to combustibles, duct routing, duct material, makeup air and electrical supply are all in that set. We will not state a clearance figure, a duct length, a code requirement or a mandatory CFM number for your build, because none of those can be known from here — and a figure invented to sound helpful is worse than no figure.

If you are in the Charleston area, the practical sequence is: get the grill and hood manuals, take them and your structure drawings to a licensed installer, and confirm with your local authority before anything is framed.

CFM: a rule of thumb, clearly labelled as one

The following is a widely used rule of thumb. It is not a code requirement, not a formula, and not a substitute for the manufacturer's manual or a licensed professional's judgement.

Rule of thumb one: the hood should be at least as wide as the appliance below it, and many installers go wider. A common approach is to run a hood that extends a few inches beyond each side of the cooking surface, so a 36-inch grill gets a 42-inch hood and a 42-inch grill gets a 48-inch hood. The reasoning is simple — smoke plumes spread as they rise, and a hood only captures what passes under it.

Rule of thumb two: CFM scales with appliance BTU and with how much you smoke. A higher-output grill, a grill used for long smoky cooks, or a run that includes a power burner boiling stock, all push toward more airflow than a modest gas grill used for weeknight burgers.

What we will not do is give you a CFM formula. Published rules that convert BTUs into a required CFM figure vary by source and none of them account for your ceiling height, duct run length, number of elbows, hood mounting height or makeup air. The hood manufacturer publishes a sizing recommendation for its own products, and that recommendation — read alongside your local code and a licensed professional's assessment — is what should decide the number. Our outdoor kitchen hood FAQs cover the same ground from a different angle.

The actual hoods: 16 real hoods in our range

Worth knowing before you browse: our outdoor hoods collection holds 40 items, but only 16 of those are hoods. The other 24 are accessories — spacer brackets, duct covers, duct cover fillers and wye fittings. Those accessories are not optional extras dressed up as products; several of them are required to actually install the hood you buy. Here are the 16 hoods.

Hood	Width	Stated CFM	Price
TrueFlame TF-VH36-2	36"	1,000	$1,949
TrueFlame TF-VH42-3	42"	2,000	$2,399
TrueFlame TF-VH48-3	48"	2,000	$2,899
TrueFlame TF-VH60-3	60"	2,000	$3,999
TrueFlame TF-VH72-3	72"	2,000	$5,499
RCS RVH36A	36"	1,000	$2,804
RCS 48" Outdoor Vent Hood	48"	2,000	$3,219
Falmec Zeus 36"	36"	1,200	$2,579
Falmec Line 36"	36"	1,200	$2,699
Falmec Zeus 42"	42"	1,200	$2,799
Falmec Pyramid 36"	36"	1,200	$2,799
Falmec Line 42"	42"	1,200	$2,899
Falmec Zeus 48"	48"	1,200	$2,899
Falmec Line 48"	48"	1,200	$2,999
Falmec Pyramid 42"	42"	1,200	$3,199
Falmec Pyramid 48"	48"	1,200	$3,399

TrueFlame TF-VH: the widest size range

TrueFlame's TF-VH line covers five widths from 36 to 72 inches, which is the broadest span of any hood family we carry and the reason it turns up on most long island runs. Every size from 42 inches up carries a 2,000 CFM motor; the 36-inch TF-VH36-2 ($1,949) is the exception at 1,000 CFM.

All of them ship with a mounting bracket. Note that the accessory ranges split at the 36-inch model: spacers and duct covers for the TF-VH36-2 are separate part numbers from those for the TF-VH42-3, TF-VH48-3, TF-VH60-3 and TF-VH72-3. Quote the model code, not the width, when you order parts. Browse the range in TrueFlame.

Falmec: design-led, 1,200 CFM across the board

Falmec fields three canopy shapes — Zeus, Line and Pyramid — each in 36, 42 and 48 inches, all rated 1,200 CFM. Because airflow is constant across the sizes, choosing a wider Falmec does not cost you CFM and choosing a narrower one does not gain you any. You are choosing width for capture and shape for looks.

Falmec builds these in AISI 304 stainless with baffle filters and its NRS noise reduction system, and the Line 36" ($2,699) is listed as outdoor approved. One structural constraint matters more than any spec: these are wall mount hoods. They need a wall or a chase behind them to fasten to and to carry the duct. If your grill sits in a freestanding island with open space on all sides, a wall mount hood is the wrong product and you need an island-mount solution instead. The Zeus 36" ($2,579) is the least expensive way into the range.

RCS: two widths, full spec published

RCS keeps it simple with two sizes. The RVH36A ($2,804) is 36" x 30" x 18" in 304 stainless with a single 1,000 CFM blower, adjustable fan speed, dual interior lights, eight vent filters and a 10-inch duct collar included, running on a 115V 15-amp supply. The RCS 48-inch hood ($3,219) steps up to 2,000 CFM.

The RVH36A's published detail is unusually complete, which makes it easy to plan around: you know the electrical requirement, you know the duct collar size, and you know the filters are in the box. See more in RCS.

Ducting, spacers and duct covers: the line items people forget

A hood is not a finished installation. Three categories of part sit between the hood you order and the hood that works, and none of them are included.

Duct pipe itself is a separate purchase. The RCS RVH36A includes a 10-inch duct collar; the pipe from that collar up through the structure is not part of the package. Duct size, length, material and routing must follow the hood manufacturer's installation requirements and your local code.

Spacer brackets set the mounting height. Mount a hood too high and it stops capturing; too low and you have a clearance problem. Spacers fine-tune the position for your ceiling. They are model-specific and they are not cheap: the TrueFlame 8" spacer for the TF-VH42-3 is $799, the 4" spacer for the same hood is $629, and on the largest hood the 8" spacer for the TF-VH72-3 runs $1,399. On the RCS side, the 8" spacer for the RVH36A is $429 and the 4" spacer is $364. The correct mounting height comes from the hood's manual, not from a rule of thumb.

Duct covers enclose the exposed pipe. Without one you are looking at bare duct between hood and ceiling. The TrueFlame 22"–43" telescopic duct cover is $649 for the 42-inch and larger hoods, or $549 for the TF-VH36-2 version. A fixed duct cover is $479. RCS lists the RVH36ADC duct cover at $269. Small filler pieces close the gaps: TrueFlame filler pieces run $59 for the 1/2", $79 for the 4" and $109 for the 8".

Routing fittings. Where the duct has to turn or split, the TrueFlame wye duct fitting is $199.

Add it up honestly. A TF-VH42-3 at $2,399 plus a spacer and a telescopic duct cover is comfortably past $3,500 before a licensed installer touches it. Budget accordingly, and see the outdoor kitchen cost guide.

What actually matters

Electrical supply. Hoods need power for the blower, lights and controls. The RCS RVH36A specifies 115V, 15 amp. Plan the circuit into the structure before it is closed up; retrofitting is far harder. Electrical work is a licensed electrician's job.

Wall mount versus island mount. Decide this before you shortlist. Every Falmec hood in our range is wall mount and needs a wall or chase.

Never use an indoor range hood outdoors. Indoor hoods are not built for outdoor weather, moisture, grease loads or grill heat. Use a hood rated for outdoor use.

Burners and griddles vent too. A power burner boiling a stock pot produces steam, and a griddle produces its own grease-laden vapour. If either sits under the same roof, include it in the covered run when you size the hood. See side burners and power burners, the side burner FAQs and the built-in griddle FAQs.

Filters get cleaned or the hood stops working. Baffle filters capture grease before it reaches the blower and the duct. Clean them on the manufacturer's schedule.

FAQ

Do I need a hood for a grill on an open patio?

Generally no, if the grill is in fully open air with nothing enclosing it. Confirm against your grill's installation manual and local code before you decide.

Do I need a hood under a covered patio?

Generally yes, and it may be required. The requirement comes from your grill's installation manual and your local building code, verified by a licensed professional — not from a general rule.

What CFM do I need?

We will not name a number for your build. As a rule of thumb, CFM scales with appliance BTU and with how smoky your cooking is, but the hood manufacturer's own sizing recommendation, your local code and a licensed professional govern the actual figure. Hoods in our range run 1,000, 1,200 and 2,000 CFM.

How wide should the hood be?

As a rule of thumb, at least as wide as the appliance below it, and commonly wider — a 42-inch hood over a 36-inch grill, a 48-inch hood over a 42-inch grill. Follow the hood manufacturer's sizing recommendation.

How high above the grill should the hood be mounted?

Take the installation height from the hood's manual. Too high reduces capture; too low creates clearance concerns. Spacer brackets exist to hit the specified height in your structure.

Does the hood come with ducting?

No. Duct pipe, spacers, duct covers and fittings are separate purchases, and several are needed for a finished installation.

Can I install a hood myself?

Installation involves electrical work, ductwork, structural mounting and code compliance. Use a licensed professional.

Do these hoods work over a pellet grill?

Pellet grills produce sustained wood smoke, which is exactly the load a hood is for. Check compatibility in both manufacturers' manuals — see best built-in pellet grills and the pellet grill FAQs.

Final recommendation

If your grill is under a roof, plan for a hood from the first drawing, not after the island is poured. For a 36-inch grill under cover, the TrueFlame TF-VH42-3 at $2,399 is the most straightforward pick: 2,000 CFM, a 42-inch canopy over a 36-inch appliance, mounting bracket included, with the widest accessory range behind it if the structure needs spacers. For a wall-backed installation where the hood is a design feature, a Falmec Zeus 42" at $2,799 earns its price on looks and noise. For the fullest published spec on a 36-inch opening, the RCS RVH36A at $2,804 tells you everything you need to plan the electrical and duct.

Then take that choice to a licensed professional along with both manuals. Ventilation, gas, clearances and electrical are not areas to work from a rule of thumb, and the requirements for your build come from your grill's installation manual, your hood's installation manual and your local code.

Everything here is orderable with free shipping and no credit card fees. Shop all outdoor vent hoods and built-in grills, or narrow by width with 36" built-in grills and 42" built-in grills. Related reading: outdoor kitchen appliance checklist, built-in grills FAQs, what size built-in grill do I need, best 36-inch built-in grills, insulating grill liner FAQs and best side burners and power burners. To talk it through with a person, use help me find my grill, request a quote, or call our family-owned Charleston store at 843-212-7209.