How does a range hood work? (Complete Guide)

What are the different types of range hoods?

1. Range Hoods

Range hoods come in several styles: Under-cabinet hoods are mounted on the bottom of a kitchen cabinet that’s directly over the stove. A wall chimney hood (or wall-mounted hood) is installed on the wall when there’s no cabinet over the stove. An island (or ceiling-mounted) hood is attached to the ceiling over a stove that sits on an island or peninsula. Most of these overhead hoods include lighting that illuminates your cooktop, and all of these styles can be found vented or unvented.

2. Downdraft Systems

Another type of range ventilation is the downdraft system, which sits beside or behind the stovetop and sucks air down to a duct that runs under the floor. These look great because they’re barely visible (they can even be retracted when not in use), but they don’t work as well as overhead hoods. (See Remodeling 101: Nearly Invisible Downdraft Kitchen Vents for more.)

3. Microwaves with Build-In Hoods

And lastly, while they’re not strictly range hoods, microwave ovens designed to be mounted over the range generally come with a hood, either vented or unvented, to recirculate air from the cooktop.

 Above: The ceiling-mounted range hood is disguise
Above: The ceiling-mounted range hood is disguised by a linoleum-fronted box in Kitchen of the Week: A Copenhagen Stylist Reinvents her Kitchen, Ikea Hack Included.

How does a ducted range hood work?

Many people get confused with a ducted and ductless range hood as both falls under the category of under-cabinet range hoods. Here’s how a ducted range hood works:

  • A ducted range hood works by pulling air through the ductwork, usually running through the ceiling or the wall.
  • It’s connected to the exterior of the house and is one of the most effective options for purifying the air in your kitchen since it vents any type of dirt, odors, fumes, grease, etc. out of the house


Can I use a Ductless Range Hood in an Outdoor Kitchen?

You can use a ductless range hood for an outdoor kitchen although it’s not really necessary. If your outdoor kitchen is underneath a covered patio, you can vent a ducted hood through a side wall or install a ductless model if you don’t want to install venting.

Ductless Range Hood Installation 

Installing a ductless range hood is considerably easier than installing a vented one. The extra work and material involved with ducted range hoods are also more expensive than ductless ones. Here’s how to install a ductless range hood. See the video below if you are looking for a ductless island range hood.

Prepare the Installation Site 

The first thing you’ll want to do is select and prepare the site for installing the range hood. You should install your ductless range hood directly above your stove or oven at the height specified by your specific model.

The height is typically around two feet above the stove. If you have an older hood already in place, you’ll want to remove it and set it aside while installing your new one. Ensure that you don’t damage the electrical wiring when you disconnect it. 

Install Strips or Wood for the Mounting Screws 

Range hoods of all kinds have a mounting bracket on top of them that gets screwed into place. Usually, you’ll want to install your hood above the stove and underneath some high cabinets. If you don’t have anything solid above the hood to screw into, you can also buy one that has a rear-mounting option. 

Either way, you should ensure you have something solid into which to fasten the mounting screws. If you don’t have studs in the wall at the appropriate spots, you’ll have to cut open the drywall and install some. Or, you can purchase heavy-duty drywall anchors.

However, you must have at least one or two solid spots to attach your screws to. Otherwise, the hood’s weight will cause it to detach from the wall and come crashing down. 

Start by Properly Placing the Hood and Mounting It 

Once you have a solid area behind or above your range hood, hold it in place and mark the holes in the bracket where the screws go through.

Some hoods come with a template that you can use to mark the insertion points, but it’s always a good idea to hold the hood up and visualize the project. Use a pencil to mark the holes on the bracket. 

Next, take the bracket down and set it aside until you’re ready to hang it. You’ll notice that there are notches where two bracket holes are.

Range hoods have this feature so that you can partially tighten the screw and tentatively mount the bracket without completely fastening it. Do this now before proceeding to the final steps. 

Fasten the Hood in Place 

Once you have your hood exactly where you want it, tighten the screws that you initially started. Next, insert a few extra screws into holes on the bracket and in areas where you have something solid to screw into. You want to make sure that your hood is solid and unmoving for years to come. 

Connect the Electrical Wiring 

With the hood in place, it’s time to make your electrical connection. If you removed an old hood, use the same electrical wire you disconnected from the old one. If you’re installing a new hood without existing electricity, you’ll first have to run an electrical wire to the correct location before you can connect it to the hood. 

At any rate, follow the instructions on your range hood directions to connect the electrical wiring properly.

Typically, there is a black wire, a white wire, and a green wire. Connect the black supply wire to the black wire on the range hood and the white supply wire to the white wire on the hood. Lastly, connect the ground wire to the green screw on the range hood as per the instructions. 

Install the Light Bulb and Perform a Practice Run 

Your final step is to install the light bulb on the range hood and perform a practice run. Ensure that the power is turned on to the hood and hit the ON switch. Your ductless range hood will turn on, and you should hear a fan startup inside the hood. 

Double-check the surface parts of the hood to make sure you remove all the tape and insulation used to hold pieces in place. You should also make sure that the filter is correctly installed so that your hood can do its job. 

You would follow a similar procedure with a ducted range hood with the added step of installing a vent. Vents can be easy to install, or they can be an absolute pain in the neck. It depends entirely on the size of the vent pipe and how easy it is to get through an outside wall or roof. 

Under The Hood

Photo by Pete Bleyer

Ducted or not? Venting the polluted air out of your house is always preferable to recirculating it. Recirculating fans use charcoal filters to clean the air and release it back into the house when ducting to the outside is impossible, as in many apartment buildings. When it’s the only option, a recirculating hood is better than no ventilation at all, but this type should never be used with pro-style appliances.

Think about power. The amount of air the blower moves, measured in cubic feet per minute (cfm), is one of the biggest factors to consider when choosing a hood. The larger and more powerful your burners are, the more cfm you need. (See “Calculator” section below.)

Photo by Joe Schmelzer

Measure it right. A hood should be at least as wide as your cooking surface, but an extra 3 inches on each side can improve efficiency. The depth should cover the back burners and at least half of the front burners, though full coverage is best. The height at which the hood hangs above your cooktop will also affect how well it works.

A wall- or island-mount should be about 30 inches above the cooktop, while undercabinet-mounts, typically less powerful and with smaller ducts, should sit 24 inches above the range. If you want to place the hood higher than recommended, you’ll need a wider unit—extending 3 inches beyond both sides of the range—and more cfm to compensate. (See “Calculator” section right below.)

Consider the noise. To avoid a loud fan, check the sones (1 sone equals about 40 decibels). A fan set on low typically comes in under 1 sone, but high speeds can jump to 10 or more. For a quieter unit, look for one that’s 6 or fewer sones at 600 cfm.

Is a vented range hood better than an unvented one?

Without question. It’s far preferable to vent the air outdoors than to recirculate it into the room. A vented hood that removes steam, smoke, heat, and cooking odors is the best way to keep your kitchen clean, since it gets rid of grease particles that would otherwise accumulate on your walls and cabinets.

Unvented range hoods do filter some grease and cooking odors from the air, but the general consensus is that they’re nowhere near as effective. Nor do they remove heat and humidity, so they won’t help keep your kitchen cool while you cook.

 Above: An industrial-style vent (made of ducting)
Above: An industrial-style vent (made of ducting) draws air up and out. For more, see Kitchen of the Week: A Proper English Kitchen with New England-Inspired Shiplap Paneling.

Vent Hood Vitals: Important Questions to Ask

How much does it cost?

Prices vary, depending on size, functionality, and style. A basic 30-inch hood can be had for under $100, while a custom copper 60-inch ceiling-mount chimney-style one can go for more than $20,000. Most mid-priced, high-style hoods can be found for around $1,000.

DIY or hire a pro?

Swapping in a similar unit is a simple job that requires basic electrical work to connect the wiring. To install a new vent, you’ll need to cut holes in the walls, ceiling, or roof and run ductwork. This could be a project for an experienced DIYer or might best be left to a contractor.

Where to buy?

You can order a variety of hoods online or find them at appliance retailers, showrooms, restaurant suppliers, and home centers.

What about maintenance?

Experts recommend cleaning the filters after every 30 hours of use—typically every month or two—to keep a hood running smoothly.

Installing A Recirculating Range Hood

When you install a ducted range hood, there are two round or square cutouts, one at the top and one in the rear.

These cutouts are removed depending on whether you want to have a vertical duct to the roof, or a rear duct to the wall.

Of course, if you want to use the range hood as ductless, then you simply keep the cutouts in tact.

The installation is significantly simpler than having to install a duct to the outside or even just having to reconnect the duct. The basic installation procedure is to screw the range hood to the wall studs and hook up the electrical wiring or plug it in.

You don’t have to worry about the wall duct, the exterior vent cover, and possibly even going on the roof.

One common problem with ducts is that it creates a wall penetration that can allow in exterior air and animals. I have frequently found birds nests in vents which is one reason that there is a flapper.

Read Also: How To Vent A Bathroom Fan Into An Attic?

Do range hoods have to be vented outside?

Your range hood can either vent to the outside if it is a ducted range hood. Or, you can purchase one that recirculates the air in your kitchen; those hoods are called ductless range or vent hoods. If you want the job done right, ducted range hoods are more efficient and powerful than the ductless ones.

But some people may not be able to duct their hood to the outside. The most common situation we run into is people who live in an apartment or condo. These customers can’t install ductwork either due to their building codes or because they live in a multi-story complex where they can’t duct to the outside.

If you fit that description, consider a ductless range hood for your kitchen.


Maintenance of both ductless and ducted exhaust systems is important to ensure the longevity of your exhaust system and the safety of your home. Built-up grease can even cause a fire in your exhaust system. In addition to cleaning and changing your filters, you should have a professional regularly inspect your ducts and conduct preventative maintenance. If you own a home, check out our guide for cleaning your kitchen exhaust and if you own a restaurant, you can read more about how to clean your kitchen hood in our previous blog post.

How does a range hood filter work?

A range hood filter captures grease and dirt from your kitchen air. The most common types of filters are baffle and mesh filters. Ductless hoods use charcoal filters which trap grease and neutralize odors before the air moves back into your kitchen. Replace your charcoal filters after about every 120 hours of cooking. If you use baffle filters, clean these every three to six weeks depending on your cooking style.For more information, check out the articles below.

How to Clean Your Range Hood Filters

How often should I replace my charcoal filters?

Range Hood Filter Guide

The Pros Cons of Different Types of Vent Hoods

By weighing the various advantages and disadvantages of each type of hood, you can better decide which one is most suitable for your particular kitchen.

Ducted Range Hoods: The Good & Bad

Ducted Range Hoods: The Good & Bad

Ducted hoods are commonly found in commercial kitchens or homes that have larger ranges that tend to generate greater amounts of smoke, fumes or dirty air that should be vented outside.

Ducted hoods tend to be more efficient for getting rid of humidity and steam from the cooking area due to the fact they are not actually filtering and recirculating the air, but are instead venting it out of the kitchen completely.

Some people claim that ducted exhaust systems run more efficiently, and tend to me more quiet. This is debatable, however, as efficiency and noise production will differ depending on the brand, size, model and how well you take care of your range hood.

One of the few drawbacks of a ducted hood is that it must be installed in an area where there is a duct system that goes from inside the kitchen to the exterior of the home or building. This can potentially limit the areas in the kitchen where you can actually position your range and hood.

Ductless Range Hoods: The Good & Bad

A ductless hood has the advantage of being a bit more versatile and can be installed just about anywhere you please. Because a ductless range hood merely filters and then recirculates air throughout the kitchen, you do not need to worry about installing it near any pipe or ducts that reach the outside.

In this way, a ductless hood can be more convenient than a ducted system, at least in regard to the installation process. Some ductless models even run on timers and can be programmed to turn on or off automatically.

The ductless range hoods are not without their disadvantages, unfortunately. For this type of hood, due to the fact that it recirculates air instead of pulling in new air or venting out stale and dirty air, your kitchen may become fairly humid. The decibel levels of a ductless hood may be a bit higher than ducted exhaust systems due to the fact that they often require much more fan power. Again, this will be dependent on many factors, including the brand, size and model you choose.

It is also important to remember that the filter needs to be cleaned or replaced regularly for optimum performance. This may mean an ongoing cost for the homeowner.

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