Knowing and understanding your options is the first step towards laying the right exhaust system in your kitchen. For instance, if you're considering over-the-range microwave ovens, you should know that they are not the best when it comes to venting smoke and oily fumes (unless it's ducted externally).
On the other hand, it's possible that you've got an island range and some beautiful ceiling decor in your kitchen which you don't want to obstruct. Yes, there are plenty of stunning island range hoods that add to the beauty of a kitchen (and I do recommend some of them), but you do have other options, such as kitchen ceiling exhaust fans or downdraft range hoods (some of you may have heard that downdraft ventilation systems are the worst, this was the case until a few years ago).
All I'm saying is that it's wise to understand the many possibilities before you set your mind on anything in particular.
Table of Contents: Skip What You Already Know
- Questions to Answer Before the Search
- Ventilation Options
- Types of Range Hoods
- Range Hood Lingo
- Technical Factors to Consider
Questions to Answer Before the Search
I would recommend getting a sheet of paper and a pen or probably open an app where you can take down notes. There's going to be some technical information which you must first gather from your kitchen.
Are You Replacing an Existing Range Hood
If you answered no, feel free to skip to the next question. If you answered yes, you're going to need to note down the following information:
- Is it important that your new range hood must be the exact same dimensions as the present hood? Maybe you've got a cabinet that comes in the way. If this is the case, either measure the current dimensions or look up the manual of the current range hood for this information.
- Do you already have ducting installed? If you do, it's a lot easier to use the existing duct network for your new install. Go ahead and measure the diameter of the venting pipe and also the location of the duct. Is it immediately behind the current range hood (on the wall) or does it go up through the ceiling or a cabinet?
Is Ducting an Option or Must Your Range Hood Be Ductless
If you're living in a rented home where you don't have the freedom to make major modifications, or if you live in a high-rise apartment with an island range where you can't really duct up through the ceiling, or it could be one of many other reasons (including costs) which leaves you no option to duct. Whatever the case, it is important that you know your limitations, as it helps narrow down your search.
It happens more often than you think, that people think they can vent their range hood, only to realize later that they cannot or that the vent they could install doesn't allow the range hood to really function (Probably of interest, further down in this guide: having bends in ductwork). When you're installing a ducted hood, the ductwork should never terminate into the attic, the space between walls, garages or crawl spaces. this may call for longer duct channels, so keep this in mind when determining costs.
I haven't decided yet... If you cook often, experts always suggest that you get a ducted hood as this gets the smoke, odor and other fumes out of your kitchen rather than filtered and re-circulated as in the case of recirculating hoods.
Moreover, if the cost of ducting is the problem, you should keep in mind that re-circulating range hoods require you to change the charcoal filter every few months depending on the amount and type of food you cook (if you don't it's as good as having a noise machine in your kitchen and not a range hood). It's up to you to decide whether replacing the charcoal filter which is usually around $20-30 every few months for years is a better option than a one-time investment in ductwork.
What's the Clearance?
For now it would be wise to just measure the clearance space available from the cooktop to the ceiling/cabinet above the range. Most range hood manufacturers suggest leaving a space of 20" to 24" between the bottom of the range hood and the top of the cooking surface. Unless otherwise specified, the suggested spacing for gas ranges is 24" to 30". It's important that you look into the installation manual for any specific clearance height that is defined, as this is going to effect performance.
It is vital that you not only make sure that you have enough clearance between the cooktop and the range, but you're also going to want to make sure that there is enough room for the entire appliance to fit (undercabinet installations). In case of wall mount and island cooking canopys you would want to ensure that the chimney reaches the ceiling (high ceilings). Most manufacturers offer extensions which are often sold separately. If you have a low ceiling (up to 8 feet), you may need to ask for the shorter chimney extensions. If you don't do this, you could end up cutting the telescopic chimney, and unless you are good at metal work, this never is a good option.
Other Questions to Ask Yourself
- What style and color would look good in my kitchen?
- What is my budget inclusive of all expenses: The range hood, extended warranty, installation costs, ducting, charcoal filters (non-ducted range hoods), chimney extensions (if needed), other misc. expenses.
You’ve got two options regarding the ventilation system of your range hood. You could either install it with ducts or opt to have a hood that does not duct to the outside (ductless).
Range Hoods with Ducts
It is highly recommended that you duct to the outside if you want to completely get rid of pollutants. If you have a gas stove top, it is not just recommended, but necessary that you duct to the outside, as the build-up of combustion products from the gas flame is dangerous to human health. If you’re going to be installing the ductwork yourself, there are a few important points to keep in mind:
Cross-Section Dimension of the Ducting
Depending on the power of the motor within the exhaust system, the size of your ducting would vary. A more powerful motor would naturally move more air and therefore the cross-sectional area of the duct must be sufficient to allow this volume of air to pass through unhindered.
Most range hoods come with an outlet to which your duct network must be connected. The minimum area of your duct network must be the same as the cross-sectional area of this outlet. The typical size for range hoods at home is either 6” or 8”. If you have a duct larger than the recommended, it’s not a problem. But if the duct is smaller than recommended, it’s going to lead to blow-back resistance and increased noise because of buffeting.
The Shape of the Duct
The outlet from the range hood is either circular or rectangular. If you cannot directly connect to this outlet you may need a transition piece that converts from circular to rectangular ducting or vice-versa. This website has an air flow in CFM and rectangular to circular duct converter table which may be helpful.
If you have the option to choose between a round or rectangular duct, I would suggest you go for the round duct as they offer less friction to the flow and are therefore less noisy. On the other hand, the length of the ductwork for home kitchen exhaust systems is so small that it does not really matter. If your range hood is going to be placed under a cabinet, you may want to use rectangular ducting as it is easier to hide using crown molding.
Flexible ducting may seem easy to use as you don’t have to get the measurements perfect. But I would suggest that you do not use flexible ducting unless you can stretch it, such that it is not flexible anymore. The internal ridges on the unextended ducting add to flow resistance, reducing the effectiveness of your blower and at the same time it increases the noise.
Length of the Ducting
To understand this section, you should know that CFM is a measure of the power of the motor. More on this is found in the section discussing technical range hood lingo.
The shorter your ductwork the better. If your range hood is mounted on an exterior wall, your ductwork can be very short and thus more efficient. On the other hand, if it is on an interior wall and you need to go through another room or the ceiling, or if it is over an island range, you may go over 20 feet of ducting. It is recommended that once you exceed 20 feet, you add a 100 CFM to your initial requirement to have the same suction power over your cooking range. Also, for any 90-degree bends, add another 100 CFM. Try and have as few bends as possible and if you must have bends try and keep them inclined at an angle lower than 45 degrees when possible.
Here are a few recommendations suggested on the Kitchensource website with slight modifications based on my knowledge:
- If you duct directly outside, you do not need additional CFM than what you originally calculate (Calculate your required CFM)
- If you go up a bit and then outside through a 90-degree turn you should add 100 CFM.
- If you go straight up and through the roof, you may not need to add extra power unless the ducting exceeds 20 feet.
- Pulling down using an over the range hood and then exhausting is going to need a lot more CFM as there are multiple 90 degree turns
Other Important Points Regarding Ductwork:
- The endpoint must always be outside your home
- Only use smooth galvanized metal ducting
- If a backdraft damper is not included you should add one on the outside wall, the roof cap or within the duct run.
Ductless Range Hoods
You should also check out our other page which specifically focuses on ductless range hoods and a specific ductless exhaust hood buying guide. All experts will tell you that these sorts of stove hoods are your last option and must be installed only if you cannot duct outside for some reason.
They do trap grease using their grease filters and the odors are absorbed by the charcoal filters (charcoal filters need to be replaced occasionally). However, the moisture and chemicals that results from your cooking are going to be recirculated within your kitchen. I should point it out once more, that exhaust from a gas cooking range are retained within your kitchen and you must NOT get a recirculating hood in this case, unless you can keep your windows open.
Many (but not all) ventilation hoods are easily convertible from a ducted option to the ductless option with the simple addition of a charcoal filter.
Types of Range Hoods
The layout of your kitchen is mainly going to decide the kind of appliance that you could use. However, if you're planning a kitchen re-model you can keep an open mind and check out your many options.
Among the functional range hoods (OTR microwaves not being considered), these are the most affordable of the lot and they are also the most popular because they fit in with most kitchen layouts. This hood is installed under a cabinet that overlooks your cooking range. You'd find hoods that stand out and are aesthetically pleasing, as well as hoods that do not draw much notice, which does not imply they are an eye sore. They are typically a lot lighter than the other types, which also makes them easier to install on your own. In case of ducted kitchen hoods, the duct could be either through the back and out through an exterior wall or the ducting could be on the top through a cabinet. You may be interested in checking out our thorough under cabinet range hood reviews.
Wall mount range hoods are very similar to their under cabinet counterparts in the sense that they too are attached to the wall, but they don't have a cabinet above them. These hoods are closed from three sides in order to hide the blower and other components of the system. They typically come with a flue that goes right up, exhausting through the roof, or alternatively, up and sideways. In some cases, the flue is telescopic, some would even say they are bespoke flues. They do cost more than undercabinet hoods, but give your kitchen this cool, chimney like feature. Check out our wall mount range hood reviews if this is what you are looking for.
Island range hoods are a very logical choice if you've got an island range. Very similar to the design of a wall mount hood, island hoods are closed on all four sides and typically come with telescopic chimneys. Many kitchen remodelers choose to install these because of the added aesthetics. Some island models also have a retractabilityactability option that moves the range hood up towards the ceiling when not in use, opening up your kitchen. Ducted island hoods, obviously exhaust through the ceiling or a duct that goes along your ceiling through an external wall. Lastly, it is important to add that there are island exhaust systems that are built into your false ceiling that don't stick out, they are flush to the ceiling. This may not be the best solution in terms of exhaust, but it doesn't get in the way of an open kitchen layout. Check out some of the top island range hoods we've reviewed.
Downdraft systems are often referred to as pop up exhaust systems and they are either placed on the side or behind your cooking range. They work by sucking in the exhaust fumes and pulling them down before sending the fumes out of your kitchen. They are a good option if you do not really have room for a regular hood. Most people would never consider getting one because of the bad reputation of these models. However, this system has had a resurrection over the last couple of years, with newer models that actually get the job done, not as well, but well enough. They are more expensive when compared to traditional range hoods and unfortunately you do not have a lot of good options to pick from.
Range hood inserts are another popular choice among people who love DIY projects. When you buy an insert you get all the components that make up the exhaust system other than the outer shell. You therefore have the freedom to design your hood, the way you like it and equip it with a blower, the filters and other internal components.
Range Hood Lingo
- CFM: This stands for cubic feet per minute and is a measure of the air circulation. The higher the CFM the more air the range hood can move every minute. But as most experts would say, CFM isn't everything. This is because, having a kitchen hood with a very high CFM, but a horrible capture area would not lead to very good ventilation. Also, it is a well known fact that an electric range requires a lower CFM rating than a gas stove and because ductless models do not have to throw the air out of your home, but simply pass it through filters and recirculate it, they are typically less powerful. To better understand what this (CFM) actually means, an exhaust system with a CFM of 400 would be able to completely ventilate a box of dimensions: 10 * 10 * 4 feet = 400 cubic feet. For more on CFM and a calculator that takes into account the Home Ventilating Institute requirements, check out this calculator we developed.
- Sones: The sone is a measure of preceived loudness, and it is typical that range hoods use this unit of measurement. A typical refrigerator runs at one sone and a regular conversation is around 4 sones. For more examples, I recommend you see this page on Wikipedia.
- Heat Sentry ™: Quite a few models boast of the Heat Sentry ™ feature. This is essentially a technolgy that automatically adjusts the blower speed whenever excess heat is detected.
- Charcoal Filter: Charcoal filters are an accessory that are only present in recirculating range hoods. Their main function is the removal of grease, odor, smoke and fumes. Depending on what, how and how much you cook, you're going to need to replace the charcoal filters every 4 - 8 months. There is no way for them to be cleaned and must be replaced. Some models come with indicator lights that let you know when the filter needs to be replaced. For those that do not have an indicator, it's really easy to tell when it's time to replace a hood: the moment you feel the appliance isn't working even though the fan is running!
- Grease Filter: There are typically two types of grease filters on ductred range hoods, the mesh filter and the baffle filter. To the best of our knowledge, the mesh filters are almost always made of Aluminum and the baffle filters are typically stainless steel. The main purpose of the grease filter is, as you may have guessed, to trap grease. To learn more about the difference between the two and to figure out which one works best for you, read this post on the AKDY website. Grease filters are usually dishwasher friendly and you should clean them every month. In case you've been lazy and you're grease filter is so dirty that you can hardly see the shine of metal, you may need to try other methods. This guide on cleaning range hood filters may help.
Other Technical Factors to Consider
Experts recommend that the width of your range hood be six inches wider than the width of your cooking range, three inches on either side. In some cases, you may not have this freedom due to other kitchen installations, cabinets for instance. If that's you, don't worry too much about it, a hood the same width as your cooktop functions well too, but when possible we would also recommend a hood once size larger than the cook top. Some experts would recommend that the depth (length) of your hood be the same as that of your cook top, but having a depth 2 - 3 inches less than the cook top would be ideal. This also gives you more breathing room while you cook. The height of the range hood needs to be determined based on many factors, please take a look at our detailed guide on determining the dimension of your kitchen hood.
The required power of the fan depends on what you're cooking and how you're cooking it. Boiling water, deep frying food and warming up food, all call for different fan speeds, i.e. suction power. This is why most range hoods have variable speeds, up to 6 different speeds in some cases. If you look into the manual, it is very likely that the manufacturer would have specified which power setting needs to be used for a particular kind of cooking process. If you don't want to be bothered with determining the necessary speed of your fan, you could opt for a range hood with the heat sentry feature. This feature automatically increases or decreases the fan speed according to the amount of heat it senses.
This is a big one, a feature most people do not think too much about. Hoods come with all sorts of lighting options, some use halogen bulbs and the others LEDs. Some models allow you to switch to a light bulb of your choice provided you do not exceed the maximum allowed wattage. If your kitchen is bright enough and you do not need the extra light, you don't need to worry too much about this feature, but if you do need the extra lighting, make sure that you're happy with the intensity, color (yellow, white or blue light) and the possibility to adjust the direction of the light bulbs.
Ease of Installation
Many range hood models do not come with very good manuals. If you're not very experienced at DIY projects, you may find it challenging to install one without the right instructions. Therefore, before placing an order make sure that you read some reviews and find out for a fact whether the included manual was helpful or not. In the worst case scenario, you could check out some helpful videos on Youtube.
In some cases, the range hood is very heavy and it would be near impossible for a regular person to install the hood on his or her own. If that's your hood, make sure that you know of someone who can help you out. Something else that you may want to keep in mind regarding the installation is the electrical connection of the range hood. Some models need to be hardwired whereas others come with a plug. Lastly, it is worth repeating that in some cases you may need to hire professional help for the installation, keep this in mind when setting up a budget.
Automatic Shut Off
An interesting feature to have is that of the auto shut-off. In order for the range hood to do its job and to completely refresh your kitchen after you're done cooking, it is wise to leave it on for a while, albeit at a lower speed. Some models come with the built in function of an auto shut-off where the appliance is turned off after 15 minutes of you asking it to. You can of course, override this feature and switch it off immediately. A few models also give you the option to program this setting and change the time to shut-off.