Cooker Hood Dimensions & Installation Factors – A Complete Guide
Choosing and installing a cooker hood isn’t as simple as selecting the model that best matches your kitchen decor. There’s a world of cooker hood dimensions, regulations, and placement considerations to factor into your decision.
Whether you’re redesigning your kitchen, replacing an old hood, or delving into the details for the first time, my comprehensive guide will walk you through all the essentials of cooker hood dimensions.
Let’s get into it!
What height should a cooker hood be?
When installing a cooker hood, it’s crucial to get the height just right. It’s not merely about aesthetics; the height can affect the efficiency of your cooker hood.
The exact height at which a cooker hood should be installed will be dictated by the cooker hood and hob (cooktop) manufacturer. The lowest distance requirement between the two appliances, whether it comes from the hob or the hood manufacturer’s instructions, should be the one you adhere to.
The type of hob and cooker hood, its extraction method, and the quality of its build are all factors that influence the exact minimum installation height.
When in doubt, always refer to the manufacturer’s guidelines for both appliances.
Following these instructions will ensure the safety and efficiency of your kitchen ventilation, providing an optimal cooking environment.
In the UK, there are some general height guidelines when it comes to installing a cooker hood above your hob. These guidelines aim to ensure safety and efficiency.
Here’s what you need to know:
The guidelines outline that induction hobs require the cooker hood to be installed at a minimum height of 65cm (approximately 25.6 inches) above the hob.
Induction hobs generate heat within the pan rather than emitting it, meaning they stay cooler than gas or traditional electric hobs. Therefore, the risk of damaging the extractor with heat is lower, but the distance is maintained to ensure optimal extraction efficiency.
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Ceramic (Electric) Hob
For an electric hob, the minimum height for the installation of the cooker hood is 65cm (approximately 25.6 inches) above the hob. The same as an induction hob/cooktop.
This is the minimum distance and can be increased if necessary. However, keep in mind that as the distance increases, the efficiency of the extractor at capturing steam and odours may decrease.
For gas hobs, the minimum height between the hob and the cooker hood increases to 75cm (approximately 29.5 inches). Gas hobs generate more heat and have the additional risk of naked flames, so the increased distance helps to reduce these risks.
For most models of angled cooker hoods, the recommended minimum distance the lowest point of the extractor should be installed is 45cm above an induction or ceramic (electric) hob and 65cm above a gas hob.
Ceiling Cooker Hood
Generally, ceiling cooker hoods can be installed at a minimum height of 65cm above a cooking surface. It’s also generally recommended that they do not exceed an installation height of more than 150cm above a hob or cooktop.
These are the general standard guidelines for hood installation in the UK. However, you should always refer to the manufacturer’s instructions for any specific guidance related to your particular model.
Is There A Maximum distance between the hob and An extractor?
No, there isn’t a defined maximum distance. However, there is a minimum recommended distance between the hob and the extractor (65cm for electric hobs and 75cm for gas hobs).
While there is no set maximum distance, it’s crucial to note that the effectiveness of the extractor decreases as the distance from the hob increases.
The further the extractor is from the hob, the harder it will be for it to catch all the odours, steam, and smoke generated during cooking. This is highlighted more prominently in the case of ceiling extractors as the distance is much greater.
Therefore, while installing, it’s essential to strike a balance between safety, aesthetics, and extraction efficiency.
Why Cooker Hood Height Matters
The height of cooker hoods matters as it directly influences the safety and efficiency of your kitchen’s ventilation. It dictates the hood’s ability to effectively extract heat, steam, and cooking odours.
The primary reason for setting a minimum distance is safety.
- Heat: Hobs, especially gas ones, produce significant heat. Having a cooker hood installed too close to the hob could potentially lead to damage to the hood, or even worse, cause a fire risk.
- Flames: In the case of gas hobs, there’s the added risk of the open flame. If the hood is too close, there’s a risk of flammable material in the hood (like grease filters) catching fire.
- The capture of steam and odours: The cooker hood needs to be at a certain height to effectively capture steam and cooking odours. Too close to the hob, and it could only extract from a portion of the hob’s surface. Conversely, too high, and it might not capture all steam and odours effectively.
Standard Sizes for Cooker Hoods
Cooker hoods, like hobs, come in a variety of standard sizes to cater to diverse kitchen configurations and cooking needs. Here’s a list of the most common cooker hood sizes you’ll find in the market:
Standard Width Sizes
- 60cm (approximately 23.6 inches): This size is perfect for smaller hobs or for kitchens where space is limited.
- 70cm (approximately 27.5 inches): A slightly larger size that offers more extraction coverage.
- 80cm (approximately 31.5 inches): An ideal size for larger hobs or for people who often use several burners at the same time.
- 90cm (approximately 35.4 inches): A popular size to accommodate larger 5 zone/ring hobs.
- 100cm (approximately 39.4 inches): A large hood for extensive hobs or kitchens with significant cooking activities.
- 110cm (approximately 43.3 inches): A suitable size for large range cookers.
- 120cm (approximately 47.2 inches): Typically, the largest standard size available, ideal for larger range cookers or wider panoramic hobs.
Remember, these are standard sizes, but specific models and brands may offer hoods in other, non-standard sizes. Always measure your hob and kitchen space before purchasing a cooker hood to ensure it fits appropriately and provides adequate coverage for your cooking area.
What size cooker hood do I need? (Width)
When selecting the width of your cooker hood, there’s one golden rule to remember:
Your cooker hood should be at least as wide as your hob, if not, slightly wider.
This allows it to effectively capture and extract the cooking odours, smoke, and steam that rise from all the burners on your hob.
Throughout my kitchen design career and at every kitchen company I have worked for, I have always worked under the rule that the cooker hood width must at least match the width of the hob (cooktop).
Most manufacturers of hobs will also advise this as well.
However, some studies suggest the optimum size of your cooker hood should be 1.5x the size of your hob.
|Hob/Range Width (cm)||Ideal Cooker Hood Width (cm)|
|60||60 – 90|
|75||75 – 112.5|
|80||80 – 120|
|90||90 – 135|
|100||100 – 150|
|110||110 – 165|
|120||120 – 180|
I would recommend you go for a cooker hood up to 1.5x larger than your hob/cooktop if you intend to have a gas cooktop and/or you do a lot of cooking with strong spices.
Having a larger cooker hood will mean you get a stronger extraction rate and better coverage above your hob.
What Cooker Hood Extraction Rate Do I Need?
When it comes to cooker hoods, the extraction rate is a vital factor that determines how effectively the appliance can remove steam, smoke, and odours from your kitchen. But how do you know what extraction rate you need? Let’s break it down.
Understanding Extraction Rate
The extraction rate, usually measured in cubic meters per hour (m³/h), indicates the amount of air that the cooker hood can extract from your kitchen in an hour. The higher the extraction rate, the more powerful the cooker hood is, meaning it can deal with more intensive or frequent cooking.
How To Calculate the Required Extraction Rate
To determine the extraction rate you need, you’ll need to calculate the volume of your kitchen first. You do this by multiplying the kitchen’s length, width, and height. For instance, if your kitchen is 4 meters long, 3 meters wide, and 2.5 meters high, your kitchen’s volume is 4 x 3 x 2.5 = 30 cubic meters.
Once you know your kitchen’s volume, the recommendation is that your cooker hood should be capable of refreshing the air in the room 10 times per hour. So, in our example, you’d need a cooker hood with an extraction rate of 30 (kitchen volume) x 10 (air refreshes) = 300 m³/h.
Factors to Consider
However, this is a general guideline, and certain factors might require you to opt for a higher extraction rate. For example, if your kitchen is particularly prone to smoke or you frequently engage in high-temperature cooking methods such as frying or grilling, a cooker hood with a higher extraction rate could be beneficial.
It’s also worth considering the layout of your kitchen. If your kitchen is open-plan or directly connected to a dining or living room, a cooker hood with a higher extraction rate might be needed to ensure that cooking smells don’t drift into the other areas of your home.
While the size of your kitchen provides a general guide for your cooker hood’s extraction rate, it’s essential to consider your cooking habits and kitchen layout as well.
Remember, a more powerful hood is typically louder, so you’ll need to balance extraction power with noise levels to find a cooker hood that fits your needs perfectly.
Where Should I Position My Cooker Hood?
Choosing the right position for your cooker hood is crucial for maximum effectiveness and convenience. Here’s what you should consider when deciding on the placement.
Directly Over the Hob
The cooker hood should ideally be placed directly above your hob. The central position ensures that it can effectively capture and extract steam, smoke, and cooking odours produced while cooking.
Regardless of whether your hob is situated against a wall or on an island, the hood should align centrally for the best performance.
As discussed earlier, the cooker hood should be at the right height above your hob. For a standard flat chimney or integrated cooker hood directly above gas hobs, the cooker hood should typically be around 75cm (approximately 29.5 inches) above the hob.
If you’re using an electric or induction hob, the distance may be around 65cm (approximately 25.5 inches).
However, always refer to your cooker hood manufacturer’s guidelines for specific recommendations.
Whether your cooker hood is vented externally or recirculating air can also affect its position. If it’s vented externally, you’ll need to place it somewhere where a vent can be easily installed, such as on an exterior wall.
If it’s recirculating air, you’ll have a bit more flexibility in terms of positioning, as you won’t need to consider external venting.
So, the perfect position for your cooker hood depends on your hob’s location, your kitchen’s layout, the type of hob, and the venting system of the hood.
By considering all these factors, you can ensure that your cooker hood is well-placed to keep your kitchen fresh and free of unwanted cooking odours.
Cooker Hood Ducting
When installing a ducted cooker hood there are certain guidelines you should take into account. These are meant to ensure that the extraction system works effectively and safely. Here are some of the key points to note:
Cooker hoods have a designated ducting size, typically measured in millimetres (mm). This measurement refers to the diameter of the ducting pipe. The manufacturer of the cooker hood will provide guidelines on the ideal ducting size.
It’s important to stick to these recommendations, as using the wrong size can negatively impact the hood’s extraction efficiency and noise levels.
The vent that expels air outside should ideally be positioned on an external wall. Regulations suggest that the vent should be at least 30cm (approximately 12 inches) away from a window or door to avoid extracted air from re-entering the house.
Length and Number of Bends
The length of the ducting and the number of bends should be kept to a minimum, as each can reduce the hood’s efficiency. A longer duct run and more bends or turns will make the fan work harder to expel the air.
The Building Regulations Part F (Ventilation) suggests that the ducting should be as short and straight as possible.
The ducting should be made of a heat-resistant material to cope with the warm air being expelled. Ideally, it should also be smooth inside, to help with airflow. The most common choice is rigid PVC pipes.
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How far can you duct a cooker hood?
The distance you can duct a cooker hood primarily depends on the model’s power, the ducting’s diameter, shape and the number of bends in the ductwork.
As a general rule, however, the shorter and straighter the ducting path, the more effective your cooker hood will be.
Understanding Ducting Distance
Every cooker hood usually has a maximum ducting length, beyond which the effectiveness of the extraction is compromised. This maximum length typically refers to a straight, unobstructed run of ducting.
Any bends or turns in the ducting effectively increase the length because they create additional air resistance, making the fan work harder to expel the air.
Effect of Bends on Ducting Distance
A common guideline is that each 90-degree bend in the ducting is equivalent to an additional 1 meter (approximately 3 feet) of straight ducting, while a 45-degree bend adds about 0.5 meters (approximately 1.5 feet).
So, if your cooker hood has a maximum ducting length of 5 meters (approximately 16.4 feet) and you have a ducting run with two 90-degree bends, your straight ducting should not exceed 3 meters (approximately 9.8 feet).
This is a general guide and the exact amount can vary. I’ve read some reports that claim a 90-degree bend is the equivalent of as much as a 6m straight run.
You get the idea though. Keep it as short and straight as possible!
Duct Diameter’s Role
The diameter of the duct also plays a significant role in determining the maximum length of the ducting.
Larger diameter ducts allow for longer duct runs because they reduce air resistance, thus permitting the hood to effectively expel air over a greater distance.
The specifications provided by the manufacturer of your cooker hood should always be your primary reference when planning the ducting. They will indicate the maximum ducting length and recommended duct diameter, taking into account the cooker hood’s motor power and design.
Remember, a shorter, straighter duct run will generally allow your cooker hood to function more effectively. Always consult with a professional if you’re uncertain about your specific situation.
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Cooker Hood Installation Height Regulations in the UK
|Type of Hob||Minimum Height from Hob to Cooker Hood|
|Electric Hob||650mm (approximately 25.6 inches)|
|Induction Hob||650mm (approximately 25.6 inches)|
|Gas Hob||750mm (approximately 29.5 inches)|
Keep in mind that these are general guidelines for minimum distances. While there’s no set maximum height, installing the hood higher can reduce its effectiveness.
Always refer to your manufacturer’s instructions for specific guidelines, as they can vary based on the model of your cooker hood and hob.
Can My Cooker Hood Be Smaller Than My Hob?
While it’s technically possible to have a smaller cooker hood than your hob, it’s not generally recommended. The cooker hood’s width should ideally be equal to or larger than the hob’s to ensure effective extraction of steam, odours, and smoke.
If the hood is smaller, it might not cover the entire hob, resulting in a less efficient extraction process and potentially leaving parts of your kitchen exposed to cooking by-products.
Can My Cooker Hood Be Bigger Than My Hob?
Yes, your cooker hood can be larger than your hob, and in fact, it’s often recommended for optimal extraction. A cooker hood that’s the same size or up to 1.5 times larger than your hob will ensure maximum coverage of the cooking area, more effectively capturing steam, smoke, and odours.
Keep in mind the design aesthetics and space constraints of your kitchen when choosing a larger hood.
what size cooker hood do I need for a 90cm hob?
For a 90cm hob, a cooker hood of the same size (90cm) would work effectively. However, if you want to ensure maximum extraction coverage, particularly if you frequently use all burners simultaneously, you might consider going up to 1.5 times larger.
This would mean a cooker hood size of up to 135cm. (Although, that’s probably overdoing it if you ask me)
Always remember to consider your kitchen’s design and space constraints when deciding on the hood size.
There you have it! Everything you need to know about cooker hood dimensions and all the important measurements and installation factors.
Whether it’s understanding the right size, selecting the ideal extraction rate, or figuring out the optimal position for your cooker hood, you’re ready to make an informed choice.
Remember, the perfect cooker hood for your kitchen blends both aesthetics and functionality, providing you with a comfortable, smoke-free, and pleasant cooking environment.
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Michael is a kitchen designer from the UK. He's been designing and project managing new kitchen installations for over 10 years. Before that, he was an electrician and part of a team that fitted kitchens. He created Kitchinsider in early 2019 to help give people advice when it comes to getting a new kitchen.