Although the international CFM code for range hoods is 100CFM, some local authorities allow for range hoods with slightly lower or higher CFM than this, depending on the type of your cooking, and the square footage of your cooktop.
The standard height for a range hood is between 28 and 36 inches from the cooktop for a gas range and electric range. 28 inches is the minimum height. If the hood is any closer, it may become damaged. Any further than 36 inches and your hood won't move air away from your cooktop efficiently.
In restaurants, vent hoods are required. This is what the ICC Mechanical Code says: “Type I hoods shall be installed where cooking appliances produce grease or smoke as a result of the cooking process.” Commercial vent hoods require make up air and a fire suppression system to ensure their safe use.
Range hood vents should always be located on the outside and they need to terminate at least 3-feet away from windows, doors, and other vents such as bathroom fans. If you have a powered air intake such as from a high efficiency furnace, then the range hood vent needs to be at least 10-feet away.
Range hoods do not have to be vented to the outside. You can purchase hoods without ductwork called ductless hoods. But, ducted range hoods are almost always preferred over ductless hoods.
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.
A ductless (or ventless) range hood does not vent out of the home, instead, it carries the debris and smoke form the air and filters it through a charcoal or carbon filter before releasing it back into the room. While many times this method is not as functional as a vented hood, it does work.
An exhaust fan is required in a kitchen. A kitchen exhaust fan removes particles, smoke, carcinogens, and odors from your kitchen's air. They prevent your house from filling up with cooking smoke and setting off alarms. Many local residential building codes require them.
Both wall and under cabinet range hoods can be vented on an interior wall. Venting a range hood on an interior wall may seem daunting. But, if you are comfortable DIYing it, you can save money doing the installation yourself. If not, we recommend hiring a local contractor to install the hood.
In general, most installations require a distance from 20" to 24" between the bottom of the hood and the cooking surface. Over a gas range, this distance should be between 24" and 30", unless otherwise specified.
The truth is that you should consider a vent for your electric stove. Even if you cook one or two times a week, a vent hood can be beneficial for you. It will clean your indoor air and improve your indoor air quality. For electric stoves, we recommend a range hood of at least 600 CFM.
If you have a gas range, install your range hood 24 to 36 inches above your cooktop. If you have an electric range, install your range hood 20 to 24 inches above your cooktop. If you have an outdoor grill, install your range hood 36 to 42 inches above your cooktop.
As seen in this article, a range hood is quite important even when used over an electric stove. It adds to the aesthetic appeal of your kitchen, boosts your home's resale value, and eliminates gases and fumes, leaving you with a clean kitchen area.
For example, for a 30” range, a 36” hood is ideal. Then, subtract 2” and you get 34”. So a 34” hood insert or larger is a great fit for a 30” range. For outdoor applications, go with an insert two sizes larger than your range.
Can flexible duct be used for a range hood? No. Avoid flexible duct for your range hood, regardless of the CFM.
You must not vent into the soffits, or even under the soffits unless you are more than a foot and a half below the soffit to allow the wind to dissipate the moisture before it rises back up into the attic.
No, you should never vent your range hood into the attic. The excess buildup of grease and moisture in your attic will ruin it and over time may cause mold damage. Instead, vent your hood through an interior wall or through the ceiling all the way outside of your home.
Across the United States, the majority of residential homes cooking with gas do not need to vent their range. However, just because you don't have to does not mean that you shouldn't. If you use a commercial-style range, then you will be required to do so.
The range hood requires pipes that connect to a duct to transport the dirty air and foul odor away from the kitchen to outside. The exhaust fan effectively gets rid of the moisture in the kitchen that arises due to an increase in moisture and vapor from food preparation, a feat that the ductless fans cannot.
It's possible, though, that the range hood is vented straight through the wall to the outside. To tell if that's the case, go outside and look at the wall to see if there's a wall cap to allow the vented air to escape. Of course, if the range hood isn't mounted on an outside wall, it probably wont' be vented like this.
A ductless range hood is a kitchen exhaust fan that recirculates your kitchen air through charcoal filters instead of ductwork. Charcoal filters trap grease, dirt, and neutralize odors. Then, the air vents back into the kitchen.
The major difference between the two is that a ductless range hood, which is more common in most kitchens, uses a fan or blower motor to pull all the grease and smoke out of the air, then recirculates it. A ducted range hood, on the other hand, vents all the bad air straight to the outside.
A non ducted or ductless range hood is not the best option for gas stoves because they work by filtering the air inside the hood and returning it into the kitchen. Even if you have a hood with a high CFM rating, charcoal filters will not capture all the gas produced by the stove.
Range hoods can be recirculating with stainless steel mesh or baffle filters. To make your hood recirculating, you need charcoal filters as well. These sit inside your range hood blower and trap grease and odors produced from your cooking. Then, that air moves back into your kitchen.