How much CFM do I need for my Range Hood?
In this article we will discuss why the type of cooktop you have will determine the Range Hood or Vent Hood that will best suit your needs. A range hood over a gas cooktop will need to be larger and require higher CFM than a vent hood over an electric cooktop of the same size. Though many think bigger is better, that is not always the case. A range hood removes the air from your cooking area, whether it’s smoke, grease, air conditioned or heated air. So if you live in a warm climate with the air conditioner running non stop, and draw out 1200 CFM, just remember your cooled air is being extracted as well. It’s important to have the right amount of CFM for the right cooking style and environment.
The right Range Hood for Electric Cooktops…
An electric cooktop is most commonly used by consumers. Though we all want the best Range Hood possible, a simple rule of thumb is 10 CFM for every inch of width in your cooktop. For example, if you have a 30” cooktop you will need a minimum of 300 CFM for your range hood. There are other things to consider that would require additional CFM which we will discuss later in this article, but there is the basic answer.
* Electric cooktops need 10 CFM for every inch of cooktop width.*
One advantage of using an electric cooktop is that gas isn’t being used to generate the heat, therefore the additional heat created by burning gas does not have to be exhausted as well. You only need to remove the heat, smoke, grease and odor created by the food you’re cooking.
The right Range Hood for Gas Cooktops…
Gas cooktops are popular, especially with serious cooks and there are many high output gas cooktops available today. With a gas cooktop, you burn Propane or Natural Gas which mixes with oxygen in the air, it expands and then rises. The volume of exhaust from a gas cooktop requires a considerable amount of air to be removed to ensure the cooking area maintains a constant temperature.
For Gas Cooktops, the most widely accepted standard being used in determining the CFM for your Range Hood is based on the total BTU’s or British Thermal Units produced by the cooktop. BTU’s are a measurement of maximum heat that each burner, grill or griddle puts out.
The standard rule for Gas Cooktops is a minimum of 100 CFM of airflow for every 10,000 BTU’s of heat energy. For example, you have a 48” gas cooktop with 6 burners and a grill. Add the total BTU’s for each burner and the grill, let’s say it was 60,000 BTU’s for the burners and 20,000 BTU’s for the grill totaling 80,000 BTU’s. With 100 CFM’s for every 10,000 BTU’s that means you will need an 800 CFM Range Hood.
Other things to consider…
Now that you know how to calculate the standard CFM needs for both Electric and Gas Cooktops there are a few other things to consider. The coverage area, the height the Range Hood is mounted above the cooktop, your cooking style and design all play a big role in your Vent Hood performance.
The higher you mount your Range Hood, the more CFM you will need in order to vent the air properly. Never mount your Vent hood closer than 28 inches above your stove top or you risk melting parts of your hood.
The way your hood is ducted can require additional CFM. The length of the ductwork, the amount of 90 degree bends and the diameter of your ducting will all add additional CFM needs.
If your cooking style has you frequently cooking extra greasy or pungent foods, you will also want more CFM to keep your kitchen air free from airborne contaminants.
Finally, if your Vent Hood is mounted over an island, it will have to compete with more cross breezes than a wall mounted hood, thus requiring additional CFM.
Thanks for reading, I hope you find this information useful in assisting you in determining the CFM needs for your new Range Hood.
Have Fun and Happy Cooking!