Your guide to buying
a range hood
Step 3.2 How to choose the amount of power - Cooking Stove
In this step of this range hood buying guide we're going to take a look at your stove power. You might ask yourself: what does my stove have to do with anything? Good question. Your cooking stove produces a certain amount of heat, you know, to cook stuff. Well, this heat will need to go somewhere. In most cases, your range hood will need to capture it and either transport it outside or recirculate it. That’s why the maximum power of your range hood and the maximum power of your cooking stove need to match up. Chances are you already have a stove and aren’t willing to buy a new one based on the power of your future range hood. That’s why we’re going to flip it around and check the power of your cooking stove, so that we can find a range hood which matches the power of your stove.
The power of your stove is measured in some-thing called BTU, which stands for British Thermal Units. Technically, one BTU is the amount of heat you need to raise the heat of one pound of water by one degree Fahrenheit, but, since that’s not really necessary to know, you can immediately forget that fact. Just know that BTU measures the maximum
amount of heat coming from the gas burners on your cooking stove. Finding the BTU of your stove is pretty easy and straightforward: check the manual of the stove. Some people might panic because they’ve thrown out their manual right after they unpacked their current range hood. For those people: look at the brand of your stove and use Google to find the details.
Question 6.1: Write down the total amount of BTU your gas cooking stove has.
For those of us who are allergic to numbers and math, let us warn you, there are some numbers ahead. Don’t worry, it’s incredibly easy!
Now that you have the BTU of your cooking stove, we can check how many CFM your future range hood will need. (The PDF will do this automatically.) To do this we’re going to use the 100-to-1 rule:
Your range hood needs to have at least 1 CFM per 100 BTU.
Let's make it a bit less abstract by using an example. Let's say your cooking stove has 4 gas burners.
- 2x small burner of 5000 BTU each
- 1x big burner of 7000 BTU
- 1x high powered work burner of 15000 BTU
When we add up the BTU of all four burners, we will get 32000 BTU. Since the 100-to-1 rules says that we need 1 CFM for every 100 BTU, all we need to do is divide 32000 by 100 and we’ll have our answer:
What about the people with an electric cooktop?
Firstly, we will have to check how much power our current electric cooktop has. So, either check your cooktop’s manual or Google the brand + model. But, keep in mind that electric cooktops/electric ranges (both (induction and ceramic) don’t use BTU measurements. Instead, your cooktop's power is measured in Watts. As many people will know, a Watt isn’t a measurement of heat (like with
BTU), but rather a measurement of how much energy an appliance or electronic device uses. But, don’t worry about that. Go check the Wattage of the individual heating elements and write them down. (If your manual states things in KW, know that 1KW = 1000 Watts.)
Question 6.2: Write down the total amount of Watts your electric cooktop has.
Great job! Since we can’t directly compare Watts and CFM, we will have to convert the amount of Watts to BTU before we can check the amount of power our future range hood will need. If you're using our PDF, you can skip this part and continue to the next page, because your BTU will automatically be converted to CFM.
For your convenience, we’ve put together a handy table of the most common heating element Wattage. So, take the Wattage you wrote down and convert them to BTU by using the table below. Once you’ve done that, add up everything and you will have the total amount of Wattage of the heating elements on your electric cooktop.
Alternatively, if the Wattage of your stove’s heating elements fall outside ones in the table you could also calculate the total amount of BTU yourself by adding up all the Wattage of the individual heating elements and multiplying the total amount by 3.41214163513 (sorry for the ultra long number).
After calculating the amount of BTU our electric cooktop has, we’re going to use the 100-to-1 rule again (1 CFM per 100 BTU) to get the CFM. Simply divide the total amount of BTU your electric cooktop has by 100, and voila, there’s the necessary power of your future range hood in CFM.
Example electric cooktop
Let's use an example again to make it less abstract. For example, let’s say your electric cooktop has the following heating elements:
When we look at the table, we see that 1200W and 1800W are included.
- According to the table, a 1200W heating element corresponds to 4100 BTU. Since we have two heating elements of 1200W, we have 2 * 4100 = 8200 BTU so far.
- The 1800W heating element corresponds to 6150 BTU, which means that we have 8200 BTU + 6150 BTU = 14350 BTU so far.
- The 2600W heating element isn't in our table, so we will have to calculate it ourselves by multiplying it with the ginormous number from before (3,41214163513). That results in 8871,57. Let's round it up to 8900.
- This gets us to 14350 + 8900 = 23250 BTU
- The '1 CFM per 100 BTU' rule says that we can get the necessary power of the range hood by dividing the BTU by 100. That will be 23250 / 100 = 232,50 CFM
(This guide will be continued on the next page.)
Next page: How big is your kitchen?
That's it. Great job! That wasn't too difficult, right? On the next page we will get to know how much power your range hood will need based on how big your kitchen is. No worries, we'll keep it short and simple. It will also be the last page on range hood power. You're almost done!