When selecting an under-cabinet range hood, one of the most important factors to consider is its CFM, or Cubic Feet per Minute. The CFM rating measures the volume of air a range hood can move in a minute, indicating its ventilation power. A higher CFM means the hood can remove more smoke, grease, steam, and odors from your kitchen. But how do you know what’s the right CFM for your specific cooking space? This article will help you understand what is under-cabinet range hood, what constitutes a good CFM for an under-cabinet range hood and how to choose the best one for your needs.
What is an Under Cabinet Range Hood and How Does It Work?
An under-cabinet range hood is a kitchen appliance installed beneath the upper cabinets, directly above your stove or cooktop. Its primary function is to remove smoke, steam, odors, grease, and heat produced during cooking. By ventilating the air, it helps maintain a cleaner, more comfortable cooking environment.
An under-cabinet range hood works by either venting air outside of the home (ducted) or filtering it and recirculating it back into the kitchen (ductless). These range hoods are designed to be mounted underneath the cabinets, typically above the stove or cooktop. Their main function is to capture and remove smoke, steam, grease, odors, and other airborne contaminants produced during cooking, helping to maintain air quality in the kitchen. And when selecting an under-cabinet range hood, one of the most important specifications to consider is the CFM (Cubic Feet per Minute) rating.
Why is CFM Important?
CFM is crucial because it determines the effectiveness of your range hood in ventilating your kitchen. An under-cabinet range hood works by drawing in the air from your stovetop area, filtering out grease and smoke, and then venting the cleaned air outside or recirculating it. If the CFM is too low, the hood won't effectively remove cooking contaminants, leaving your kitchen stuffy or smoky. On the other hand, if the CFM is too high, the unit may be louder than necessary or waste energy.
What is a Good CFM for Under Cabinet Range Hood?
You can determine your CFM requirements through various methods, taking into account factors like the size of your range, the layout of your kitchen, and the type of range hood you’re considering. Here’s what to keep in mind:
- Stove Type – Electric or Gas
- Room Size
- Range Hood Installation Height
1. Ducted Range Hoods for Electric Cooktops
Electric cooktops typically generate less heat than gas ones, so you won’t need as high a CFM.
A common guideline is:
CFM per square foot of kitchen:
Typically, you need about 1 CFM for every square foot of kitchen space.
Example:
For a kitchen that's 10 feet by 10 feet (100 square feet), you would want a range hood with around 100 CFM.
2. Ducted Range Hoods for Gas Cooktops
Gas cooktops produce more heat, so they require more powerful range hoods. The key factor here is the BTU (British Thermal Units) output of your gas stove.
To calculate the CFM for a gas stove:
Add up the BTU ratings of all burners on your cooktop. A typical gas stove might have burners ranging from 5,000 to 15,000 BTUs each.
A four-burner stove with an average output of 10,000 BTUs per burner will total 40,000 BTU.
Divide the total BTU by 100 to estimate the CFM you need for your range hood.
Example:
Total BTU: 40,000 BTU (from a 4-burner gas stove)
CFM Calculation: 40,000 ÷ 100 = 400 CFM
So, for a stove with 40,000 BTU, you'd need a range hood fan rated at 400 CFM or higher to properly ventilate your kitchen.
3. Calculate the Room's Volume
Multiply the length, width, and height of the room to find the total cubic feet.
For an open-concept kitchen with a size of 20' x 20' and 10' ceilings:
20′×20′×10′=4,000 cubic feet
20 ′ ×20 ′ ×10 ′ =4,000 cubic feet
Determine the CFM Requirement
The range hood should exchange the air in the kitchen every 4 minutes (15 times per hour). To determine the minimum CFM needed, divide the room volume by 4:
4,000 cubic feet÷4=1,000CFM
4,000cubic feet÷4=1,000CFM
Thus, a range hood with a 1,000 CFM rating (or higher) is ideal for this space.
4. Range Hood Installation Height
The greater the distance between your stove and range hood, the more powerful the range hood needs to be in order to effectively remove heat and smoke. For example, if your range hood is installed more than 3 feet above the stove, you may need a higher CFM model to properly remove airborne contaminants.
What is a Good CFM Airflow?
Most residential range hoods typically range from 200 to 600 CFM. To determine the optimal airflow for your kitchen, it's best to use the formulas provided earlier, which calculate CFM based on your kitchen's size and/or the BTU output of your gas cooktop. When comparing two options, choose the one with the higher CFM. This allows you to operate the range hood at lower speeds while still achieving the necessary performance.
How to Decide On A CFM Number
With so many factors to consider, how do you determine the right calculation? It's simple—choose the highest CFM requirement. Look for a range hood that provides the power you need while ensuring quiet operation. Additional features to consider include adjustable fan speeds, dishwasher-safe baffle filters, touch panel controls, energy-efficient LED lights, and a hood design that complements your kitchen’s aesthetic.
Ciarra range hoods deliver high-performance solutions suitable for most kitchens. Their Under Cabinet Range Hoods meet or exceed professional standards, ensuring your home stays healthy and free from smoke and odors, even when your cooktop is running at full capacity.
Choosing Your Ciarra Range Hood
Our Ciarra closet range hoods offer airflow ranging from 200 to 450 CFM, making them ideal for small to medium-sized kitchens. They are easy to install under your cabinets and come with a recirculation kit, giving you the flexibility to set up your range hood for either outdoor venting or as a recirculating model.
The Dangers of Not Using Your Kitchen Exhaust Fan
Neglecting to use your kitchen exhaust fan can expose you to significant health risks due to indoor air pollution. In the short term, pollutants like smoke, grease, and cooking fumes can irritate your eyes, nose, and throat, and cause headaches, dizziness, and fatigue. These symptoms may subside with limited exposure. However, prolonged exposure to poor air quality in a poorly ventilated kitchen can lead to more severe long-term health issues, including chronic respiratory diseases, heart disease, cancer, and, in extreme cases, even death.
To protect your health and maintain a clean living environment, always use your kitchen exhaust fan while cooking, especially during high-heat cooking methods like frying or grilling.
Conclusion
Choosing the right CFM for your under-cabinet range hood involves considering your kitchen's size, the power of your stove, your cooking style, and other factors like noise and ductwork. As a rule of thumb, aim for 100-150 CFM per burner on your stove, and adjust based on the overall square footage of your kitchen. With the right CFM, your under-cabinet range hood will effectively eliminate cooking odors and grease, improving both the comfort and cleanliness of your kitchen.