When you are looking for a ceiling fan you might be curious to know how much CFM a fan should be able to push for your space. Each fan comes with a different CFM because of differences in the size and shape of the blades, motor power, and so on. So, let’s have a look at what’s best for you.
This chart will guide you on how much CFM a ceiling fan needs for the space (in square footage):
|<200 sq. ft. (<18.58 sq. m)
|200-300 sq. ft. (18.58-27.87 sq. m)
|300-450 sq. ft. (27.87-41.81 sq. m)
|>450 sq. ft. (>41.81 sq. m)
Go through this guide to learn how to determine the right CFM for your space based on the room’s square footage. This guide will also allow you to choose the right ceiling fan so that you cool down your space without consuming too much energy.
Determining How Much CFM a Fan Needs for Your Space
Most ceiling fans offer a CFM of more or less 4,000, but some of them range from 2,000 to 10,000 CFM as well. In general, you will go for the CFM that is ideal for the space as well as you can; more isn’t always better. A higher CFM will cause higher energy usage, and you will consider an energy efficient while generating enough air to keep your room cool and dry.
You will be able to decide how much CFM you need if you know the room’s square footage you need to cool. The right CFM per square footage is posted in the presented table above.
Just remember that those measurements suppose the height of the room to be about 8 feet (2.44 m) tall. If your room is taller or shorter than these measurements, the needed CFM will be slightly changed than what’s described.
Calculating the Square Footage of a Room
Before you start to determine the right CFM for your room, you should find out what the room’s square footage is. It can be done by measuring the length of the area using its width. If you are familiar with the space size in square yards, you can get the reading by multiplying it by three as there are 3 feet (0.91 m) in each yard.
If your room contains a closet, measure the square footage of both of them, the main room and the closet and then add them together. Typically, kitchens and bedrooms are about 200-300 sq ft (18.58-27.87 sq. m), and living rooms are more or less 300-450 sq ft (27.87-41.81 sq. m).
The amount of CFM your fan will use for the place depends on the size of your place. Bigger rooms require more CFM because they have more air.
CFM is used to calculate the efficacy of a fan by measuring how many cubic feet of air are generated per minute. The measurements of CFM will tell you that the fan is moving at the highest speed possible. It is entirely dependent on the shape and size of the fan and the power of the motor.
Airflow efficiency is computed by dividing the CFM by the watts used to make the fan work. Ideally, your fan will contain an appropriate CFM and also a low wattage of power use relative to the amount of air generated.
To get a fan with high airflow efficiency, you need to find a fan with a powerful motor and slightly tilted fan blades containing a blade pitch of about 13 inches (33.02 cm).
Factors That Influence a Ceiling Fan’s CFM
The influence of CFM still depends on the rotation of the fan per minute rate, the blades’ size, the tilting of the blades, the height from the ceiling, and the quality of the motor.
Rotations per Minute
You can find the fan’s rotations per minute by the rotational speed of the motor of the fan. Most fans come with a rotational speed of about 300-350 RPM, although high-speed fans can go to 380-390 RPM.
A fan with a high RPM will generate a higher CFM because it can circulate enough more quickly.
Usually, the ceiling fan comes with at least six different speed level, the speed levels are from low to high. You can maximize the efficiency with different speeds and it will be suitable for your needs too.
A high RPM will do a lot of things on its own, however. It should be attached to blades with a correct pitch and a motor with enough electricity to generate the air in a proper manner.
When a ceiling fan contains bigger blades, every rotation produces more air, increasing the overall CFM. Generally, ceiling fans are designed with a blade span of 40-65” (101.6-165.1cm), although you will be able to see bigger blades on the market if you are looking for a fan for your larger area. Just keep in mind the bigger blades require more energy to spin, so you need a fan to be suitable for the place not to be the biggest one.
Blades are different in size in a matter of width and length, so you need to consider both when selecting your unit. You also have to make sure that blades are compatible with the motor because the mismatch between them will result in a major malfunction.
The more a ceiling fan is tilted, the more it generates air as it rotates, and the more energy it consumes from the motor to turn around. Generally, fan blades contain a tilt of around 13-inches (33.02 cm), although they can be around 14-15 degrees. This measurement is also known as the pitch. Blade tilt is also responsible for the energy consumed like the blade size when rotating the fan, so more is not always good.
Flatter blades do not put too much effort into the motor when they move as compared to more tilted ones. With more tilt, it needs a more powerful motor to push them and generate more air as they rotate. If your fan tends to wobble, it can be happening due to the lack of a steep pitch, overworking the motor without pushing air very vigorously.
If your ceiling fan becomes worn out or breaks down quickly, it could be happening due to the too much steep blades, putting too much effort on the motor that is not strong enough to do it.
When it comes to the CFM of a fan, the quality of the motor is very important factor as it depends on the amount of energy being used into transforming airflow. A higher-quality motor will generate air faster, giving rise to the rate at which air is refreshed in the room and as a result, boosting the CFM.
Ceiling fans that have powerful motors are very costly, so you need to invest more to get these kinds of fans.
Height From the Ceiling
Generally, to circulate the air in the room in a proper way, a ceiling fan should be at least 10-12” (25.4-30.48cm) from the ceiling. However, some ceiling fans called hugger ceiling fans are made to work flush against the ceiling.
If you have vaulted ceilings, you may have to maintain a larger distance between the ceiling and the fan.
If that is the case, you need to ensure that the fan is about 8-9 feet (2.44-2.74 m) up from the floor.
The CFM that you need for your ceiling fan is entirely based on the size of the room you want to install it in. bigger rooms need more CFM whereas smaller rooms can use less CFM. The CFM depends on the size of the fan, its blades and the speed the fan spins, and the degree that the blades pitch or tilt. Just remember, CFM is only one of the factors that you need to decide when choosing a ceiling fan for your room. So, you need to make the right decision that fulfills all of your requirements.