A question that I am often asked is does having more blades on a fan better for air circulation? I am going to try and answer that in this article. So let’s get started.
In principle the answer is yes they do. The more blades that you have on a fan, the easier it is for those blades to move air. If you ever look closely at a fan, the first thing you will notice is that the blades are set at an angle. The angle is designed to almost cut or curve its way through the air. That in turn, creates a breeze, which pushes the air slightly upwards.
Now if those same blades then spin faster, then they will start to move the air about quite quickly.
Here is a good video that covers the basics of what makes a fan work.
How Many Blades on a Fan is Best?
Most fans will comes with either 5 or 7 blades. Now there are of course some fans with a different amount of blades. The most popular however remain as the 5-blade option. That really is the optimum for a high performance fan. The size of the fan is however important to note. Trying to cram a large number of blades into a small circle or diameter is not that practical.
Even small fans can of course pack in a number of blades. However their effectiveness becomes diminished if their surface are is too small. So, in other words, the surface area and the angle of the blade, is what helps push the air around. Once you start to reduce the surface area of the blade, then its effect also reduces.
Fan Blade Alignment
Something that is often overlooked is the actual alignment of a fan. I have already mentioned that the blades are always curved. However blades normally come as a set. These are usually set a certain distance apart. This is known as the alignment. The purpose of that design is to make the fan more efficient. When the blades all work together, then that assures that the fan will move the most air.
Here is another interesting video on how a fan blade is designed.
Understanding Double Blades
Some fans also use double blades. As the name would suggest, they basically double up on the blades, which are of course carefully aligned. Some manufacturers prefer these to a standard single blade. They will of course increase the cost of making the fan. In my opinion, I don’t think that they make a huge difference for the average fan, that is used in the home.
One of the most common problems with fans is sticking blades. What will typically happen is that the blades may slow down, or indeed stop turning at all. Now in most cases that is probably down to the motor. However in some cases it can simply be that the fan blades are out of alignment, or that they have simply got dirty.
The blades are normally connected to the shaft. Dirt and grease build up around that shaft, and that can start to slow the blades down, or even stop them altogether. A simple clean up can usually do the trick. A quick clean and some oil can quickly get your fan working again.