The Battle of Cooling: Fans Vs. Air Amplifiers

So, you have a cooling application and don’t know what to choose; do you go with the age-old fan or something different. Fans are probably one of the most common items used for cooling in everyday life and chances are you have a few that are always cooling. These fans can be found in cars, at your home, in your computer, and many other places.

But there may be other items that might just blow away the competition (pun intended). This is where EXAIR’s Air Amplifiers step onto the scene. Air Amplifiers use a little bit of compressed air to entrain the surrounding ambient air to turn it into a large volume of air.

Axial Fan being used to cool down an electrical cabinet

When it comes to cooling with air, volume is key. Air cannot hold a lot of thermal energy (heat) so in order to cool something down you need a lot of it. This means that the unit that can produce the largest volume of air is going to produce more cooling. So, what is the difference between a fan and the air amplifiers and which is better?

Fans have been in use since late B.C.E. and are still in use today. Many of the fans used for cooling are centrifugal style fans which are also known as blowers. These systems use an impeller that consists of a central shaft with blades that form a circle around a central opening. Blowers produce a high volume of air at a high velocity and low pressure. Not only do blowers require significant space to install, they also require noticeable maintenance and will eventually need to be replaced. Another, and perhaps more important downside, is that a blower will increase the temperature of the outlet air which further reduces the air’s ability to absorb additional heat and effectively cool.

Super Air Amplifier Family

On the other hand, Air Amplifiers use a source of compressed air to form a thin stream of high velocity laminar flow of air to entrain the surrounding ambient air. By doing so you can create a focused blast of air for cooling. So the downside in this case is that if you do not have a source of compressed air, the Air Amplifier will not function for you. With a small amount of compressed air, Air Amplifiers will multiply the volume of air up to 25 times to produce the large volume of air needed to cool parts, films, castings and more.

Air Amplifiers are extremely inexpensive when compared to blower systems and can out perform a blower in many applications.

If you have questions about our Air Amplifiers, or would like to talk about any of the quiet EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR or any Application Engineer.

Cody Biehle
Application Engineer
EXAIR Corporation
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FREE EXAIR Webinar – November 2nd, 2017 @ 2:00 PM EDT

On November 2, 2017 at 2 PM EDT, EXAIR Corporation will be hosting a FREE webinar titled “Optimizing Your Compressed Air System In 6 Simple Steps”.

During this short presentation, we will explain the average cost of compressed air and why it’s important to evaluate the current system. Compressed air can be expensive to produce and in many cases the compressor is the largest energy user in a plant, accounting for up to 1/3 of the total energy operating costs. In industrial settings, compressed air is often referred to as a “fourth utility” next to water, gas and electric.

Next we will show how artificial demand, through operating pressure and leaks, can account for roughly 30% of the air being lost in a system, negatively affecting a company’s bottom line. We will provide examples on how to estimate the amount of leakage in a system and ways to track the demand from point-of-use devices, to help identify areas where improvements can be made.

To close, we will demonstrate how following six simple steps can save you money by reducing compressed air use, increasing safety and making your process more efficient.

CLICK HERE TO REGISTER

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Proper Air Supply Is Key To Optimal Performance

I recently worked with a customer who was using our 36″ aluminum Super Air Knife to remove dust and light debris from a conveyor but wasn’t seeing good performance. They initially called because they read in their catalog that increasing the shim gap would increase their force and flow and wanted to know what kind of increase in performance they would see.

The Super Air Knives are shipped from EXAIR with a .002″ shim installed and the performance data shown in the catalog reflects this gap setting. The shim sets, for aluminum knives, include a .001″, .003″ and .004″ shim and by changing to the .003″ shim, the force and flow would be 1.5 times as great and using the .004″ shim would double these amounts. While some applications do require the additional force and flow, trying to blow off dust or light materials typically wouldn’t fall into this category.

sak-shims
Replaceable shims provide varying levels of force and flow.

Switching our focus to the supply side of things, it turns out they were using 1/4″ hose and only plumbing one end of the unit. This poses 2 concerns that relate directly to the mentioned poor performance. The first would be the 1/4″ hose is severely undersized for a 36″ Super Air Knife. We recommend 3/4″ Schedule 40 pipe if the length of supply from a main header is 10′ or less and a 1″ pipe up to 50′ of supply run. It is possible to use hose but that hose needs to be at least 1″ ID to be able to carry enough volume to support a 36″ unit. Secondly, for knives that are 24″ in length or longer, you need to plumb air to both ends to maintain an even, laminar flow across the length of the knife.

With the proper supply, the Super Air Knife is going to produce an exhaust air velocity of 11,800 feet per minute when operated at 80 PSIG, which is more than enough to eject lightweight material from a flat surface (in fact you could most likely clean dust and light debris at a lower pressure). If the customer did increase the shim gap dimension, the increase in  air demand would only worsen the problem of undersized supply lines.

Pipe sizes
Recommended supply line sizes per the IOM – Installation and Operation Manual.

This is just one example of how proper supply line size and installation is key to achieving optimal performance. If you are experiencing similar issues or need any assistance with a product or application, give me a call, I am glad to help.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN