It’s HOT! Not Just Outside

It’s Summer, it’s hot, and just about everywhere that sees the sun here in the US is currently pretty warm. This isn’t breaking news to anyone here in the Midwest, but it is also increasingly muggy and humid. I know this because the condensate drain on the A-Coil within my home HVAC system has been dripping more and more water down through the drain line and into the floor drain. I’ve also been watering my outdoor plants more and more frequently due to the lack of rain we have had the past month. At home, my HVAC system pulls moisture out of the air and lets it condense then pushes it down a drain. Out of sight and out of mind for most homeowners. In a manufacturing plant, that isn’t always the case because many have no climate control for their machine and production areas.

When I was in metal cutting, it was not uncommon for me to walk into a shop during the summer to repair a machine that had a thermal trip. Most of these machines that I worked on had simple air-to-air heat exchangers to cool the electrical cabinets which have a minimum of three variable frequency drives in them as well as a controller, many other relays, and circuits. Most machine shops I went into were also not climate controlled. The machining processes would build a mist and dust throughout the facility which would settle. The fan intakes would often not be maintained, and the cabinets would eventually overheat. Often, rather than cleaning the fans, the operators or maintenance would simply open the electrical panel doors and put a box fan blowing into the open panel, so they could finish cutting their parts.

Whatever you do, DON’T do THIS to your panel.

While this would put the machine back into service it would also pull in all that warm humid air from the shop that was filled with the metal fines, oil mist, and other dirt. This would then blanket the inside of the panel and all the open circuit boards. Some of the drives would even have fans on them from the manufacturer to keep the inside cool which would just internally coat the surfaces with oil, dust and debris. Then, after that job was done, it would just roll into the next job because the “fix” was working just fine. Well, after a while of the machine running like this, the buildup settling onto the boards and internal fans coating the inside of the drives the machine would generally go down again and this time they couldn’t apply the same fix of opening the doors again. This is when I would get the call and have to deliver the bad news that I now have to clean and inspect all the boards and drives. Then, when we would get finished, the cycle would start over unless the customer took to heart that the fans have a much-needed preventative maintenance cycle, or they would have the fans removed and install a Cabinet Cooler System.

The advantage of the Cabinet Cooler System is that the panels stay sealed and maintain their NEMA rating all while receiving less than ideal maintenance intervals. In fact, the Cabinet Cooler itself has no moving parts and the only maintenance is to ensure the compressed air filter is clean and clear. This option would often result in fewer calls for overheated machines. I am fairly certain it may impact the sale of box fans to these machine shops. At the very least, the operators get to keep the fans for cooling themselves off rather than blowing into an electrical enclosure.

If you have seen an open electrical enclosure with fans blowing into it, then you know exactly what I am talking about. I hope you understand that an EXAIR Application Engineer can help you prevent that safety violation as well as a general, all around bad idea for the health of the components inside the cabinet.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

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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Electrical Panel Heat Protection: Limitations of Fan Cooling

In preparation for some labor-intensive outdoor projects, I did some research into heat-related health risks, and their prevention. My first thought on prevention was getting someone else to do it, but my wife made a good case for “pride in ownership”, and I DO have a good many tools suitable for these projects. Also, I am notoriously frugal, so after getting a couple of estimates, I realized the value in a little DIY (do it yourself) and commenced planning.

High on that list of risks was the possibility of heat stroke. It’s recommended that the victim be taken to a cool space (someplace air conditioned, for example). Air flow (like from a fan) can help too, but only if they’re taken someplace where the ambient temperature is less that 95F (35C). If it’s that hot, the air flow can actually make things worse, since heat transfer requires a difference in temperature. If the cooling medium (air, in this case) is the same temperature as the object to be cooled (the human body, in this case), no heat will be transferred – and the heat stroke wins. That’s a bad day in the back yard.

This is, in fact, the exact same limitation with a popular method of electrical panel cooling: fans. We’ve been using mechanical methods of imparting motion to air for cooling purposes for a long, long time: Blowing on a spoonful of soup or a cup of coffee before a warm (but not scalding) sip, waving hand fans at oneself during indoor gatherings, installing electric fans in those same buildings, and the list goes on. Fans are inexpensive to purchase & operate, come in a variety of sizes & configurations, and are oftentimes used to circulate cooling air through occupied rooms, confined spaces, and, of course, electrical & electronic panel enclosures.

These are quite effective for panels with moderate-to-high internal heat loads, as long as the ambient area temperature is less than the temperature you wish to cool the panel’s internal air to. In those situations, the only real concern is the quality of the air in the environment. As you can see in the photo to the right, filters are an absolute “must”, and they’re going to require regular maintenance. This means cleaning or replacing the filters, as well as cleaning the fan grills and blades themselves. It’s still very likely that some of that dust is going to get inside the enclosure, and while we’re on the subject of environmental contamination, so will humidity. I probably don’t need to tell you that dirt and/or water, and electricity, don’t mix.

There are other methods of cooling (panel a/c, thermoelectric coolers, water cooled heat exchangers, heat pipes, etc.) that limit environmental contamination, but they’re still going to need periodic (oftentimes frequent) attention: filters will clog, refrigerant coils will get fouled and corrode, moving parts will wear, motors & switches will burn out, etc. Even with the advances made in refrigerant technology, the leaks that panel a/c and heat pipes are prone to are still bad for the environment.

If this sounds like your environment, and you’re looking for safe, dependable, durable heat protection, look no further than EXAIR Cabinet Cooler Systems. Using the Vortex Tube phenomenon, they generate cold air from your compressed air supply, with no moving parts to wear or electric devices to burn out. Systems are on the shelf & ready to ship in cooling capacities to 5,600 Btu/hr. We also “tailor-make” systems for higher heat loads, from stock products, that can usually ship right away as well. Once installed on a sealed enclosure, the only thing the internals of that enclosure are ever exposed to again is clean, moisture free, cold air. All of our Cabinet Cooler Systems come with an Automatic Drain Filter Separator – the only preventive maintenance that’s ever required for the systems is the periodic replacement of the filter’s particulate element.

Inside, outdoors, high temperature, dirt/dust/humidity, corrosive and classified environments are no problem for EXAIR Cabinet Cooler Systems

We can quickly and accurately specify a Cabinet Cooler System to meet your needs with just a few key pieces of information – you can fill out a Sizing Guide (or complete one online) and send it in to us, or you can call an Application Engineer with the data. It only takes a minute to do the calculations, and we do them over the phone all the time. Installation is straightforward and usually only takes a matter of minutes. We have a number of short “how to” videos on our website that cover all aspects of installation, and if you ever have specific questions or concerns, an Application Engineer is a phone call away. We look forward to hearing from you!

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Super Air Knife Cools Laminated Packaging Material

I recently worked with one of our distributors on a Super Air Knife application for a manufacturer of flexible packaging material. They create the plastic material that is commonly wrapped around the outside of a wide variety of different containers. The material exits the laminating machine at about 129°F (54°C) and must be cooled to close to room temperature before it is able to be rolled without the material sticking together.

IMG_20180509_103254_HDR
Model 110012, positioned to maximize counter-flow

They performed a test with a Model 110012, recording the temperature after the knife and determined that it would be suitable for them. Prior to using the Super Air Knife, they had been using a series of fans to cool down the material. This worked to some degree, but they had been experiencing quality issues as a result of inadequate levels of cooling and were forced to slow down the laminating machine in order to compensate. By implementing the Super Air Knife, they were able to cool the material down to ambient temperatures without having to slow production. As an added measure, they ordered a second knife to install on the underside to further decrease the temperature of the material.

sak_cooling
Graph showing the effectiveness of a Super Air Knife vs. fans or no cooling method.

The laminar airflow of the Super Air Knife is critical to the success of any cooling application. A fan “slaps” the air which provides random spikes of air at moderate velocities. The uniform, high velocity, laminar sheet of air from the Super Air Knife, in addition to the low compressed air consumption, makes it a much more effective cooling method than fans. The design of the Super Air Knife allows it to entrain ambient air at a rate of 40:1, maximizing the force and flow from the knife while keeping compressed air usage to a minimum.

super-air-knife-flow
The design of the Super Air Knife allows it to entrain air from the top and bottom, creating a 40:1 air amplification ratio.

Super Air Knives are available in a range of different materials and sizes. From stock EXAIR carries knives from 3”-108” in Aluminum, 303 Stainless Steel, 316 Stainless Steel, and 3”-54” in PVDF (Polyvinylidene Fluoride) for superior resistance to highly corrosive materials. In addition to being an excellent tool for cooling, the Super Air Knife can solve a wide range of drying and blowoff applications. If you have an application that would be better served with one of EXAIR’s Super Air Knives, reach out to us today and get yours on order! We ship same day from stock with orders received by 3:00 pm EST, stop wasting time with ineffective cooling or blowoff methods!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD