Finding WATTs in your electrical Panel

Picture by Isauvage – Licensed by Pixabay

In 1938 Abbot and Costello first performed their legendary routine of “Who’s on First”. If you haven’t heard this before I only have two things to say to you – 1) I’m sorry and 2) go listen to this. This is one of the funniest routines in comedic history, and you should listen to it at least once a decade. The craziest thing about this is that in 2007 there was a MLB player from the Los Angeles Dodgers that got his first MLB hit and was standing on first base. After 69 years, Abbot and Costello’s famous act came true and Hu was on first. Chin-Lung Hu that is. It was destined to happen one day, but now we have to focus on Watts on second? That’s right— Watts on second.

Photo by 2427999 and licensed by Pixabay

When we size your electrical cabinet, we ask for a current internal temperature of the cabinet. This is critical to us being able to make this calculation. You would think this is an easy request, but surprisingly we get pushback to get this number. The best way to get this number is to simply put a thermometer in the cabinet, let it sit for a few minutes and let us know the temp. The pushback is surprising as this is the most important number to know, as this is the temperature that we are cooling. If I had a nickel for every time I am asked to just guess at a number here, I wouldn’t be rich, but I could buy a soda each month. This temperature is critical for us to know, because it tells us how much cooling is needed to overtake that heat to make your cabinet safe. But, I do understand that there are times when this is not possible. And of course there are new installations where there is not a cabinet there yet… So what do we do next or “second”… You guessed it, Watts on second.

In these instances we need to find the total watts that will be used in this electrical cabinet. How do we find this? In a perfect world there should be a list of every electrical component that is on that cabinet. Each of those components should have paperwork, and or labels on them that state the total watts used. When we have this information it is as easy as adding these watts up (not much, watts up with you?)…. Sorry, that’s the dad in me.

Photo by Momentmal, licensed by pixaby

There are times when we don’t have the data, the label was destroyed etc. So how do we find the watts? Well now we have to digress back to math. Thankfully this is not a math that we have to Google to find a refresher course to remember how to do. We just have to remember the formula. Watt = AMP x VOLT x Efficiency rating (@95%). It really is that easy. As an example, if the current is 4 amps (4A) and the Voltage is 110V, you will multiply 4×110= 440W. This is why watts are sometimes called volt-amps. Next, we take into account a 95% efficiency rate for the electronics – meaning that 95% of the energy is used, and the 5% remaining is the heat that component gives off. This example will give us 440W x 5% = 22 total Watts for this component. We do this for each component and then add them all together for total watts. Volts and amps can be found in most operating manuals, and 99% of the time you can look up common amps and volts on Mr Google.

Once we have the total Watts of the cabinet cooler components, we simply multiply that by the 3.41 conversion rate to give us the BTU/HR needed for the internal heat load.

With this information we can finalize the calculations for the Cabinet Cooler by calculating the outside heat transfer. This is pretty easy, as we simply find the temp difference between the max external temp and the max desired internal temp. We take that temp difference and match it to this top secret table (right). We then multiply the BTU/HR by the square footage of the cabinet to find the external heat load.

SPOILER ALERT: To find the total heat load for your enclosure you add the internal and external heat loads together, and botta being, botta boom, Bob’s your uncle.

There are times when the sizing gets complicated with large heat loads. Please do not hesitate to reach out and talk to myself, or one of the other application engineers for this, or any other product.

Thank you for stopping by,

Brian Wages

Application Engineer

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Cover photo by JayMantri , Spoiler photo by emkanicepic, both sponsored by Pixabay

Single Acting Reciprocating Air Compressor

With all the options when it comes to air compressors, I wanted to take a deeper diver into Single acting Reciprocating compressors and see why they are so popular across all industry.

First, What is a Single acting Reciprocating air compressor, and how does it work? A single-acting compressor is a type of air compressor that uses only one end of the piston for the suction and compression. So the first stroke of the piston sucks the air inside the compressor while the air compression occurs in the second stroke.

To explore the internals a bit closer, a mechanical linkage, or connecting rod, is attached to a piston and a crankshaft.  For every rotation of a motor, the piston will move up and down.  Air is being drawn into the cylinder and then compressed.  The volume of the cylinders, the number of cylinders, and the rotations per minute will determine the amount of compressed air that can be produced.  The advantages with reciprocating compressors are that they can produce high pressure, compress different types of gases, and have a cheap and rugged design.  The disadvantages would be high vibration and noise levels as well as being oversize as compared to capacity.  (See the photo below)

Piston goes down: air draws in. Piston goes up: air is pushed out.

Let’s expand on the advantages and disadvantages a bit to see if that explains the heavy use of this style air compressor!


  • Cost! Single acting Reciprocating air compressors just cost less than other styles of air compressors!
  • They are typically easy to maintain.
  • They work great for medium duty applications
  • They require less traveling of the compressed air.


  • The piston only works in one direction at a time
  • The piston spring takes up space limiting the cylinders working stroke.
  • They are less efficient than centrifugal type compressors

No matter the type of air compressor that you use, they are very expensive to use.  Air compressors are considered to be the fourth utility within a manufacturing plant.  To help use it efficiently and safely, EXAIR offers a range of products to clean, cool, blow, clean, conserve, and convey.  This would include our Super Air Knives, Super Air Nozzles, Safety Air Guns, Cabinet Coolers, and much more.  If you want to save energy, increase safety, and cut overhead costs, you can contact an Application Engineer at EXAIR.  We will be happy to help. 

Jordan Shouse
Application Engineer

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Compressor internals image courtesy of h080Creative Commons License.

EXAIR Super Air Knife Helps Bakery Protect Sheet Pan Coating

A bakery had a process where they cleaned baking sheets after they made cakes, breads, and donuts.  The system consisted of scraping the pans with brushes prior to running them through a washing system.   The excess crust material had to be removed as it could cause problems with the washing machine.  The baking sheets had a non-stick coating to help in the baking process.  The issue that they were having was that the brushes would start to remove the non-stick coating over time, causing the pans to rust.  If you needed more iron in your diet, this would not be the proper way.  The baking sheet was 18” (457mm) wide by 36” (914mm) long.  They contacted EXAIR to see if we had a better way to clean these sheets without damaging the coating. 

EXAIR has been supplying powerful non-contact ways to clean, dry, and cool products.  For this application, I recommend the model 110218SS Super Air Knife Kit.    The kit includes an 18” (457 mm) 303SS Super Air Knife, a filter, a regulator, and a shim set.  The stainless-steel construction would protect against the harsh detergents that are used in the process.  If additional protection is required, EXAIR also provides 316SS material.  The unique feature of the Super Air Knife is that it entrains ambient air at a rate of 40:1 to deliver a hard-hitting force with a small amount of compressed air.  In addition, the filter would capture any contamination from the compressed air line to keep the surface clean.  The regulator and shim set would be used to control the amount of force required to remove the debris. 

The Super Air Knife was placed just before the washing system to remove the baked contamination.  The brush system was removed.  As a bonus, they realized that they did not need to replace the brushes quarterly, which added replacement costs and maintenance time.  Sometimes these savings are overlooked.  The setup was really easy, as they only had to run compressed air to the Super Air Knife and mount anywhere from 3” (76mm) to 12” (305mm) from the sheet instead of having to periodically adjust the brushes due to the bristles shortening.

After the installation, they were amazed at the power of the Super Air Knife.  And with the non-contact cleaning, the non-stick surface was able to last much longer without having to replace the pans.  Currently, the baking sheets are lasting twice as long as they were before they started using our product.  If you have an application, where you would like to protect the surface, EXAIR has a variety of products that can create a non-contact way to clean, dry, and cool.  An Application Engineer can assist you. This customer above could now have their cake and eat it, too.

John Ball
Application Engineer

Twitter: @EXAIR_jb

Why doesn’t my “XYZ” work?

Pic by PoseMuse licensed by Pixabay

You’ve probably been there. You install a new Super Air Knife, or an EasySwitch Wet-Dry Vac (or any other product), and it doesn’t work as we promised. Or it works great for 2-3 years, and now it’s faltering. You have trouble shot everything you know to do. You’ve changed the filters, checked for leaks on the product, checked the connections, but still it is not performing as it was, or how it is supposed to. This is usually when I get the call, and more times than not, the issue is related to the air supply.

Whether this new item isn’t performing, or an older product has been working for 2 weeks, months, or years and stops, we first need to confirm the pressure. First, we need to make sure there is a T and pressure gauge at the point of use. Although psig is only one factor of the air flow, if it is too low (or too high in some cases) that is a definite problem. Without the proper psig, our tools will not function properly. If the psig is sufficient, and our product is not operating as claimed, the next thing we check is the SCFM.

There are a few ways of finding the SCFM…one is very easy and reliable, and the other can get you close enough to realize if there is a problem or not. The easy way is by installing a Digital Flow Meter near the point of use. Although the most reliable, it is not always feasible or cost-effective to have these near every air application in your system.

Without the Flow Meter, we need to start looking for reasons why the SCFM is not there. Whether a new install or an existing one, we need to evaluate the air flow by starting with the basics. Let’s start by identifying how much air your application requires. For instance, a Super Air Knife consumes 2.9 SCFM per inch, so a 48″ Super Air Knife will use 139.2 SCFM (at standard operation), that is equivalent to a 35 HP compressor dedicated solely to this 1 product. Assuming your compressor is large enough to flow this amount of air, we need to see what other products are being utilized in the system as well. Does your overall system have enough air to run each product?

So your compressor is large enough, the next step is to look at your line size. To run 139.2 SCFM, you will need a 3/4″ line and that is if you are within 20 ft of the source (compressor). If you are 150 feet away, you will need 1 1/4″ lines, and so on. This is an issue that pops up often.

The next thing we look for is any type of restrictions on the line. Are your filter and oil separators sized properly? Were there new products / stations added to the line. Is the product itself being maintained properly? Is your Air clean and dry? Are there any other line restrictions that could be interfering with the flow?

If all of these things check out, our last course of action is to get the product back for evaluation. We will tear it apart, many times needing to destroy it to find the cause. But proudly, I must say that we rarely find a manufacturing defect, but we look hard just in case, because we want to know as well. We can usually show you the issue, and find the root cause. Our reputation and quality is the highest in the industry, and it is not something we take lightly. We want to find a defect if it exists, so that we can immediately address them, and head off any future issues.

If you have one of our products that isn’t functioning as you hoped, or just purchased one that isn’t up to par, please look at some of the items mentioned above. And as always, reach out to us and let us help f we can.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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Cover photo by gerralt / 25503 and licensed by Pixabay