Cabinet Coolers: How to Determine Heat Loads

Published on by John BallLeave a comment

As the weather starts warming up, electrical panels will start to feel the “heat”.  Freon-based coolers can be less effective in higher ambient conditions; and opening the electrical panels to have a fan blow inside creates a dangerous hazard.  The circuit industry states that for every 10oC rise above the operational temperature, the life of an electrical component is cut in half.  To reduce premature equipment failures and loss in production, it is important to keep electrical components cool.  The EXAIR Cabinet Cooler Systems are designed to do just that. 

To find the correct type and size, we need some information about your electrical panel.  EXAIR makes it easy with the Cabinet Cooler Sizing Guide.  This sheet goes over the important details to find heat loads, proper NEMA type, and options for easy installation.  With a filled-out form, we can make sure that the correct model is recommended.  First, we have to start with the surface area of the electrical panel.  From here, we can do some heat load calculations to compare it with the proper cooling capacity. 

To properly reduce the temperature internally, we need to calculate how much heat is being generated.  Heat loads come from four main areas; internal, external, fan, and solar.  From these four, we can add them together to get the total heat load.  So, on the hottest day of the hottest month, the EXAIR Cabinet Cooler System will still keep your electronics cool.  Here are some methods to find the information needed for heat load calculations.

Internal Heat Load:  The internal load is the heat generated from inside the electrical panel.  This heat is produced by the inefficiencies of electrical devices.  There are two main ways that we can figure out the internal heat load.

Step A: The simplest way is by hanging a piece of metal like a washer inside the panel for about 15 minutes.  We can get an average temperature inside.  In the sizing guide, you can mark the temperature next to “Internal temperature now”.  To calculate the heat load, we will also need the external temperature at the same time as you measured the piece of metal.  This temperature difference can determine the internal heat load per surface area of the panel.  See the chart below.

Step B:  if you know the electrical components inside that generate heat, a list can be made with volt/amp ratings, or watts.  This is very useful for new panels.  The major devices would be VFDs (Variable Frequency Drives), power supplies, UPS, transformers, thyristors, etc.  We can calculate the inefficiency of the electrical components which will give us the internal heat load. 

External Heat Load:  To keep the electronics cool on the hottest day, we will need to know the highest external temperature that the panel will see.  This can include the temperature that is near an oven.  This can be marked in the Max External Air Temperature Possible.  We can compare this to the Max Internal Air Temperature Desired.  Most electrical components are designed to operate at 95oF (35oC).   With the same chart as above, you can use the temperature difference to determine the external heat load per surface area of the panel.

Panel Fans:  To control the environment inside the electrical panels, we need to block all openings and vents.  And this will include removing panel fans.  The Cabinet Cooler System will blow dry cold air to push out the hot humid air from the electrical panel back through the Cabinet Cooler.  Since we are removing a “poor” cooling device like the panel fan, we still need to add this to the heat that is being removed.  You can either give the diameter of the fan or the flow of the fan. 

Solar Heat Load:  The solar heat is only needed if the panel is located outside without cover and exposed to sunlight.  For this type of heat load, we will need to know the color of the electrical panel.  Lighter colors will not absorb as much heat as darker colors.

EXAIR makes it easy to help correctly size the Cabinet Cooler.  We have the Cabinet Cooler Sizing Guide which you can submit to the Application Engineers to review.  And we have released the Cabinet Cooler System Calculator.  It will give you a quick recommendation to order online.  For our U.S. and Canadian customers, you will receive an AC Sensor for free, a $76.00 value, as a promotional item from now until the end of August 2025 with qualified purchases.  How can you not give them a try?  If you have any questions about Cabinet Coolers, the Sizing Guide or Calculator, you can contact an Application Engineer at EXAIR.  We will be happy to help you to keep your machines operating.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Siphon Fed Nozzles for Spraying Without a Pressurized Liquid Source

Published on by Al WooffittLeave a comment

At EXAIR we are primarily known for our compressed air products. However, we do have an extensive line of liquid spray nozzles.  These liquid nozzles fall into two main categories – Air Atomizing and Liquid Only Nozzles. We can further divide the Air Atomizing Nozzles into three more categories: Siphon Fed, External Mix, and Internal Mix. The Siphon Fed Nozzles are going to be the focus of this blog.

It is very common in spraying applications for the liquid to be pressurized. When that isn’t possible, our Siphon-fed nozzles are a great option. This type of nozzle pulls the liquid into the nozzle by creating a vacuum. This vacuum is created thanks to the special design of the air cap. As air flows through the air cap, it creates low pressure on the liquid side due to a venturi effect. These Atomizing Nozzles are capable of drawing liquid from a suction height of 36″ (91 cm) or can be fed by gravity from heights of 18″ (46 cm) or more.

Siphon Fed model

Manufactured out of 303-type stainless steel for durability and corrosion resistance, the Siphon Fed Nozzle comes in three different body sizes: 1/8 NPT, 1/4 NPT, and 1/2 NPT. This will allow for a wide range of possible application flow rates. The maximum liquid flow rate for each body size is managed by the air and liquid cap. These caps can be swapped out easily for each body size, allowing you to change the spray patterns, manage the fluid delivery rate, and minimize downtime when cleaning is needed. You can easily tweak the amount of liquid applied by adjusting the siphon height / or gravity feed height, inlet pressure, and the liquid adjusting valve stem. This way, you can fine-tune the exact fluid amount needed for your process, helping to avoid any waste.

EXAIR Siphon Fed Nozzles work with non-pressurized liquids, either siphoned (left) or gravity fed (right.)

If you would like to reduce waste even further, we also have our No-Drip option. EXAIR’s patented design helps prevent the liquid from leaking out of the Atomizing Nozzles when the compressed air supply is shut off; hence the name No-Drip! When the compressed air is switched off, a valve within the body seals off the liquid side. This is especially useful for sensitive applications, where the No-Drip feature will stop drips that might spoil the finish of your product when not activated.

If you’re looking for a solution to your liquid spray application, but want to avoid liquid pumps or pressure pots, the Siphon Fed Atomizing Nozzle may be right for you. If you would like to discuss your liquid spraying application, I’d be happy to discuss the application with you and make a reasonable recommendation backed up by our 30-Day guarantee.

Al Wooffitt
Application Engineer

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Let’s Build A Blowoff System!

Published on by Russ BowmanLeave a comment

EXAIR makes a wide variety of Intelligent Compressed Air Products that can be used for blowoff applications. The first step is to consider what size, and shape, the airflow pattern needs to be. If it’s a smooth, flat surface, our Air Knives are ideal for that. If a more directed, focused stream of air is required, we have Air Nozzles, Air Jets, and Air Amplifiers. And if it’s for statically charged debris, we can put Ionizers on Air Knives (Super Ion Air Knives), Air Nozzles (Intellistat Ion Air Nozzles), Air Jets (Gen4 Ion Air Jets) and Air Amplifiers (Gen4 Ion Air Cannons.)

If you navigate the EXAIR website to our Blowoff Kits, you’ll see that we can provide a number of our quiet, safe, and efficient Air Nozzles with Magnetic Bases and/or Stay Set Hoses for a quick & easy Blowoff System. In addition to the half dozen or so systems that are specifically called out, you can also put together your own setup that best suits your application. Here’s how:

Example: Model 1100-9412 is two Super Air Nozzles on a Dual Outlet Magnetic Base with 12″ Stay Set Hoses.

If you’d like to discuss a blowoff application – regardless of size or shape – give me a call.

Russ Bowman, CCASS

Application Engineer
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Who Wants to Save on Compressed Air?

Published on by Al WooffittLeave a comment

At EXAIR we pride ourselves on helping our customers optimize their compressed air usage. Our intelligent compressed air products are engineered to be quiet and efficient, saving you on compressed air consumption. This is just one of the six steps that we recommend in order to optimize your compressed air system.

The first step we would recommend is to measure your air consumption. If you are going to attempt to reduce air consumption in your facility, it is necessary to know what is using it. If you know the consumption of your compressed air-operated products, you can make note of this. A more comprehensive solution would be to install some of our Digital Flowmeters in branch lines in your facility. The flow data provided by this will help you narrow down the high consumption areas and processes.

The second step we would suggest is to find and fix leaks. Our Ultrasonic Leak Detector is perfect for this. According to the Compressed Air and Gas Institute, leaks should not exceed 5-10% of your system’s air supply (we would obviously want 0%, but realistically this is unachievable). However, it is not uncommon to see leaks account for over 30% of many facilities’ compressed air supply being lost through leakage. That’s a potential for a 25% gain in compressed air supply!

The third step would be to upgrade your blowoff, cooling and drying operations using engineered compressed air products. All of EXAIR’s products, like our Super Air Knives, or Super Air Nozzles, are designed with efficiency in mind. Upgrading to an efficient EXAIR product is going to reduce your consumption, sometimes dramatically so!

The fourth step is to turn off your compressed air when not in use. This may sound obvious, but it is not uncommon for compressed air products to be left running continuously. We offer many solutions here, from a simple ball valve (found in many of our Drum Vac Kits), to a solenoid valve (found in our Cabinet Cooler Systems), to our Electronic Flow Controllers – combining a solenoid valve and photoelectric sensor.

The fifth step would be to use intermediate storage near the point of use. If you are controlling your compressed air usage through the use of valves and controls, then your consumption won’t be constant. This fluctuation in demand can be evened out with the use of secondary storage, like our Model 9500-60 Receiver Tank. This will ensure you have the volume and pressure when and where you need it.

Finally, our sixth step is to control the operating pressure. More specifically, to reduce the pressure to the minimum required to get the job done. Simply installing a pressure regulator at the point of use will lead to big savings.

If you would like to start optimizing your compressed air system, then give me a call!

Al Wooffitt
Application Engineer

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