For the longest time we have been using this form on EXAIR.com to get the information we needed to manually calculate the internal and external heat loads and ultimately make a recommendation on which Cabinet Cooler System would be best for that application! Typically it would take thirty minuets to an hour to get a email back from a application Engineer!
While the manual Cabinet Cooler Sizing Guide worked great (and we will still reply within 24 hours), we have been racking our heads over here to better that process and get you a solution faster than ever! Now you type in your information and you have a recommendation and a link to that product on the website where you can learn more or place an order! So you can go from form to order in less than 5 Minuets!!!! Check it Out HERE!!
By providing certain information like size of the enclosure, NEMA rating needed, and environmental conditions, this new calculator will sort through our large selection of ready-to-ship Cabinet Cooler® Systems and provide instant feedback on the best model number for any applicable electrical enclosure. Taking the guess work out of the equation, EXAIR’s Calculator ensures the customer that they can be confident in selecting the correct product for their unique specifications. You can even Print the form for your records!
EXAIR’s complete line of Cabinet Cooler systems include 120V AC, 240V AC and 24V DC thermostat voltage, continuous operation, type 316 stainless steel and high temperature models – all of which are selectable with the new calculator. Find this new tool on the website EXAIR.com, in the Knowledge Base Calculators, along with many other resources, such as the CAD Library and Application Database, which also help customers choose a perfect solution. Cabinet Cooler systems start at $534. https://www.exair.com/knowledgebase/calculator-library/cabinet-cooler-system-calculator.html
Is your electrical cabinet overheating and causing expensive shut downs? As spring and summer approach, did your enclosures have seasonal overheating problems last year? Is your electrical cabinets AC Unit failing and breaking down? Then it may be time to consider EXAIR Cabinet Coolers Systems. These systems are compressed air powered cooling units designed to keep your cabinet cool in hot environments. Major benefits include no moving parts to wear out, UL listed to maintain the NEMA integrity of your enclosure (also CE compliant), they are simple and quick to install and they reliably turn on and off as needed (perfect for solving seasonal overheating).
Just one question then; how do you pick which Cabinet Cooler is best for your application? It’s time to bust out ye ole trusty calculator and crunch some numbers. Keep in mind that the following calculations use baselines of an Inlet air pressure of 100 psig (6.9 bar), compressed air temperature of 70F (22C), and a desired internal temp of 95F (35C). Changes in these values will change the outcome, but rest assured a Cabinet Cooler system will generally operate just fine with changes to these baselines.
Before we dig right into the math, keep in mind you can submit the following parameters to EXAIR and we will do the math for you. You can use our online Cabinet Cooler Sizing Guide and receive a recommendation within 24 hours.
There are two areas where we want to find the amount of heat that is being generated in the environment; this would be the internal heat and the external heat. First, calculate the square feet exposed to the air while ignoring the top. This is just a simple surface are calculation that ignores one side.
(Height x Width x 2) + (Height x Depth x 2) + (Depth x Width) = Surface Area Exposed
Next, determine the maximum temperature differential between the maximum surrounding temperature (max external temp) and the desired Internal temperature. Majority of cases the industrial standard for optimal operation of electronics will work, this value is 95F (35C).
Max External Temp – Max Internal Temp Desired = Delta T of External Temp
Now that we have the difference between how hot the outside can get and the max, we want the inside to be, we can look at the Temperature Conversion Table which is below and also provided in EXAIR’s Cabinet Cooler System catalog section for you. If your Temperature Differential falls between two values on the table simply plug the values into the interpolation formula.
Once you have the conversion factor for either Btu/hr/ft2, multiply the Surface Area Exposed by the conversion factor to get the amount of heat being generated for the max external temperature. Keep this value as it will be used later.
Surface Area Exposed x Conversion Factor = External Heat Load
Now we will be looking at the heat generated by the internal components. If you already know the entire Watts lost for the internal components simply take the total sum and multiply by the conversion factor to get the heat generated. This conversion factor will be 3.41 which converts Watts to Btu/hr. If you do not know your watts lost simply use the current external temperature and the current internal temperature to find out. Calculating the Internal Heat Load is the same process as calculating your External Heat Load just using different numbers. Don’t forget if the value for your Delta T does not fall on the Temperature conversion chart use simple Interpolation.
Current Internal Temp – Current External Temp = Delta T of Internal Temperature Surface Area Exposed x Conversion Factor = Internal Heat Load
Having determined both the Internal Heat Load and the External Heat Load simply add them together to get your Total Heat Load. At This point if fans are present or solar loading is present add in those cooling and heating values as well. Now, with the Total Heat Load match the value to the closet cooling capacity in the NEMA rating and kit that you want. If the external temperature is between 125F to 200F you will be looking at our High Temperature models denoted by an “HT” at the start of the part number.
If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.
Cody Biehle Application Engineer EXAIR Corporation Visit us on the Web Follow me on Twitter Like us on Facebook
With the hot summer months upon us, elevated temperatures can cause shutdowns and interference with electrical systems. For every 10 deg. C rise above the operational temperature, the life of an electrical component is cut in half. With Freon-based coolers, higher ambient conditions make them less effective; and opening the electrical panel to have a fan blow inside creates a dangerous hazard as well as blowing hot, humid, dirty air inside the panel. To reduce loss in production and premature equipment failures, it is important to keep the electrical mechanisms 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. The EXAIR Cabinet Coolers range from 275 BTU/hr (69 Kcal/hr) to 5,600 BTU/hr (1,411 Kcal/hr) in cooling capacities. And with the filled-out form, we can make sure that the correct model is recommended. In this blog, I will cover a section of the sizing guide, the heat loads.
To properly cool, we need to calculate how much heat is being generated. Heat loads come from three main areas; internal, external and solar. 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 from the inefficiencies of the electrical devices. There are three ways that we can figure 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. The best place for the washer will be toward the top half of the panel, as heat rises. In the sizing guide, you can mark the temperature next to “Internal temperature now”.
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 VFD (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.
Step C: If you know the amount of power going into the panel, and the amount of power leaving the panel, the difference will tell us the amount of power that remains for the electrical components. We can take a 5% average as the heat loss.
External Heat Load: The external heat load is attributed to the environment surrounding the electrical panels. This is a standard temperature reading in oF or oC. Only with Step A above, we will need to know the external temperature at the time that you measured the internal heat measurement. This needs to be placed in “External Temperature Now”. The difference to the internal temperature will give us the heat load per square feet (square meter). Reference chart below. We will also need to know the highest external temperature that the panel will see. So, during the hottest day of the hottest month, the EXAIR Cabinet Cooler will still be able to keep your electronics cool and operational.
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.
Because there is so much information that is critical for proper sizing, the Cabinet Cooler Sizing Guide is the best tool to use to facilitate the calculations. I gave examples above to find different ways to get the proper information. Electrical shutdowns are expensive and annoying. If you have interruptions from high internal temperatures, EXAIR Cabinet Coolers are a great solution. They can be installed quickly and easily. With no moving parts or costly preventative maintenance needed, they can run for decades in keeping your electronics cool. For our U.S. and Canadian customers, you will receive an AC Sensor for free, a $58.00 value, as a promotional item from now until the end of August 2020 with qualified purchases. How can you not give them a try? If you have any questions about Cabinet Coolers or the Sizing Guide, you can contact an Application Engineer at EXAIR. We will be happy to help.
Warmer temperatures are quickly approaching, which may seem like a welcome change for personal reasons, but in a processing line, the increased temperatures can wreak havoc on sensitive components found in an electrical control panel.
EXAIR Corporation will be hosting a FREE webinar titled “Intelligent Solutions for Electrical Enclosure Cooling” on May 23, 2018 at 2:00 PM EDT.
By attending this interactive session, you will learn the difference between the 3 most common NEMA ratings for electrical control panels found in an industrial setting, NEMA Type 12, 4 and 4X. We’ll provide examples of traditional, yet unreliable, methods of cooling and the concerns associated with using these types of devices.
Next we will explain how ignoring heat related issues can cause machines to shut down due to failed electrical components, resulting in lost production and increased maintenance costs, negatively affecting a company’s bottom line.
In closing, we’ll show how using an engineered, compressed air operated solution can reduce downtime by providing a low cost, maintenance-free way to cool and purge control panels with no moving parts.