Understanding your Cabinet Cooling Investment

You can make a better decision choosing your cabinet cooling product by understanding the total cost of your investment and the operating cost associated with each style. Today we will compare EXAIR Cabinet Cooler systems and a refrigerant based enclosure air conditioning system.

How will EXAIR’s Cabinet Cooler system benefit you? I will help you understand your investment, installation, maintenance and operating costs for both EXAIR Cabinet Coolers verses a refrigerant based conditioner. The importance of understanding these costs will not only help you realize the return on your investment but will also give you the confidence knowing you made the best decision for you and your company. We will compare EXAIR’s model 4325 (NEMA 12) with a 1700 BTU capacity to a similar coolant based air conditioning unit.

The initial investment for the EXAIR model 4325, 1700 Btu/hr. Cabinet Cooler system at 2021 list pricing is $809 and will have an estimated life of 20 years ($40.45/yr). The initial cost for a refrigerant based A/C with similar Btu/hr is $3777 and an estimated life of 5 years ($751.58/yr). EXAIR’s Cabinet Cooler runs on compressed air and has no moving parts which provides a long product life . It is built for industrial, dirty, extreme temperature, heavy duty and remote locations.

Installation of the EXAIR Cabinet Cooler when installed according to manufacturers recommendation will take approximately 1 hour (estimating $65/hr) while the enclosure a/c will take up to 3 hours or more. There is no worrying about what position it was on the shipping truck, no time to allow the oil to drain back into the refrigerant compressor and no huge window to cut out of your enclosure to mount within. Again the edge goes to EXAIR Cabinet Coolers with less hassle and downtime. If we use that same operating lifetime the Cabinet Cooler system will require $3.25/yr and the refrigerant unit will require $39/yr for installation.

As mentioned earlier that EXAIR Cabinet Coolers do not have moving parts thus reducing or practically eliminating any maintenance or downtime. The refrigerant cooler will average 4 hours of downtime for cleaning and checking for refrigerant leaks. You will also experience downtime to replace filters and refill refrigerants when required. There will be drain lines to maintain for the condensate that will accumulate. EXAIR wins again having no downtime or costs for replacement parts. A refrigerant unit can require 4 hours per year of maintenance to provide its full five years of usefulness. Again using $65/hr there are zero dollars per year in Cabinet Cooler system maintenance compared to $260/yr for the refrigerant unit.

If we assume that the systems run an average of 5 hours per day, 5 days per week and 9 months per year we can calculate the cost of operating each style of cooling device. We know that it costs $0.025/1000 cu. ft of air. When put into our equation it shows that the EXAIR Cabinet Cooler system has an annual operating cost of $338. The coolant based a/c unit operated on electric at a rate of $0.0955/KWH for an annual operating cost of $56.38 giving the edge to this unit.

The total cost of your investment, installation, maintenance and operating costs for the EXAIR Cabinet Cooler is $382 per year while the coolant based a/c is $1106.96 per year giving a fast return on investment for the EXAIR 4325 Cabinet Cooler system and a very long period of keeping your electronics protected and running effectively.

EXAIR Cabinet Coolers are a low cost, reliable way to cool and purge electronic control panels. Not only is the EXAIR product more economical to purchase, maintain and install but they also provide a longer life as they incorporate a vortex tube to produce cold air. The EXAIR system also maintains NEMA 12, NEMA 4 and NEMA 4X panel integrity and are UL Listed and CE certified by independent laboratories.

EXAIR Application Engineers are ready to answer all your questions and help you determine the correct cabinet cooler size specifically for your needs.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

 Categories: Cabinet Coolers

 

The Basics of Calculating Heat Load for Cooling Electrical Cabinets

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.

How the EXAIR Cabinet Cooler System Works


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.

From right to left: Small NEMA 12, Large NEMA 12, Large NEMA 4X

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
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Battling Heat Transfer

If you haven’t read many of my blogs then this may be a surprise. I like to use videos to embellish the typed word. I find this is an effective way and often gives better understanding when available.  Today’s discussion is nothing short of benefiting from a video.

We’ve shared before that there are three types of heat transfer, more if you go into sub-categories of each. These types are Convection,  Conduction, and Radiation. If you want a better understanding of those, feel free to check out Russ Bowman’s blog here.  Thanks to the US Navy’s nuclear power school, he is definitely one of the heat transfer experts at EXAIR.  If you are a visual learner like myself, check out the video below.

The Application Engineering team at EXAIR handles any call where customers may not understand what EXAIR product is best suited for their application. A good number of these applications revolve around cooling down a part, area, electrical cabinet, or preventing heat from entering those areas.  Understanding what type of heat transfer we are going to be combating is often helpful for us to best select an engineered solution for your needs.

Other variables that are helpful to know are:

Part / cabinet dimensions
Material of construction
External ambient temperature
If a cabinet, the internal air temperature
Maximum ambient temperature
Desired temperature
Amount of time available
Area to work with / installation area

Understanding several of these variables will often help us determine if we need to look more towards a spot cooler that is based on the vortex tube or if we can use the entrained ambient air to help mitigate the heat transfer you are seeing.

If you would like to discuss cooling your part, electrical cabinet, or processes, EXAIR is available. Or if you want help trying to determine the best product for your process contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Video Source: Heat Transfer: Crash Course Engineering #14, Aug 23, 2018 – via CrashCourse – Youtube – https://www.youtube.com/watch?v=YK7G6l_K6sA

Undersized Regulators Create Performance Problems with Compressed Air

“I have a Cabinet Cooler installed on my panel but it isn’t getting the temperature down cold enough. Can you quote me for a duplicate system to install on this panel?” This was a recent inquiry from a customer regarding an electrical enclosure that they had installed in their plant. The Cabinet Cooler was producing cold air, but not enough to keep the cabinet at their desired temperature. It would seem logical that they need additional capacity, right? While that could be the case, in this instance it most definitely was not.

When we get questions like this, we first want to take a closer look at the current installation. The cooling capacity for each system is published in our catalog. BUT, in order to rate a cooling capacity for any type of cooling system, some assumptions must be made. All Cabinet Coolers are specified with 70°F compressed air fed to the Cabinet Cooler at a pressure of 100 PSIG. In addition, each cooler has a specified volume of air that it must utilize in order to produce that rated cooling capacity. If any one of those parameters change, so does the overall cooling power.

In this particular case, the customer had installed a non-EXAIR pressure regulator just upstream of the cooler. Upon looking at the specifications for this regulator, it was found that the overall volume of air it can deliver was just 10% of the overall volume needed to produce the rated 1700 Btu/hr. They didn’t need another Cabinet Cooler System, they just needed to remove that restriction! Upon learning that it needed 100 PSIG, they removed the regulator and supplied full line pressure. No more heat alarms for that shift!

CC undersized valve

Rather than purchasing and installing an unnecessary system, they were able to get back up and running just by removing the problem upstream. At EXAIR, we want to make sure that you’re getting the most out of our products. Just because you call and inquire about a new purchase doesn’t necessarily mean that you need it. We’re here to help you determine if something is afoul with the current setup and make sure you have all of the knowledge necessary to rectify it.

We’re right in the middle of summer, and boy is it hot out there. If you have panels that are overheating and creating problems for you in your processes, give us a call. With Cabinet Cooler Systems ready to ship same day from stock (with properly sized regulators) you can have it fixed by tomorrow.

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