Air Cooling Maintenance?

The time has finally come, and spring is here! The Cincinnati Reds are playing, Spring Soccer is happening early on Saturday mornings, and the FC Cincinnati Stadium is bustling here in Cincy. With that, temperatures are climbing, the grass and weeds are growing, and more and more families are out walking around and doing outdoor activities. With this, also comes warmer temps, and lots of spring allergies in the Farno household. As a dad, I have stepped into my role pretty well by trying to delay turning on the air conditioner until everyone else in the house is plotting my demise. This year, I achieved it by putting off the routine maintenance of the condensing coils.

In case you weren’t aware, here in the Midwest, where pollen runs rampant and the winds have been strong this year, it is a great idea to clean out the condensing coils on your home’s A/C system before turning it on for the year. Unfortunately, your home A/C system is not maintenance-free like the Cabinet Cooler Systems EXAIR offers; at the same time, your home needs a lot more than a few thousand BTU/hr of cooling capacity. When we first bought the home, I didn’t know this was a thing, as the home I grew up in didn’t have central air. We rocked Window A/Cs, and my parents still do. So, cleaning the outdoor unit was not part of my knowledge base. This is something I learned once the air conditioner wasn’t working, and I started to troubleshoot.

The main purpose of the condensing coils is to strip all the heat out of the refrigerant and get it to “condense” back into its liquid state to be pushed back through the orifice and continue to cool the air that is being passed over the A Coils inside the house. These coils are covered in fins that are very tightly spaced. The outside unit has a large fan that pulls the surrounding air in through the coils and exhausts the hot air up out of the top. There is no filter on that incoming ambient air, though, so all the leaves, cobwebs, pet hair, pollen, dirt, mulch, you name it, get pulled up into these fins. Over time, this starts to get a buildup, and the cooling fins will start to lose their efficiency. The fan won’t be able to pull as much air through, and eventually, the gas doesn’t get condensed, which then reduces the cooling and can cause other bigger issues. This is just like a refrigerant-based A/C panel cooler in a facility. Most of the time, they have at least a small filter on the air intake to try and reduce the contamination of the condensing coils. So I clean the A/C condenser at my house using a coil cleaning solution diluted down, a pump sprayer, and a regular garden hose.

The main thing to remember when cleaning this is that the majority of the dirt is from the air being pulled into the center by the fan. So I rinse the coils from the inside out and make sure I have free passage all the way through. The water doesn’t need to be a high-pressure rinse like an OmniStream nozzle or one of BETE’s NF Nozzles, just a simple low-pressure stream of water to get between the fins and push all contaminants as well as rinse the solution away. Remove any leaves or other unwanted debris from inside the unit and then bolt the fan and cage back down. Then let the family enjoy some cold air inside the house.

This type of maintenance is something that easily gets overlooked when looking at refrigerant-based electrical panel coolers. That is where EXAIR Cabinet Cooler Systems shine. The only filter you have to worry about is a redundant point-of-use compressed air filter that is included with the Cabinet Cooler Systems. No chemicals needed for cleaning, no water, no mess to change out a compressed air filter, just long-lasting performance. If you want to talk about how to change your control panels over to Cabinet Cooler Systems, contact an Application Engineer today.

Brian Farno, MBA – CCASS Application Engineer

BrianFarno@EXAIR.com
@EXAIR_BF

Cabinet Cooler Selection

EXAIR‘s Cabinet Coolers are a low-cost and reliable way to cool and purge your electrical panels. They incorporate our Vortex Tubes to produce cold air from compressed air. With no moving parts, our Cabinet Coolers can run maintenance free for many years.

When selecting which Cabinet Cooler is right for your application, there are a few things for you to consider:

First, is your cabinet in a hazardous location? We have HazLoc Cabinet Cooler models that are rated for UL Classified areas, including Class I Div 1, Groups A, B, C, and D; Class II Div 1, Groups E, F, and G; and Class III; as well as ATEX rated units that are approved for use in Zones 2 and 22. All of our hazardous location Cabinet Cooler Systems need to be used in conjunction with a purged and pressurized control system.

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

After this you will need to determine what NEMA integrity your enclosure requires.
We have NEMA 12(IP54) models, which are dust and oil tight. These are ideal for most industrial environments where no liquids or corrosives are present.
Our NEMA 4(IP66) options can be used inside and outside, and are splash resistant as well as dust tight and oil tight. The low-pressure relief valve will ensure the integrity of the NEMA 4 enclosure is maintained.
Finally, our NEMA 4X(IP66) option offers all the same protection as the NEMA 4X, but is constructed of stainless steel for food service and corrosive environments.

Next, you need to decide if you need continuous operation or thermostat control. The thermostat control systems are the most efficient way to operate a Cabinet Cooler. They save on compressed air by only activating the cooler only when the internal temperatures approach critical levels. The standard thermostat control systems include an adjustable thermostat factory set at 95°F. We also have our Electronic Temperature Control (ETC), which allows for precise temperature control that can be adjusted with the touch of a button.

ETC Electronic Temperature Control can be used in a wide variety of applications.

Finally, you will need to calculate the heat load to determine the cooling capacity. We have a calculator on our website that can help with this. However, if you speak to any of our Application Engineers, we can perform these calculations for you. If you would like to discuss your Cabinet Cooler application, feel free to give us a call!

Al Wooffitt
Application Engineer

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Image by Gerd Altmann from Pixabay

Hazardous Location Cooler: UL and ATEX!

EXAIR currently offers TWO styles of cabinet coolers designed and certified for classified areas. Both UL Classified and ATEX!

Hazardous locations are a tricky opponent for electrical panels and controls. To safely be in a HAZLOC, they either have to be rated for that environment or they need to be enclosed in a Cabinet that is purged and pressurized to keep any explosive gases, fumes, or dust out of the Cabinet. This is no new thing, however, as the Industrial revolution 4.0 continues to grow and progress, products are continually being added to HAZLOC areas. For example, robotic controls, analyzers, motors and switch gears now use electronic accessories to meet the needs for speed, process control and energy efficiency, which often renders the equipment unsuitable for use in hazardous locations.  While the demand for these new devices continues to grow, not all of these items are able to be made intrinsically safe. And the items that are not will need to be enclosed in a cabinet where heat will build, and you need to manage that heat load while retaining the positive pressure purge and pressurization.

HazLoc Cabinet Coolers are designed for hazardous locations and are mounted to NEMA 7, 8, and 9 enclosures.  EXAIR catalogs these Cabinet Coolers as NEMA 4 (IP66) or NEMA 4X (IP66), as mentioned above.  But their registration for UL classification is for Class I, Class II, and Class III hazardous areas, both Div 1 and Div 2.  The reason that they do not match the NEMA rating of the hazardous panels is because they require an X-type or Z-type purge system.  In combination, they will not sacrifice the integrity of the hazardous electrical panels.   

ATEX Cabinet Coolers have similar attributes to HazLoc Cabinet Coolers except this type of registration is popularly used in Europe.  These area classifications fall under the EN/IEC 60079-2 international standard for explosive zones.  It covers three zones in two hazardous areas; gas/liquid and dust.  The ATEX Cabinet Coolers can be used in Zone 2 for gas/liquid and Zone 22 for dust.  Like the HazLoc Cabinet Coolers, to keep their classification, the ATEX Cabinet Coolers require a Zone 2/22 purge system.  The ATEX terminology is as follows:  

Gas – CE EX II 3 G Ex h IIC T3 Gc

Dust – CE EX II 3 D Ex h IIIC 200oC Dc  

EXAIR offers a variety of Cabinet Coolers in stock with different cooling capacities, materials of construction, and operational locations.  We also offer them in 316SS, high temperature versions, and non-hazardous purge.  We do have a Cabinet Cooler System Sizing Guide to help determine the best product for your application or a Cabinet Cooler System Calculator to do it yourself.  For any hazardous location, we do recommend contacting us for clarification.  If you have any questions, an Application Engineer at EXAIR can assist you.    

 Jordan Shouse

Application Engineer

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UL Hazardous Locations Class 2 Division 1

Per the National Electrical Code (NEC) there are (3) classifications for areas that are defined as hazardous.  They are Class I (gases & vapors), Class II (flammable dust) & Class III (fibers). The focus of today’s Blog is on Class II locations.

Class II locations are those that are hazardous because of the presence of combustible dust. Note that the dust must be present in sufficient quantities for a fire or explosion hazard to exist. The fact that there is some combustible dust present does not mean a Class II hazardous location exists. Dust is defined as a combustible material that must exist as a finely divided solid of 420 microns (0.420 mm) or less. This will allow the dust to pass through a No. 40 sieve.  Just as in Class I, Division 1 and 2, the subdivision of Class II into Divisions 1 and 2 identifies the likelihood that there is an explosion hazard.

Division 1 locations are defined as an area where the amount of combustible dust is either suspended in the air or accumulated on surfaces in a sufficient concentration to allow for ignition.  The ignition could be caused by a failure or malfunction of the equipment in the classified area.  Group E & F dust (see chart below) is considered conductive and could penetrate into electrical equipment such as electric motors, control panels, electrical panels, etc., and cause an electrical failure.

Chart1

Group E dusts are metal dusts, such as aluminum and magnesium. In addition to being highly abrasive, and likely to cause overheating of motor bearings if it gets into them. Group E dusts are also electrically conductive and if they are allowed to enter an enclosure, can cause an electrical failure.

Chart2

Group F dusts are carbonaceous. The primary dust in this group is coal dust. Coal dust has a lower ignition temperature than those in Group E. While Group F dust has a higher thermal insulating value than the layer of Group E.  Therefore Group F requires more control of the temperature on the surfaces that the dust settles on. Group E dusts are semi-conductive, however if the voltages are 600 volts or less it is not generally considered a factor.

Chart3

Group G dusts include plastic dust, most chemical dust and food-grain dust. They are not electrically conductive. Generally, these dusts have the highest thermal insulating characteristics and the lowest ignition temperatures. Therefore, the equipment used in Group G areas must have the lowest surface temperatures to prevent ignition of a layer.

Chart4

Lastly, equipment rated for use in Classified Environments has a rating called the Temperature Code or “T-Code”.  This is the temperature or rather, temperature range that the rated device will operate normally and/or in a failed or failing state.  Consider something as common as a light fixture, electric motors, etc., as they could become hot enough to cause ignition depending on the type of dust in the area.  So be sure to check the “T-Codes” for every piece of equipment that will be used within a Classified Environment.

Chart5

When you are looking for expert advice on Hazardous Location Cabinet Coolers or safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you.

Jordan Shouse
Application Engineer

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