The Cabinet Cooling System Choice: How to Ensure Success

The best time to consider cabinet cooling system options is during the cabinet design stage. Crucial decisions that affect heat load and methods of cooling can then be made in conjunction with equipment selection and cabinet layout. It’s also the correct time to evaluate the implications of the cabinet’s location and to identify environmental constraints.

If you are looking for more details, kindly visit Lingji Jingke.

The careful evaluation of all these factors helps ensure the successful choice of the cabinet cooling system.

Cabinet Size and Shape Affects Cooling Design

The type of cooling solution has a bearing on equipment layout. With fan cooling, equipment that generates heat should be placed near the bottom where the air is cooler. But if a side-mounted cooling solution is used, hot equipment should be placed next to the cool air inlet.

Consequently a wide, short cabinet may be better for fan cooling, whereas a tall and narrow cabinet is more suited to side-mounted cooling. Also, take into consideration that the greater surface area of a large enclosure will have better heat conduction properties than a small enclosure.

Assess the Heat Load

Calculate the cabinet heat load by adding together the heat generated by each piece of equipment. To calculate the heat generated by power conversion equipment like variable frequency drives, inverters, rectifiers and transformers, subtract the device efficiency from one (1-Efficiency) and multiply this by the input current times the input voltage. You can reduce the total heat load considerably by choosing efficient power conversion equipment.

If the cabinet is outdoors, solar radiation will contribute towards the total heat load. Try to minimize this by shielding the cabinet.

Identify Ambient Conditions

Establish the ambient conditions at the location where the cabinet is to be installed. Key considerations include:

If you want to learn more, please visit our website cabinet air conditioner.

• Maximum ambient temperature: Establish the highest ambient temperature recorded for that location by consulting local climate data, if outdoors. If indoors, identify heat sources and, if possible, measure the air temperature.
• Dust and dirt: Is the location excessively dusty?
• Risk of corrosion: Are corrosive vapors, including salt spray, or chemicals present?
• Water: Will the enclosure be sprayed, washed down or subject to excessive splashing?
• Humidity and dew point: In humid locations, condensation may occur inside the enclosure when the temperature falls below the dew point; check to see if this is a possibility.

These factors will largely determine what cooling options are viable and help establish the required NEMA rating of the cabinet.

Select the Enclosure Temperature

Choose a maximum enclosure temperature that’s lower than that of the most sensitive equipment. It’s wise to adopt a conservative approach and increase the margin of safety by selecting an enclosure temperature that’s several degrees below the maximum temperature; 95 °F is a good choice for most electrical equipment.

Enclosure Temperature Management Calculation

It’s now possible to calculate the cabinet cooling system capacity using the information that’s been collected. Preferably use an online Enclosure Temperature Management (ETM) calculator as this method of calculation has proven to be simpler and more accurate than manual calculations. If you are unsure which is the best cooling method, repeat the calculation for all three cooling options; Air Conditioners, Heat Exchangers and Filtered Fans.

Cabinet Cooling System Choices

After identifying the viable cooling solutions, the next step is to decide between open loop and closed loop cooling:

Open loop cooling:

Open loop cooling draws outside air into the enclosure using filtered fans  and is most suitable for NEMA Type 1 and Type 3 ventilated enclosures that are not subject to excessive dust, heavy splashing or water spray. An optional 3R Fan Shroud Kit can be specified for outdoor use. Always bear in mind that fans only remove heat and cannot cool the enclosure below the ambient air temperature.

Closed loop cooling:

With closed loop cooling, the enclosure cooling circuit is completely separate from the external air cooled circuit. The two options are air to air heat exchangers and enclosure air conditioners. An air to air heat exchanger is a good choice for moderate heat loads and its only limitation is that, like cooling fans, it cannot cool below the ambient air temperature. If the ambient temperature is higher than the required enclosure temperature or the heat load too large, an enclosure air conditioner is the best choice. Another benefit of an air conditioner is that it can be equipped with an optional heater package to prevent internal condensation in cool, damp weather. Air conditioners and air to air heat exchangers can be supplied for NEMA Type 12, 4 or 4X enclosures to suit all environmental requirements. Heavy-duty filters are also available to provide added protection to air conditioner condensers in extremely dusty conditions.

The Recipe for Success

Most enclosure cooling problems can be avoided by incorporating the cabinet cooling system design into the initial design phase. Benefits include the ability to select the best cooling option and the optimum internal layout; these can be drawn up before the detailed panel arrangement is completed to suit cooling airflow requirements and ensure a uniform internal temperature profile. 

Contact us to discuss your requirements of heat exchanger manufacturers. Our experienced sales team can help you identify the options that best suit your needs.

It appears like the suggestion to look at vortex coolers might make sense for your application.

HOWEVER, be aware they have some issues that can be problematic,

1. A lot of air supplies have oil or water in them. You will want to have some kind of device at the cabinet to remove the oil and water from the air before it enters the cabinet. Otherwise the inside of the cabinet will become slimy. be aware of where the air intake for the compressor comes from as well.

2. Compressed air is very expensive. Make sure you include a thermostat and solenoid valve so the air is only on when needed.

Cabinet air conditioners do not bring outside air into the cabinet being cooled, but do require some ongoing maintenance. They are available in type 4X design that may be suitable for your environment.

Here is a brand we use regularly. Figure out how many BTUs/hour you need and get one with that capacity.



There are also air to air heat exchangers that don't bring in any outside air to the cabinet. They can work OK if you want to reduce the energy costs of running the cooling device and the ambient temperature works out. Obviously, if the temperature outside the cabinet is 100 deg F, you will not be able to cool the inside below 100 Deg F.

One other thing to consider. You might be able to get by with just adding a stirring fan inside the cabinet. Moving the air around inside the cabinet gets rid of hot spots and promotes better cooling through the walls of the enclosure. This can work well if the ambient temperature outside the cabinet makes this option practical.

The important thing is to run the numbers and not wing it. Most of the time industrial control equipment can readily handle at least 40 deg C. It may be a little warm but the equipment will not care much.

You could also get a cooling plate that works with chilled water if you have chilled water available. pretty cost effective.

New control cabinet roughly 6ft x 6ft x 2ft deep is getting hot inside . We want to add a cooling system to the cabinet due to the heat , humidity in the area , and electronics inside the cabinet . We have a concern about just getting any type of cooling system as this is in a anodizing area with all kind of different tanks . We have ventilation in the room but this doesn't exhaust 100% of the fumes . Can anyone recommend cooling system that would not pull in fumes from outside the cabinet to cool the inside ?

What do you have inside the enclosure and how much heat is generated (in terms of watts) in the enclosure?
What is the worst-case temperature outside of the enclosure?
What is the temperature that you want to maintain the enclosure at?

Please take a look at the below link, closed-loop thermoelectric panel coolers with cooling capacity ranges of 130 BTU to BTU.

https://www.thermoelectric.com/air-conditioners/ I once did a vortex cooler system for some enclosures with PLCs inside that were above "pot lines" in an aluminum smelter, so VERY hot ambient air. For a 24x20x12 enclosure, the vortex cooler required what turned out to be 10HP worth of compressed air! They had no other viable choice so we had to use that, but as mentioned, that little detail is often overlooked when evaluating them.

I too like the Thermal Edge air conditioners, I've used them several times. But really most of the industrial brands like McLean (Hoffman), Rittal, Ice Cube etc. are all decent products. If you are in a humid area you will have to deal with condensate draining, another detail that is often missed.

The basic rule-of-thumb on heat exchangers is that the maximum ambient must be at least 10deg C LOWER than the maximum internal temperature. So for example if you must maintain 40C (104F) max. inside of the box, you must have NO HIGHER than 30C (86F) ambient, otherwise it will not work.

I really like the idea of Thermo-Electric (Peltier effect) cooling, but ho boy, the pricing (last time I checked) was a non-starter compared to conventional industrial air conditioners.

I once did a vortex cooler system for some enclosures with PLCs inside that were above "pot lines" in an aluminum smelter, so VERY hot ambient air. For a 24x20x12 enclosure, the vortex cooler required what turned out to be 10HP worth of compressed air! They had no other viable choice so we had to use that, but as mentioned, that little detail is often overlooked when evaluating them.

I too like the Thermal Edge air conditioners, I've used them several times. But really most of the industrial brands like McLean (Hoffman), Rittal, Ice Cube etc. are all decent products. If you are in a humid area you will have to deal with condensate draining, another detail that is often missed.

The basic rule-of-thumb on heat exchangers is that the maximum ambient must be at least 10deg C LOWER than the maximum internal temperature. So for example if you must maintain 40C (104F) max. inside of the box, you must have NO HIGHER than 30C (86F) ambient, otherwise it will not work.

I really like the idea of Thermo-Electric (Peltier effect) cooling, but ho boy, the pricing (last time I checked) was a non-starter compared to conventional industrial air conditioners.

Well, I guess This could fall in the Show Your Stuff Section. However, It is a bit off-topic. I have seen electrical cabinets that were either open loop cooling or closed loop cooling. All my builds to date have been open loop cooling with filter screens. Most Commercial machines however are closed loop. That said has anyone built electrical cabinets with closed loop cooling? If so did it make it more maintenance-free? Or did it become more trouble than it was worth? Also, I am talking about any air-to-air or liquid-to-air type heat exchangers. I know that some commercial types have used active refrigeration systems. That said I don't use my equipment when it feels like 110 degrees F. in my garage.

There should not be much condensate unless the cabinet doors are open. Once the little bit of humidity inside the cabinet is gone there is not much going to find it's way back in from the outside as it is pretty well sealed up.

I was referring to the condensate on the outside. Most use an evaporator, but in really humid areas (like Florida) I have seen those not be able to keep up and there is a constant pool of water on the floor under the A/C unit, which in some industrial areas is a real hazard.

Years ago when Hoffman used to give out those free CDs with the cooling calculation program on it, I would use it to keep increasing the enclosure size until it told me I no longer needed an A/C unit. I was in the Pacific NW at that time though, so I could base it on cooler ambient than I would be able to use down here now in California. But sometimes it would get ridiculous; I once had to put a 75HP VFD in a NEMA 4 sealed box, where they would not consider using an A/C. The box ended up being 120" wide, 90" tall, 24" deep and had to be in 100% shade at all times, so they had to build a lean-to for it. The A/C unit would have been cheaper. Before doing cooling, first consider alternatives. Three huge heat sources are transformers, drives, and DC power supplies. The first step is get the heat out of the cabinet. Many VFDs are offered in flange mount. So with a simple trim panel the heat sink (usually NEMA 4X aluminum) sticks out the back. You can buy epoxy encapsulated transformers that are nonvented. Just put the whole thing outside the panel with conduit connections. Or just separate things. You have a huge panel. Put say a fused disconnect and the DC power supply outside the cabinet in its own smaller and much more easily cooled cabinet. Plus it often moves arc flash out of the cabinet.

Also if you are outside in sun make sure you put up an awning or attach heat shields first. This also applies inside. Aluminum has roughly an emissivity of 0.05. It absorbs relatively little heat. So simply placing a layer of cheap “tin” siding on 1” standoffs in front of a heat source blocks something like 95% of radiated heat. On kilns we can reduce 800 degrees down to 100.

Also if you are still using CVTs, why??? Simple Islatrol filters and/or electronic power conditioners do everything the CVT does without all the disadvantages. A CVT is essentially a giant heavy panel heater. It runs a transformer in saturation so that it puts out square waves then uses a heavy resonant filter to pick the 50/60 Hz out. This is clearly highly inefficient and generates tons if heat.

I prefer thermoelectric coolers when it makes sense. The pluses are they are sealed…no exchange of air between outside and inside. They actually cool. And other than the two fans there are zero moving parts. They last up to ten years in really bad environments. Those are the good points. The negatives are they don’t scale up well so W of cooling is a realistic upper limit. They aren’t as efficient as air conditioners/heat pumps.

Next up is the stratus air to air heat exchangers. As long as ambient is ok which it usually is these are simple and work incredibly well at very low power.

I would consider true air conditioners/heat pumps last. Expensive, high power, and they don’t work long. Bard, Hoffman, many others. I’ve tried them all. They all suck. But if you need a lot of cooling and fans and the above doesn’t cut it, this is your best choice.

As with others, the biggest advantage of vortex cookers is they are cheap. It costs roughly 8 watts to make 1 watt of cooling. They spew oil all over everything. And they are usually too tiny to be effective.

Before doing cooling, first consider alternatives. Three huge heat sources are transformers, drives, and DC power supplies. The first step is get the heat out of the cabinet. Many VFDs are offered in flange mount. So with a simple trim panel the heat sink (usually NEMA 4X aluminum) sticks out the back. You can buy epoxy encapsulated transformers that are nonvented. Just put the whole thing outside the panel with conduit connections. Or just separate things. You have a huge panel. Put say a fused disconnect and the DC power supply outside the cabinet in its own smaller and much more easily cooled cabinet. Plus it often moves arc flash out of the cabinet.

Also if you are outside in sun make sure you put up an awning or attach heat shields first. This also applies inside. Aluminum has roughly an emissivity of 0.05. It absorbs relatively little heat. So simply placing a layer of cheap “tin” siding on 1” standoffs in front of a heat source blocks something like 95% of radiated heat. On kilns we can reduce 800 degrees down to 100.

Also if you are still using CVTs, why??? Simple Islatrol filters and/or electronic power conditioners do everything the CVT does without all the disadvantages. A CVT is essentially a giant heavy panel heater. It runs a transformer in saturation so that it puts out square waves then uses a heavy resonant filter to pick the 50/60 Hz out. This is clearly highly inefficient and generates tons if heat.

I prefer thermoelectric coolers when it makes sense. The pluses are they are sealed…no exchange of air between outside and inside. They actually cool. And other than the two fans there are zero moving parts. They last up to ten years in really bad environments. Those are the good points. The negatives are they don’t scale up well so W of cooling is a realistic upper limit. They aren’t as efficient as air conditioners/heat pumps.

Next up is the stratus air to air heat exchangers. As long as ambient is ok which it usually is these are simple and work incredibly well at very low power.

I would consider true air conditioners/heat pumps last. Expensive, high power, and they don’t work long. Bard, Hoffman, many others. I’ve tried them all. They all suck. But if you need a lot of cooling and fans and the above doesn’t cut it, this is your best choice.

As with others, the biggest advantage of vortex cookers is they are cheap. It costs roughly 8 watts to make 1 watt of cooling. They spew oil all over everything. And they are usually too tiny to be effective.

Back in the day, we used Kooltronic AC units in an industrial setting without issues. The key was to throw away the supplied washable filters and refit with disposable. Our plant was really dirty so we had someone assigned to go through the plant and replace the filters every Monday morning.

The oil discharge problem with vortex is largely due to a neglected or improperly designed plant air system.