Cooling control cabinet

[Davebones]

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 ?

 

[bwat]

Are you familiar with the vortex coolers? Uses compressed air.

There are a number of makers. Here's one.

Vortex Coolers

hoffman.nvent.com

 

[EC Dan]

I've installed Stratus air-to-air heat exchangers on a couple panels. There is no contact between the inside and outside air, but these can only limit the temperature rise above ambient. You'll need to do thermal calculations to size a unit appropriately.

I also looked at those vortex coolers but they require a huge amount of air, more than our plant compressed air supply could deliver without significant pressure drop.

 

[petersonra]

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.

 

[Burkut]

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 6000 BTU.

https://www.thermoelectric.com/air-conditioners/

 

[Jraef]

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.

 

[rafaelrobertson]

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.

 

[petersonra]

If you are in a humid area you will have to deal with condensate draining, another detail that is often missed.

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.

 

[petersonra]

I have designed control cabinets with no cooling, just stirring fan, filtered air blown in from surrounding area, filtered air brought in via duct from outside the building, a/c, heat exchangers, cold plates, vortex.

Never used the thermoelectric though. Just too crazy expensive.

 

[Jraef]

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.

 

[DooWop]

The cabinet that runs hot, humidity shouldn't be an issue.
Most of these cabinets can be cooled with a muffin fan. Source the supply air from a conditioned space.
Exhaust to where ever it's convenient.
As long as mechanical cooling isn't needed. Most controls can be cooled with room air.

 

[LarryFine]

I've seen what appear to be simple window A/C units installed in cabinets.

 

[Shaneyj]

I just installed a few thermoelectric coolers in some control boxes headed to the oil patch. Boxes were smallish, 16x14x8. I used a cooler from automation direct for $650.
Definitely the most dollars per btu I’ve come across.
They’re pretty neat though.


Sent from my iPhone using Tapatalk

 

[DooWop]

What's missing from the OP is the load. With out the numbers it's a wild a$$ guess.
But as long as the rise isn't crazy, most cooling can be done with air. It's important to remember that
what makes us uncomfortable might not be a biggie with controls but I have seen where some are more sensitive
than others.
If the OP could measure the temperature rise the load could be determined

 

[paulengr]

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 3500 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.

 

[SceneryDriver]

I've used AC units from Iceqube with great success:

Electrical Enclosures and Climate Control

Manufacturer of enclosure cooling for NEMA type electronic enclosures, Ice Qube keeps electronics cool with air conditioners, heat exchangers and filtered fans.

www.iceqube.com

I have several of them on the top decks of cruise ships (outdoors); marine environment with salt spray and tropical temps. I ordered the 316SS version with the corrosion protection package and they've been solid performers for almost five years so far. Iceqube is my first choice for control cabinet climate control.


SceneryDriver

 

[retirede]

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 3500 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.

 

[tom baker]

The cabinet that runs hot, humidity shouldn't be an issue.
Most of these cabinets can be cooled with a muffin fan. Source the supply air from a conditioned space.
Exhaust to where ever it's convenient.
As long as mechanical cooling isn't needed. Most controls can be cooled with room air.

For cabinet cooling an air supply fan works better with denser outside air, than exhausting hot less dense air

 

[petersonra]

For cabinet cooling an air supply fan works better with denser outside air, than exhausting hot less dense air

Most fans used for this purpose cool the fan motor with the air going past it. You want to use cooler air to cool the fan motor as opposed to warmer air so the fan motor will last longer.

 

[rafaelrobertson]

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.

yes, you are right. i totally agree with you.