Enclosure Cooling

Who makes the best air power coolers? I have been looking at exair brand http://www.exair.com/en-us/Pages/default.aspx as well as vortec http://www.vortec.com/vortex_ac.php

I just wanted to get some opinions from people that use these.

Are they typicaly better than an ac unit for a enclosure?

Our ac units do not perform that well because the plant is so hot also.

ok the first thing you have to be aware of for air power coolers is because they run on the plants compressed air- the ******t air temp has an effect on their cooling ability - i think the specs they give on the site (esply for the vortec models) are based on the assumpition that the ******t air temp is like 75-80F - the hotter it is the more that you have to derate the cooling ability

I'm somewhat familar with them because i looked into using them for a packageing line my company was qouting that was going to be installed in the caribean - so heat was definitly a concern.

I think it really comes down to a)how hot is your ******t air? b) whats the size of ur enclosure c) how many BTU's of cooling are you aiming for? (i think cooling is measured in BTU's if not forgive me!)

ambi-ent lol why does this site censor ambi-ent?

The popular spam drug names a-m-b-i-e-n and c-i-a-l-i-s are both blocked even when embedded in other words.

<warning - I work for a Rittal Distributor>

Rittal makes a piece of software that lets you calculate the required cooling for a given enclosure.

This link:
http://www.rittal-corp.com/software/

Then click on the software tab.

It has Rittal box sized in the database but you can select one of similar size for any manufacturer. But physics is physics so when you put in good data for the heat generated inside, duty cycle and outside temp, you will know how much cooling you need. Of course, the software makes it easy to select Rittal components (fans, air/air exch, air/water exch, air conditioners) for cooling.

Just remember, you are not trying to make the enclosure comfortable for you to be inside, just the electrical components. You have to find the component with the lowest temperature range and size for that so it doesn't fail.

Dont forget to take into account the cost of the compressed air in your calculation of total cost of the system.

Much dislike for Vortex coolers. They are extremely expensive to operate, noisy, and can promote in-cabinet condensation, even icing up. Humid environments exacerbate the problem.

My overall preference is for isolated (inside to outside) air to water heat exchangers.

Can you give a link or example. i have never seen air to water exchanger setups for control panels. Sound like the best method though.

really? icing up? seriously??? lol i always thought that these vortex things were limited to a cooling effect of 20-30F below the temp of the compressed air - so the only way i could see icing is if your plants temp is only 50-60F but if its that cool you wouldn't need to worry about Enclosure cooling anyhow wouldn't you?

The Plc Kid said:

Can you give a link or example. i have never seen air to water exchanger setups for control panels. Sound like the best method though.

Click to expand...

Think of heater in your car, panels with hinged doors
OK jokes aside, an automotive outfit that makes car radiators could easily make something that would provide you with a water to air heat exchange.

I'm glad someone mentioned "Air/Water heat exchangers", the option should at least be considered. I've had a few issues with them though. The coils don't last forever, and when they fail, well, you can guess where the water can end up. They can ALSO scale up on the inside from the minerals in the water.... leaving them with reduced capacity to transfer heat.

How many panels are you talking about? How spread out are they?

It wouldn't be insane to consider a "central" a/c unit. You could use a "split system" so the heat generated and the a-m-b-i-e-n-t temperature under consideration would be outside somewhere or even on the roof.

Then a small flex duct to, and a small flex return from, each panel would be needed to remove the heat, as mentioned before, just enough to keep the equipment happy. You're not trying to keep your BEER cool here.

Worst case situation..... you may need thermostatically controlled vanes in those panels that are difficult to regulate.

It's MY guess that a system like that would COST LESS than a bunch of individual little panel A/C units, cost less to operate, and cost less to maintain.

Just thinking out loud......

Stationmaster

I've used these guys a lot.

http://www.norenproducts.com/Compact_Cabinet/

We built a skid mounted welding machine for the oil field that was shipped down to Brazil. Since it had a chiller built in we used one of the Noren water/air heat exchangers to cool the cabinet. When I got there to oversee the startup, I opened up the enclosure and found several cans of soda sitting in front of the cooler. The local operators had discovered that it was the coolest place around. The Noren cooler kept it at about 60F (15C) even though the enclosure was out in the sun. (It would have been better to drop the sodas into the chiller tank, but they hadn't thought of that yet.)


The Noren heat pipe type coolers work really well for most indoor environments with moderate heat loads and where cooling below am-bee-int is not required.

Not sure of the Brand name, but I have seen the water/coolant filled heatexchangers on cabinets. They were on injection mold machines. Over the years found the main issue to be scaling. We built a small pump with a resvour that we put CLR in to clean the coils. We would flush them around once a year. The colant was from an evaporative chiller so it stayed around 80 degees F in the summer. This did not get the cabinets "cold" but was able to absorbe the heat generated by the controls. And cabinet temp stayed around 85 degrees F.

The setup consisted of a heat exchanger coil and 2 6 inch fans. Everything was inside the cabinet so you did not have to worry about contamination.

Infact they worked so well I took a couple of used ones and installed them in my servo cabinet for my robot. A failed AC unit had cost me a couple of drives.

Originally posted by Controls Engineer79:

...always thought that these vortex things were limited to a cooling effect of 20-30F below the temp of the compressed air...

Click to expand...

Allowing air compressed to 100PSI to decompress is enough to lower it's temperature by 20-30 degrees. You would basically be using the air as a refrigerant. Vortex coolers do more than this in terms of heat transfer. It is why the air exiting the coolers is quite hot. While have never seen it happen myself (due to throttling) I easily believe you can cause freezing in these things.

Keith

Yes, we also had freezing to the point that I had to take ice out in chunks. First person from the factory told me no adjustment on unit. When the Sales person called me and I told her they weren't working, she had someone call and say there is a built in thermostat. So now it is much better, but I think an external adjustment woud be best.

George

The Plc Kid said:

Who makes the best air power coolers? I have been looking at exair brand http://www.exair.com/en-us/Pages/default.aspx as well as vortec http://www.vortec.com/vortex_ac.php

I just wanted to get some opinions from people that use these.

Are they typicaly better than an ac unit for a enclosure?

Our ac units do not perform that well because the plant is so hot also.

Click to expand...

Kid
Any chiller can create condensation of atmospheric water on its exterior surfaces. ASSUME you will get water on surface install and put in a drain to make the water go where YOU want it to go.

METHOD -------- INSTALL -------- OPERATING -------- MAINT
-----------------COST ---------- COST ------------- COST
Fan w filter -----low -----------low ------------- medium

vortec -----------low ---------- high ------------- low

chilled --------- low/med --------low ------------- med
water (assuming you have chiller unit already)

Integral ---------- high --------- low/med -------- medium
A/C

Vortec is a hog of a plants most expensive utility - compressed air however if you are space limited may be only option. Watch out for condensation and for water in the air - run exhaust air outside the cabinet

Fan and filter service life depends on how much dust and other contaminants get in fan. Filters must be small enough to filter out nuisances. Most effective when this puts a positive pressure on cabinet thus leaks go from inside to out and reduce dust loading inside cabinet. CHANGE FILTERS pain in xxx and management squaks over cost. Will not be very effective if area temperatures are high ie over maybe 85 to 90?

Chilled water may be prettty inexpensive to install if lines are already in immediate area. Antifreeze will help to reduce corrosion so will additives - jacks costs - another maintenance item.
WATCH OUT FOR CONDENSATION IF SYSTEM TEMP
< 45 or 50 espeicially in high relative humidity climate.

Integral air conditioning ie heat pump air to air. works very well - high install cost - life cycle about 10 years or so on compressor, power draw between 250 watt to 1Kw depending on size. Will not work well if area temps very high ie 95 plus (condensor efficiency inverse proportional to area temp)
WATCH OUT FOR CONDENSATION ON EVAPORATOR (the "cold portion" inside cabinet) you WILL get condensation.

Dan Bentler