Cubicle Cooling

Do you have electrical panels in cubicles? The title to this thread is "Cubicle Cooling", but I don't see any mention of office partitions in the question itself.

Dear Mr.Moose,

Industrial cubicle system is actually metal cubicle comprising a triangle profile structure,welded closed at the top and bottom frame,with removable screw in vertical profiles to give the unit strength and versatility.

Application: Industrial cubiclefor PC,MCC Panels,MDB's.

Outstanding! Thanks for the additional details, prasobh83. This is not a question I'm able to answer, but hopefully the extra information will enable other CR4ers to help you.

Regards,

Moose

Hi,

Panels for industries have an ambient temp at which they should work. This is pre-defined during design stage. Their are lovers provided for ventilation to cool the panel. Some times small fans are installed to extract the heat.

If the temperature of panel is high, it may affect the equipments/instruments inside it. You can place a portable fan near the panel to provide cooling. But if you require extra cooling - you need to provide it through a duct connected to an AHU so that some chilled air (moisture free) can come in contact with the panel and provide cooling.

regards,

Ashish

In each part of equipment your installing inside, do you have its Temperature rise above Ambient caculations/results?

As its ambient temperature will be the insides of the enclosure, then the Thermal resistance from inside to outside will be the thermal conductivity (DegC(F)/W)

If your running a "non-ventilated" enclosure, you'll have to design a system which will remove the generated heat inside the box, and transfer it to the outside environment.

This has been done previously using Heat-pipe technology through the sides of the enclosure with the heat fins on the outside and fan force inside for circulation

What you need to establish the Ambient temp where this panel is sited.

Find out what is the heat load coming form within the panel.

Know the size LxBxH of the panel

What material it is made of steel sheet, aluminium, stainless/steel...

Is this panel sited in the outdoor or indoor

Follow this link http://www.pfannenbergusa.com/software/download-sizing-software.html & download the free software that will precisely tell you what is the cooling capacity

Good luck,

Philip Koh

Snaiktails has answered your question very well.

To add to it, you are in a better position to assess the heat load that is to be dissipated. Every cubicle has different kinds of switchgears going inside from push buttons, drives, contactors, relays and even transformers. Each of these will dissipate certain amount of heat which is given in to the cabinet. The walls of cabinet dissipate some amount of heat to ambient and if it is not sufficient, you involve a fan (with filters) to draw fresh air from ambient to remove the heat. For higher heat removal and depending on other criteria like quality of fresh air, you may have to choose from Heat pipe heat exchangers or even vortex coolers (requires compressed air). all said and written, except in vortex coolers, ambient plays a major role and the T achievable depends on the thermal resistance that you are ultimately able to achieve as is already mentioned by Snaiktails. visit www.capri.co.in

I'm working on a project which require IP65 Enclosures, thats where you can't use fans for removing the heat, but heat load is the most important data you need in order to size the enclosure cooler, some drives like soft starter and inverter generate a lot of heat , you can check from RITTAL website for enclosure Refregerant Air Conditioner, they do have many models for you to choose.

http://www.rittal.com/products/katalog.asp?FirstNav=1&ViewAt=3&lang=GB&Dom=com

but let me warn you, it is not going to be cheap. be prepared for it.

William Tan

Thank you for your help.I am using HIMEL Enclosures.They also have cooling units for panels.But for MCC's and all if we go for cooling units it will not be a cost effective solution.An IP of 55 range will do for me.

Pfannenberg (www.pfannenbergusa.com) offers a variety of solutions for cooling electrical cabinets. Depending on ambient temperature and dust in the enviroment there are different closed and open loop solutions.

Oh, I see, you only want the calculation right? Try this one :

To Calculate the TOTAL HEAT LOAD for your panel

Total Heat Load = Heat Dissipated within the enclosure + Heat Transfered from outside into the enclosure

1. Determine the approx. watt of heat generated within the enclosure

watts x 3.41 = (internal heat load ) Btu/hr

2. calculate outside heat transfer:

a. Determine the area in ft sq exposed to the air, ignoring the top of the enclosure

b. Determine the temp diff between maximum surrounding temp and desired internal temp. Then, use the temp conversion table below to determine the Btu/hr/ft sq for that differential, multiply the cabinet surface area times Btu/hr/ft sq, that will provide you the value for external heat transfer in Btu/hr

3. Add the internal and external heat load for TOTAL HEAT LOAD

Temperature Conversion Table

(Temp. Diff ) Btu/hr/ft sq

(5 ) 1.5

(10) 3.3

(15) 5.1

(20) 7.1

(25 ) 9.1

(30 ) 11.3

(35) 13.8

(40) 16.2

William Tan

william@spmultitech.com