# Electrical  Room  Cooling



## globe trekker (Mar 24, 2010)

I have an 8'  x  10' electrical room with 1 - 800A main,  3 - 225A subpanels,  1 automatic transfer switch,

and 1 - 75KVA floor mounted,  dry type transformer in it.    All of these components DO have the required

working clearances around them.     This room has 2 hr. rated wall  & ceiling assemblies and a rated door

vs.  having a sprinkler head installed in it.

*QUESTION:* Should this room have a cool air supply register to it, ...maybe even a ' dedicated '

cool air supply to it, according to either the fire code,  electrical code, or mechanical code?    We are

on the 2006 I-codes and the 2008 NEC.     The DP does not have either a supply or a return duct indicated

to this room.

Thanks for your input!     

.


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## Coug Dad (Mar 24, 2010)

Re: Electrical  Room  Cooling

If the power is used for smoke control systems, check Section 909.11.  There are provisons there for dedicated ventilation directly to the outside.


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## raider1 (Mar 24, 2010)

Re: Electrical  Room  Cooling

There is nothing in the NEC that would require this room to have any HVAC supply and return system.

450.9 does require transformers to be adequately ventilated so that the temperature rises don't exceed the transformer rating but most likely this can be done by just locating the transformer in accordance with the installation instructions and would not require additional ventilation.

Chris


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## McClary's Electrical (Mar 24, 2010)

Re: Electrical  Room  Cooling



			
				globe trekker said:
			
		

> I have an 8'  x  10' electrical room with 1 - 800A main,  3 - 225A subpanels,  1 automatic transfer switch,
> 
> and 1 - 75KVA floor mounted,  dry type transformer in it.    All of these components DO have the required
> 
> ...


450.9 covers ventilation for the xfmr, but does not specifically demand conditioned air. As long as the xfmr stays within it's temp limits , it would be legal. 110.13 b "implies" air flow,,,,,but does not require it


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## McClary's Electrical (Mar 24, 2010)

Re: Electrical  Room  Cooling

sorry chris,,,I was typing the same time as you were


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## north star (Mar 25, 2010)

Re: Electrical  Room  Cooling

*See Section 401.2   &   401.3 in the 2006 IMC.*

*401.2 Ventilation required.*

*"Every occupied space shall be ventilated by natural means in accordance with Section 402 or*

*by mechanical means in accordance with Section 403."*

*401.3 When required.*

*"Ventilation shall be provided during the periods that the room or space is occupied."*

*It would probably be a good idea to keep the conductors,  breakers and the transformer cool,*

*but it is not required.*

*The real question is, "is this an occupiable room / space?"    Will someone be engaged in labor*

*in this space?    [ as defined in the 2006 IBC,  Ch. 2 Definitions.  ]    Irregular visits to this room / space*

*probably would not classify it as ' occupiable ', ...IMO!*


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## McClary's Electrical (Mar 25, 2010)

Re: Electrical  Room  Cooling



			
				north star said:
			
		

> *See Section 401.2   &   401.3 in the 2006 IMC.*
> 
> *401.2 Ventilation required.*
> 
> ...


Even if they were,,,,you could meet 401.3 b ,,,,by leaving the door open while you work


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## globe trekker (Mar 25, 2010)

Re: Electrical  Room  Cooling

Thanks to you all for your input!    

Next *QUESTION:* In regard to Coug Dad' response, when would a Smoke Control System typically be required?

I am referring to Section 909 in the `06 IBC.

.


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## Coug Dad (Mar 25, 2010)

Re: Electrical  Room  Cooling

High rise will have smoke proof enclosure, typically pressurized stairs.  Atria more than two stories will have smoke control.  Underground buildings per 405.  Smoke protected assembly seating.


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