Diesel Generator Set Room Air Recirculation 1

[m2e]

For utility buildings, diesel gen-sets are used as a backup or even primary power source. The gen-set is in a separate room, but in the same building as the main utility room (electrical panels, pump, MCC, etc). The gen-set is not for fire safety, or life safety systems, just to provide power for the building's equipment. Can the air be circulated between the two rooms, when the gen-set is and is not running?

 

[Drazen]

why would you want to circulate that air?

 

[willard3]

You want to use warm air for combustion? Not such a good or efficient idea.

 

[m2e]

When it's -30C outside, the building lost power, the genset kicks in, and instead of dumping warm air outside and run the heater on the other room, circulating some warm air into the other room can save some fuel. But my primary question is if the code says anything about it.

 

[ProcessHVAC]

I have done it, building code here allows it and it helps with building heating. Clarification: it's hot air from the engine cooling system and not exhaust air which is toxic.

 

[Drazen]

As process said, punctually and star deserving.

just add air filters to recirculation setup. you don't want lifted dust to wander around

 

[m2e]

Thanks for the reply. Appreciated. How about when the gen set isn't running, which would be most of the time? With a subbase fuel tank there's some diesel fume in the room probably. Not flammable, but combustible? Do you have to seal the room or the duct can remain open?

 

[317069]

what about using HRV's

 

[MintJulep]

What about when it is not -30C? Will the generator waste heat cause your switchgear room to overheat? Or will you install some sort of dampers and controls?

Even well maintained diesel gensets have the annoying habit of bursting into flame occasionally. The resultant sooty smoke and fire extinguishing agents are not all that good for electronics.

You really need to look at the life-cycle cost.

My get tells me that for an emergency generator room it will be a loser.

If the generators are used continuously for primary or supplemental power then it may make sense to recover jacket cooling and exhaust waste heat and put it to use.