Gererac Exhaust Pipe Sizing

[BronYrAur]

Anyone familiar with a Generac Model QT080 generator? It is an 80 kW unit with a 5.4L natural gas engine. It is designed to be installed outdoors, but I have been asked to put one inside. Since we are going against the manufacturer's intent, they are not offering any help ... other than helping us to know that the warranty is void.

All I know on the exhaust is that it is 649 CFM @ 800 Deg F. I do not have any information on backpressure, etc. The generator will sit in a basement and the flue must be routed up 7 stories to the roof.

How do I size the flue pipe with no help from Generac?

 

[DrRTU]

What about the UL rating? The local AHJ will require the plant is installed as per mfgs instructions. What happens when the unit catches on fire? I believe you will take on tons of liability. Can Generac take the unit back and modify the plant? An 80 KW is not a big unit, sell it used and buy the correct plant.

 

[Wareagl487]

DrRTU stated it best - it is a HUGE liability. If the manufacturer won't stand behind an interior installation - that's all I would need to know. I wouldn't stamp a design as such.

My question with venting any generator is it capable of +70 feet of vertical discharge for the exhaust.

Andy W.