(911) Power Plant HVAC Failure (911) 1

[Echoshill]

Hey Guys,

I am trying to verify some results from a CFD program and the last thing I have is time because it is the end of the fiscal year.

I need to be reminded of the formula for temperature rise in a room. I have a 819CuFt room at 85F. When the power fails, only the secondary HVAC runs which is 300CFM @55F at the vent. The only equipment in the room is two UPS systems generating a total of 7103W (24258BTU/Hr).

How many degrees per hour will the temp rise?

 

[MechEngNCPE]

In a perfectly insulated room your temp will settle at around 130F, you should be fine. But seriously, you need to know heat rejection from the envelope -U values, etc. You will not have much time to get power back up and running, I would guess around 4 hours before you get 100+. Good thing is UPS's are usually good up to around 110F.