[Equest-users] SUPPLY-KW/FLOW

[Vikram Sami]

Maybe I'm mistaken here, but I've always understood the Supply flow to
be kW/cfm. So if your design condition is 9.9 BHP, what is the design
flow rate (in cfm) that goes with that?

 

So for instance if your design flow rate is 20,000 cfm at 9.90 BHP, then
your Supply KW/Flow = 12.83/20,000 = 0.000642

 

 

 

 

Vikram Sami, LEED AP 
Direct Phone 404-253-1466 | Direct Fax 404-253-1366 

LORD, AECK & SARGENT ARCHITECTURE



 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Lars
Fetzek
Sent: Wednesday, September 16, 2009 4:48 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] SUPPLY-KW/FLOW

 

eQuesters & DOE2-2ers,

 

    The DOE2-2 dictionary loves to use the phrase, "total fan power per
unit flow" in defining SUPPLY-KW/FLOW.  Clear as mud.

    I figured this:  At design conditions, the supply fan runs at 9.90
BHP and 61.89% efficiency and the per-unit flow is at unity ( x CFM / x
CFM = 1).  The motor nominal efficiency is 93%.  (No, I don't have a
motor efficiency curve.)  0.746 kW  = 1 HP.  Therefore, the fan kW  =
9.90 * 0.746 / ( 0.6189 * 0.93 )  =  12.83 kW.  The per unit flow is 1.
So... SUPPLY-KW/FLOW  = 12.83, which I type into my .inp file.

    Naturally, eQuest gives me an error message, insisting that
SUPPLY-KW/FLOW must be between 0.0 and .0080.  Evidently, there is some
discrepancy involving units or the meaning of "per unit" in the context
of the quoted phrase.

    Can anyone clarify what eQuest really means and how to calculate
SUPPLY-KW/FLOW?  Is it supposed to be KW-per-CFM?

    Thanks!

 

Lars Fetzek, EI

Phoenix Engineering Group

Tampa, Florida

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20090917/27e6555f/attachment-0001.htm>