[Equest-users] VFD Pumping

[John Aulbach]

Michael. can you send your .pd2 and .inp for us to check youtvinputd, please?


John R. Aulbach ,PE

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From:"Mike Schaefer" <mikedschaefer at hotmail.com>
Date:Thu, Jun 18, 2015 at 11:49 AM
Subject:[Equest-users] VFD Pumping

I’ve performing an energy model to compare VFD Chiller pumping and Constant Volume Chiller pumping for a multi-story office building using eQUEST v 3.65. Although I expect to save pump energy utilizing VFD pumping I’m not seeing a savings and I believe this is due to my “Pump Properties Inputs”.

 

For both the VFD and constant volume pump scenarios I’ve input the scheduled pump flow (1,300 gpm) and head (200 ft) and the other pump inputs are default values. The energy difference between the two pumping scenarios is negligible, however, if I set the pump gpm to a default, which inputs a 1.00 Flow Ratio, the energy savings is significant in the VFD pumping model. 

 

Am I over defining the pumps by inputting the scheduled pump gpm? Should the pump gpm always be set to default?

 

Thanks,



Michael
  		 	 		 

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