[Equest-users] OA ratio stuck at 1

[Dakota Kelley]

Patrick,


The return fan for each system has only been half defined, so eQUEST is punishing you by running at 100% OA.  All systems have either 0.9 or 1.0 degree specified for the return fan temperature rise with no corresponding kW/CFM.  If you have return fans, enter the corresponding kW/CFM.  If not, “restore default” on the return fan rise.  Either one should put the needle back on the record. 

 

On a related note, a temperature rise has been specified for the supply fans, too, but the corresponding power was left at the default.  This is not causing the OA problem since both power and rise have been provided, but it would be worthwhile to specify the supply power and let the rise default, or simply restore default on the supply rise, too. 

 

Thanks,

 

                                

                         DAKOTA KELLEY                                                              

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From: Patrick O'Donnell [mailto:pco at MichaelsEngineering.com] 
Sent: Friday, February 26, 2010 4:53 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] OA ratio stuck at 1

 

Hi all,

I have modeled a simple PSZ with one system per zone.  Problem is that my OA damper is “stuck” open (just like the real world hehe or closed sometimes!). i.e. no matter what I do I cannot bring in less than 100% OA at the system level.  My “Outside Air Ratio” is shown as 1 in the detailed report for each zone and I don’t know why and I cannot change it.

I have tried messing with OA ratio, restoring the defaults, eliminating the economizer all together, setting OA to zero at system and zone level but nothing seems to change the Outside Air Ratio of 1 or the hourly reports showing 100% OA.

With this scenario, one system per zone, my system and zone level are essentially the same.  I can adjust my zone-level OA down but for example the hourly reports show SA CFM at 1500 and Ratio of OA to SA is .9999 for a particular zone and that zone’s SA is 1500 CFM which has be all OA then, right?

Has anyone encountered this issue?? I have attached .pd2 and input file for viewing.  If anyone can tell me how I can turn off 100% OA I would be glad to know.   Any other assistance or ideas are appreciated.  Thanks, 

-Patrick

<<Base1.inp>> <<Base1.pd2>> 

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