[Equest-users] UA Convergence Error

[Paul Diglio]

Hi David:
No heat exchangers in the .inp file.
Thank you,
Paul Diglio
87 Fairmont Avenue 
New Haven, CT 06513 

203-415-0082 

    On Tuesday, December 10, 2019, 10:46:12 AM EST, David Eldridge <deldridge at grummanbutkus.com> wrote:  
 
 I didn’t think of this earlier, but search the *.inp to see if one is in there associated with the AHU that crashes, maybe some relic code is in the file that isn’t shown in the UI.

DSE Mobile773.490.5038

On Dec 10, 2019, at 9:30 AM, Paul Diglio via Equest-users <equest-users at lists.onebuilding.org> wrote:



Hi Sharad:
I can't find any heat exchangers in my model.  How did you pull up the heat exchanger screen?
Thank you,

Paul Diglio
87 Fairmont Avenue 
New Haven, CT 06513 


On Tuesday, December 10, 2019, 9:29:01 AM EST, Sharad Kumar via Equest-users <equest-users at lists.onebuilding.org> wrote:

Hi Paul,
I think the problem is being caused due to some heat exchanger kind of thing being modeled in the built.

I am guessing out the problem as follows:
The UA calculations does not converge as there can be might possibility that then UA product and after multiplication with delta T does not converge with the meeting of the capacity as the formula is Q= U* A* delta T.
Q=  CapacityUA= product of conductance and cross sectional area.delta T= Temperature difference between ends.
<image.png>
  Hence try to succumb with the problem in lieu-wise as above.

<image.png>

The other factors to have the UA product calculations to be right are as in above help page super-script which might can also guide as there are other factors based calculations is there as if there the boxed figure are outrun.
Hope this might help.
Thanks and regards,Sharad.KumarFreelancer-Energy Simulation and Day-lighting.
.....................................................................................................................................................
---------- Forwarded message ----------
From: Paul Diglio <paul.diglio at sbcglobal.net>
To: Equest-users <equest-users at lists.onebuilding.org>
Cc: 
Bcc: 
Date: Mon, 9 Dec 2019 11:13:13 +0000 (UTC)
Subject: [Equest-users] UA Convergence Error
Hi Folks:
I am getting a "heat exchanger XX Sys1 UA calculation failed to converge" error.  The model has three building in it and only two air handlers per building.  I don't have any heat exchangers attached to the air handlers or any heat recovery installed.

Sometimes the error occurs when I change the glass type via the library and other times I get the error when I adjust the air changes per hour in one or two zones.
In the example above, the error was for system B2, but it varies...sometimes systems A or C 1 or 2.
Any ideas what the problem could be?  

Thank you,

Paul Diglio
87 Fairmont Avenue 
New Haven, CT 06513 


_______________________________________________
Equest-users mailing list
Equest-users at lists.onebuilding.org
http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
_______________________________________________
Equest-users mailing list
http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
<image.png><image.png>_______________________________________________
Equest-users mailing list
http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG

  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20191210/d344fcd4/attachment.htm>