Re: [EnergyPlus_Support] Convergence issue-- does this matter?

Space Discretization Constant 1

Relaxation Factor 1

Inside Face Surface Temperature Convergence Criteria 0.01

The relaxation factor at its lowest as I had it maximized the number of nodes to be considered, the max setting that Saleh suggested minimizes nodes, unless E+ "decides" that more nodes are in order to achieve heat balance

convergence

Jeremiah D. Crossett

CleanTech Analytics

503-688-8951

www.cleantechanalytics.com

This document may contain valuable information proprietary to CleanTech Analytics which is private and confidential. It may not be shared, copied, stored or transmitted in any form without the prior written consent of CleanTech Analytics

On Fri, Mar 23, 2012 at 8:15 AM, Vinay Devanathan <vinay.devanathan@xxxxxxxxx> wrote:

Saleh,

Please tell me what do you refer to as the relaxation factor?

THank you.

On Wed, Mar 21, 2012 at 3:30 PM, saleh saadi <salehsnjsaadi404@xxxxxxxxx> wrote:

No problem.
regards

From: CleanTech Analytics <jeremiah@xxxxxxxxxxxxxxxxxxxxxx>
To: EnergyPlus_Support@xxxxxxxxxxxxxxx

Sent: Tuesday, March 20, 2012 10:14 PM
Subject: Re: [EnergyPlus_Support] Convergence issue-- does this matter?

Saleh, Again thank you for your help!
Thought I had tried that, but must not have..

Thanks again!

Jeremiah D. Crossett
CleanTech Analytics
503-688-8951

www.cleantechanalytics.com

This document may contain valuable information proprietary to CleanTech Analytics which is private and confidential. It may not be shared, copied, stored or transmitted in any form without the prior written consent of CleanTech Analytics

On Tue, Mar 20, 2012 at 9:07 PM, saleh saadi <salehsnjsaadi404@xxxxxxxxx> wrote:

Jeremiah,
I ran your file on my machine on Denver weather file after changing the relaxation factor to 1 and increasing the # of max warm up period to 100 and set the min warm up period to 6.

E+ version 7 (32 bits) your is 64bits.

Here is what I got:
Program Version,EnergyPlus-32 7.0.0.036, 3/20/2012 9:43 PM,IDD_Version 7.0.0.036

   ************* Beginning Zone Sizing Calculations

   ************* Testing Individual Branch Integrity
   ************* All Branches passed integrity testing
   ************* Testing Individual Supply Air Path Integrity
   ************* All Supply Air Paths passed integrity testing
   ************* Testing Individual Return Air Path Integrity
   ************* All Return Air Paths passed integrity testing
   ************* No node connection errors were found.
   ************* Beginning Simulation
   ************* Simulation Error Summary *************

   ************* EnergyPlus Warmup Error Summary. During Warmup: 0 Warning; 0 Severe Errors.
   ************* EnergyPlus Sizing Error Summary. During Sizing: 0 Warning; 0 Severe Errors.
   ************* EnergyPlus Completed Successfully-- 0 Warning; 0 Severe Errors; Elapsed Time=00hr 11min 7.11sec

So, it might be the relaxation factor that gave those warnings. Try 0.5 or 1.
regards,
saleh

From: CleanTech Analytics <jeremiah@xxxxxxxxxxxxxxxxxxxxxx>
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Sent: Tuesday, March 20, 2012 7:36 PM
Subject: [EnergyPlus_Support] Convergence issue-- does this matter?

Dear List,
I have been working on this file for many a days, attempting to have a warning free run.

The simulation is for a Phase Change Material, and is producing good results so far as energy savings, heat flux reduction, HVAC size reduction, and Peak load reduction. The file is to be used in a climate study of various melt temperatures, so determine best product for each ASHRAE climate.

There are no errors without the PCM, and I have all three convergence settings, and relaxation at max values (the file did not work with lower)

I realize I could ignore this, but would like to figure out the issue and fix it if at all possible... Thanks

Program Version,EnergyPlus-64 7.0.0.036, 3/20/2012 4:37 PM,IDD_Version 7.0.0.036
************* Beginning Zone Sizing Calculations

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.344E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=COOL, at Simulation time=08/21 05:16 - 05:18

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.288E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=COOL, at Simulation time=08/21 07:28 - 07:30

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.199E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=COOL, at Simulation time=08/21 09:56 - 09:58

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.106E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=COOL, at Simulation time=08/21 12:08 - 12:10

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.005E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=COOL, at Simulation time=08/21 15:16 - 15:18

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.170E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=COOL, at Simulation time=08/21 18:44 - 18:46

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.018E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=HEAT, at Simulation time=02/21 09:46 - 09:48

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.401E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=HEAT, at Simulation time=02/21 15:46 - 15:48

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.421E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** During Sizing, Environment=HEAT, at Simulation time=02/21 17:32 - 17:34

************* Testing Individual Branch Integrity
************* All Branches passed integrity testing
************* Testing Individual Supply Air Path Integrity
************* All Supply Air Paths passed integrity testing

************* Testing Individual Return Air Path Integrity
************* All Return Air Paths passed integrity testing
************* No node connection errors were found.
************* Beginning Simulation

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.347E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** Environment=COOL, at Simulation time=08/21 05:16 - 05:18

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.288E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** Environment=COOL, at Simulation time=08/21 07:28 - 07:30

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.199E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** Environment=COOL, at Simulation time=08/21 09:56 - 09:58

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.105E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** Environment=COOL, at Simulation time=08/21 12:08 - 12:10

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.005E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** Environment=COOL, at Simulation time=08/21 15:16 - 15:18

** Warning ** Inside surface heat balance did not converge with Max Temp Difference [C] =1.170E-002 vs Max Allowed Temp Diff [C] =1.000000E-002
** ~~~ ** Environment=COOL, at Simulation time=08/21 18:44 - 18:46

************* Simulation Error Summary *************
*************
************* ===== Recurring Error Summary =====
************* The following recurring error messages occurred.

*************
************* ** Warning ** Inside surface heat balance convergence problem continues
************* ** ~~~ ** This error occurred 459 total times;
************* ** ~~~ ** during Warmup 0 times;

************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=5.370517E-002 [C] Min=9.900995E-003 [C]
*************
************* EnergyPlus Warmup Error Summary. During Warmup: 0 Warning; 0 Severe Errors.

************* EnergyPlus Sizing Error Summary. During Sizing: 9 Warning; 0 Severe Errors.
************* EnergyPlus Completed Successfully-- 474 Warning; 0 Severe Errors; Elapsed Time=00hr 26min 21.93sec

Jeremiah D. Crossett

CleanTech Analytics
503-688-8951

www.cleantechanalytics.com

This document may contain valuable information proprietary to CleanTech Analytics which is private and confidential. It may not be shared, copied, stored or transmitted in any form without the prior written consent of CleanTech Analytics

--
Vinay Dev