Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Hi @Xandrika, have you tried increasing the "Maximum Number of Warmup Days" in the Building object to see if it converges?
| | 2 | No.2 Revision |
Hi @Xandrika, have you tried increasing the "Maximum Number of Warmup Days" in the Building object to see if it converges?
== Update ==
After experimenting with the IDF model @Xandrika has uploaded on the development server, it seems that the convergence problem was caused by the internal thermal mass construction. The original model uses the same construction of internal partition wall (NP_Partition) for addition thermal mass. The simulation result showing convergence failure can be seen here: http://server2.ensims.com:2995/ServletJESSadmin/jobview.html?ID=14439
If the thermal construction is slightly modified for the west zone, i.e. using 2cm cement sand render as the outer layer instead of 1.3cm cement plaster sand aggregate (see NP_ThermalMass), the convergence problem disappears. This result can be seen here: http://server2.ensims.com:2995/ServletJESSadmin/jobview.html?ID=14449. Note that the east zone still has the same internal mass construction, therefore it is not the 1.3cm render layer itself causing troubles.
I thought the E+'s solver might not like symmetrical (identical) thermal mass in the east and west zones; but this is not the case. The model converges fine if both zones has 2cm cement sand render as the outside layer: http://server2.ensims.com:2995/ServletJESSadmin/jobview.html?ID=14451. So the cause of the convergence issues remains a mystery...
