I am running DOE prototype measure in PAT and OS and I am getting different results each time

asked 2021-06-30 13:52:56 -0600

Rwadhwa910's avatar

updated 2021-07-01 12:17:04 -0600

Main difference in consumption lies in Cooling and Ligthing how is that possible since all the variable location, Template climate zone are same.Although the difference is not that big but still it should be same.image description

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Are you running a parametric analysis and changing any of the parameters (materials, HVAC, geometry) each run? If you are changing something like lighting power density (LPD) in W/m^2, that might cause the discrepancies in your model. If you are just running the same exact model in OS/PAT 2x, you are correct, there should be no difference in the results summary.

sashadf1's avatar sashadf1  ( 2021-06-30 16:32:28 -0600 )edit

Everything is the same So this is my baseline model with no measures.

Rwadhwa910's avatar Rwadhwa910  ( 2021-06-30 16:40:31 -0600 )edit

Grab the IDFs from the two runs that give different results and diff them in a tool like WinMerge. Are they the same or different?

shorowit's avatar shorowit  ( 2021-07-01 10:17:54 -0600 )edit

@showrowit I could see some difference in construction and other things but why is this happening moreover when I ran the same measure in OS 1.0.0 my EUI has reduced to 53.85 KBTU/sqft/yr as compared to 55.23 in PAT and 54.79 in OS 1.1.0. I am confused as to location and everything else is same.


Rwadhwa910's avatar Rwadhwa910  ( 2021-07-01 10:55:52 -0600 )edit

OS 1.1.0 uses EnergyPlus v9.4 while OS 1.0.0 uses EnergyPlus v9.3. There are lots of bugfixes and model improvements between EnergyPlus releases, so it's not unusual for results to change by a small amount. For example, there were dozens and dozens of changes in EnergyPlus v9.4.

shorowit's avatar shorowit  ( 2021-07-01 12:32:37 -0600 )edit