Output:Table:Annual {Maximum} not matching
In my EnergyPlus simulation, I am requesting and comparing the maximum demand results for multiple variables/meters from different report summaries. For example, I am looking at the Electricity demand for the entire facility (Electricity:Facility) at the Demand End Use Components Summary. On the other hand, I am requesting an Output:Table:Annual summary for the maximum Electricity:Facility and other variables at that same moment.
Results on the Annual Table report are substantially higher, and the timestamp does not match from the regular summary table (Demand End Use Components Summary). Why is this happening?
I fully agree with your observation, just faced it in a project !.
I can say that
DemandEndUseComponentsSummary, and in general higher level Output (e.g. ABUPS vs. LEED Summary), are right, conversely manyOutput:Table:AnnualandOutput:Table:Monthlydo not give exaclty right values (checked against timestep data trend). Definitely annoying. I Think something in post-process happens.For example:
Output:Table:AnnualandOutput:Table:Monthlycan give as 'time of peak' values that cannot match simulation timestep : e.g. 30-JUL-15:53 with 6 timestep (= 10 min.).Moreover some value occurs at 08:61 or other timing not rasonable at all !
Hopefully some developer could pass here and give his point of view.
"For example: Output:Table:Annual and Output:Table:Monthly can give as 'time of peak' values that cannot match simulation timestep : e.g. 30-JUL-15:53 with 6 timestep (= 10 min.).". You're forgetting that there is a "Detailed" timestep (for HVACSystem) that's lower than the (Zone) Timestep you enter in the Timestep IDF object.
@Julien Marrec, In my case, I am looking at the Electricity:Facility maximum. It is so odd that the maximum is 3 times larger and at completely different date.
@Julien Marrec , yes you are right about HVACSsytem vs. Zone timestep. Anyway:
Some time of peak has no sense (e.g 08:61)
Monthly table built on
Facility Total Produced Electric Poweroutput variable gives a maximum different value than that reported intoDemand End Use Components SummaryMany other little errors, for exemple in building area conditioned/unconditioned/total , miscellaneous process load (EAp2-17a tab in LEED Summary report), and more ....
The management of the time in E+ is tricky (at best), so I'm not that surprised that you are getting 08:61. That basically means it's 9:00 AM and change... It was likely in the zone timestep that ends up at 08:60 (=9AM, but E+ in addition to having an end-of-interval reporting convention also uses weird notations like 24:00, 08:60), but with a non zero HVAC System timestep, hence a "little bit more than 08:60.
@Ag, If you want to see these fixed, please do open a issue on https://github.com/NREL/EnergyPlus/is... with example files producing the defect and highlighting where you see the discrepancies (eg an annotated screenshot of the eplustbl.htm). That will allow developers to reproduce and track down the issue and therefore address (I'd be happy to take a look at it myself). Thanks!
@Julien Marrec just reported some of them: #8486 and #8487 issue about conditioned/unconditioned/total is a little bit more complicated, I need to better understand it to reproduce it and finally share it