Design Builder's Energy Plus Simulation Took 3.5 Hours

Hi Everyone,

Somewhat of a novice to this building energy modelling.. I am using design builder and enegry plus. My building is 19,000 m2 floor area, I am running a cumulative analysis for this building to demonstrate specific improvements and their reductions in energy and electrical usage.

I have ran a baseline simulation, recorded the results, then I modelled improved windows, recorded results, then I modelled improved u values for flat roofs. All capturing the previous improvements and showing a pathway to reduce X amount. But when I model 600 m2 of solar panel array split across 2 arrays, the simulation last night took 3.5 hours to run. I've optimized my RAM to run through DB, good internet.

Is this normal for this to run this long? Usually other simulations take 40 minutes (new windows/roofs). Any help is much appreciated.

Ronan

asked 2024-07-25 03:42:09 -0500

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There could be several reasons for longer simulation time, but a common one is selecting too many outputs at short timesteps over a long simulation period. You can find guidance on speeding up up here https://designbuilder.co.uk/helpv7.3/... or contact our support team for help.

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Dave

answered 2024-07-27 00:39:18 -0500

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You can also explore the use of multipliers. It often cuts down time without compromising any results.

Regarding the runtime of about 3.5 hours, DesignBuilder often divides the runtime into actual runtime and postprocessing of the results. If you could see the actual energyplus runtime less than the results processing, this would also help you troubleshoot your model and optimize runtime parameters by removing some unused output parameters.

kartikay.sharma

answered 2024-07-29 08:07:55 -0500