Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
In my experience DesignBuilder's runtime is very close to EP Launch.
-Have you tried exporting the IDF from DesignBuilder and then running it in EP Launch to test out whether this is a DB or an EP issue?
-Have you ensured that you're running the simulation at the same timestep and shading calculation period?
-Are you using the simulation manager or just running directly within DesignBuilder? The simulation manager might not be faster but it allows for 3 simulations at a time and runs in the background so it reduces the headache of long simulation times.
One other quick thought from experience, without knowing the details of your model - the addition of perimeter radiation can drag down simulation time quite a bit in comparison with other hvac controls that would seem comparably complex to model. If you do have perimeter radiation, try switching up the type (i.e. radiator to convector or vice versa) and seeing if it impacts the simulation time.
