Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question

Define summer/winter and day/night periods

asked 2015-01-11 17:49:59 -0600

pursuit's avatar

updated 2015-07-11 09:28:06 -0600

Hello everyone.

I would like to know how can I simulate my model for a specific period of time: for instance during the summer period and only for night hours.

I'm using Ideal Air Loads and a default schedule for Medium Office by the way.

Thank you,


edit retag flag offensive close merge delete

2 Answers

Sort by ยป oldest newest most voted

answered 2015-01-11 23:20:12 -0600

updated 2015-01-11 23:43:22 -0600

The RunPeriod specifies the begin and end days for the simulation. In OpenStudio this object is referenced in the Simulation Settings tab.

I'm not aware of a way to specify the hours of the day so you may need to create a workaround for that using the other RunPeriod objects or postprocessing the output.

edit flag offensive delete link more


Thank you for your answer. Regarding specifying the RunPeriod days I manage to do it; for hours of the day I still can't do it... If anyone knows it I would appreciate it!

pursuit's avatar pursuit  ( 2015-01-12 02:35:05 -0600 )edit

Are you looking to simulate several days but only the nighttime hours or just one night? As far as I can tell there's no built-in way to do any of the two. I would certainly do some post-processing to achieve this (with Python for example)... Otherwise if it's one night, creating a custom weather file with only those hours could work.

Julien Marrec's avatar Julien Marrec  ( 2015-01-12 04:39:18 -0600 )edit

I was looking for simulate it during several days, lets say summer period, but only the nighttime hours...

I'm evaluating the potential of natural ventilation for those periods, so if I simulate only with a global RunPeriod (for the entire year) the result will not be so good it could be, I guess.

Thank you!

pursuit's avatar pursuit  ( 2015-01-12 06:14:16 -0600 )edit

I'm also unaware of a way to do this. But to be realistic you'd need to model the daytime hours anyway, since otherwise the building mass would not heat up during the day. I'd suggest running your simulation for just the summer design week, or alternatively for the whole summer.

Jamie Bull's avatar Jamie Bull  ( 2015-01-12 13:32:06 -0600 )edit

answered 2015-01-12 08:14:30 -0600

I'm not certain you can do it with Ideal Air Loads, but with an actual HVAC system you can certainly make the systems available only for the night hours by creating an Availability Schedule, then run your simulation over the period of months you are interested.

edit flag offensive delete link more


Ideal Loads can be scheduled just like any other system.

MJWitte's avatar MJWitte  ( 2015-01-16 16:26:00 -0600 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Training Workshops

Question Tools

1 follower


Asked: 2015-01-11 17:49:59 -0600

Seen: 122 times

Last updated: Jan 12 '15