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Wrong volume calculation in OpenStudio

asked 2015-08-28 07:11:34 -0600

Aram's avatar

updated 2015-11-07 13:33:22 -0600

I´m working with OpenStudio 1.7.0 and I´ve found that the volumes calculated for 3 different thermal zones (from a total of 53 zones) in my model are not right. In 2 cases they are much bigger than expected and the other is slightly smaller... I already checked the geometry in SketchUp an everything looks fine, the OpenStudio files gives me no errors, but when I get the final report of the simulation the volumes shown are wrong. Is there a way to override the calculated value and enter the right one? I tried to change it saving my OpenStudio file as IDF and turning back to OS, but it didn´t work... any ideas? Thanks!

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@Aram: Did you look at This thread?

Waseem's avatar Waseem  ( 2015-08-28 08:33:51 -0600 )edit
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Is EnergyPlus calculating the correct volumes for these zones? How are you using OpenStudio to calculate the volumes? How do you know the correct volumes, did you calculate them yourself?

macumber's avatar macumber  ( 2015-08-28 09:45:40 -0600 )edit

@Waseem: Yes, I already looked at it, but it seems my problem is different. It is only happening in 3 zones and in the Sketchup model everything seems right...thanks anyway!

Aram's avatar Aram  ( 2015-08-31 03:48:57 -0600 )edit

I double-checked and the volume is wrong just in 2 zones. I saw the problem when looking at the EnergyPlus Results in OS. In the Zone Summary, the floor areas correspond with those of the floor plan of the building, and the volumes are ok (I just made a fast calculation: volume/area= height) because they correspond to the 3.15m height I draw in SketchUp. The exception are these areas for which the volume is much bigger, as if the height was 18m in one zone and 29 in the other...

Aram's avatar Aram  ( 2015-08-31 04:10:44 -0600 )edit

I am still unclear if the error you are seeing is in EnergyPlus's zone volume calculation or in OpenStudio's. I assume it is EnergyPlus's calculation. I would suggest you check for any surfaces that are pointing the wrong way and also make sure that your zone geometry is water tight (e.g. no holes or missing surfaces).

macumber's avatar macumber  ( 2015-09-01 21:57:14 -0600 )edit

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answered 2017-03-09 10:11:50 -0600

dani71's avatar

The same issue is discussed and resolved here by Jaime Bull:

https://unmethours.com/question/10628...

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Asked: 2015-08-28 07:11:34 -0600

Seen: 707 times

Last updated: Mar 09 '17