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Legacy Open Studio

asked 2014-10-19 10:55:38 -0500

Carlos Vazquez gravatar image

updated 2021-05-07 12:06:26 -0500

I just realized that this version of legacy open studio has a bug. I am using it together with Sketchup 2014 Pro. It is not calculating the total floor area modeling a multistory building. I am using the copy tool in Sketchup to stack equal spaces one over the other. It's similar of what was happening with the older Open Studio version 1.4 when exporting Gbxml data.

Does anybody has the same problem? Is available any fix for this?

Thank you

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Hey Carlos, what is the exact error that you are seeing here? Is it that space area is not included in the gbXML export? Space area was added to the gbXML export in OpenStudio 1.5.0 at the request of Trane TRACE users. The legacy OpenStudio plugin does not support gbXML export at all, what was the problem you were seeing in the legacy plugin?

macumber gravatar image macumber  ( 2014-10-19 13:14:06 -0500 )edit

The error I am seeing is with the Object info tool within Sketch-up. If I make a model with different one-story buildings it calculates the floor area of each building. However, if I stack the floors in a multi-story building the result of total floor area is 0.

Carlos Vazquez gravatar image Carlos Vazquez  ( 2014-10-19 18:43:44 -0500 )edit

I have been doing more testing. Looks like the area calculation problem happens when using the copy tool from SketchUp together with the Energyplus zone dashed lines activated at the same time. However, when using the copy tool from SketchUp with the Energyplus zone deactivated the area calculation of the end result (a multi-story building) is calculated correctly. By the way, I think I didn't mentioned that I have SketchUp 2014 Pro version.

Carlos Vazquez gravatar image Carlos Vazquez  ( 2014-10-19 21:18:10 -0500 )edit

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answered 2014-10-20 10:00:40 -0500

Carlos, if you are using the legacy OpenStudio plugin and are within a zone, and copy the zone geometry up on top of each other you would see odd behavior. Generally zone geometry should be an empty shell with no extra surfaces included. In what you describe you would end up with two or higher story shell as a single zone, with multiplier surfaces floating in the middle. SketchUp can't have two surfaces in the same position with the same grouping. As a result you are probably ending up worth the middle surface being defined as a roof, and not a floor, and that area is not counting towards the floor area. It is also possible that the floor at the bottom is defined as the wrong type of surface which would affect the area. If you want to make a multi-story building in the legacy plugin you want to be outside of the zone group when you copy it so you are copying no just the surfaces but the group container as well which will make additional thermal zones.

The same logic of copying and pasting within a space applies to the current version of OpenStudio. While multiple spaces can be put into a zone, each space should be an empty shell. In this case if you want to have interior surfaces you can model them as interior partition surfaces, which look much like shading surfaces, but which can become internal mass objects in EnergyPlus. This is in fact what happens to common surfaces between two spaces which end up being part of the same thermal zone.

This question does touch on one condition that some users have had in the new OpenStudio when combining multiple spaces into a thermal zone. The most typical use case is having multiple adjacent spaces on the same floor combined as a zone. In that case the floor area of the zone matches the sum of the spaces. The shared inter-space walls become internal mass objects. We have had some people stack spaces vertically that are on different stories and combine them to a zone. In this case shared surfaces between the spaces are also turned into internal mass objects, but in this case we have an issue that the floor area of the zone isn't the sum of the floor area of the spaces. One solution we have talked about to support this is overwriting the "area" field in EnergyPlus with an OpenStudio calculated area. We could look at the floor construction used to see if the intermediate floor surfaces were intended to be real, or were stacked to mimic an atrium. We would do this by looking for an "air wall" construction, and not adding area if the intermediate floor uses that construction. If someone had to do this today, we could write an EnergyPlus measure to overwrite the area. Of course the user could also just model a single thermal zone and set the zone multiplier within OpenStudio.

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Asked: 2014-10-19 10:55:38 -0500

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Last updated: Oct 20 '14