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duygualb
Posts: 10
Registered: ‎05-09-2011
Message 1 of 5 (1,069 Views)
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Questions on changing Air Infiltration Value- Outdoor Air per Area (CFM/SF)

1069 Views, 4 Replies
10-17-2013 10:29 AM

Hi,

 

I have used Revit 2014 Architecture to model several houses and for my research, I need to perform energy analysis by changing air infiltration value as one of the parameters. I have been using Building Element Mode to run the energy analysis in GBS website. 

In Revit, when I change the default 0 of Outdoor Air per Area (CFM/SF) to any other value and run the energy analysis (Img 1), there is a noticable change in the EUI and other numbers in GBS. However, in gbs website, I tried to change the air infiltration value- Outdoor Air per Area (CFM/SF) - through creating a design alternative and it did not allow me to do so (Img 3 and 4). 

 

On the other hand, it has its own default numbers in a different format (ACH) under Alternative Runs.

 

Could you please help me how I can change the Air Infiltration Value (Outdoor Air per Area CFM/SF)?

 

 

 

GBS uses the "BlowerDoorValue" method of specifying infiltration in gbXML files. You can edit your xml file to use the schema elements supported by GBS and then directly upload the edited xml file to GBS. I've attached your xml file with the proper edits. Search for "BlowerDoorValue" to find it and edit the value for your ACH as needed.

 

Regards,

Employee
mstein7484
Posts: 97
Registered: ‎03-16-2009
Message 2 of 5 (1,048 Views)

Re: Questions on changing Air Infiltration Value- Outdoor Air per Area (CFM/SF)

10-21-2013 09:36 AM in reply to: duygualb

 

The outside air and infiltration are not interchangeble --they are completely different "parameters" acting upon the building and they are assumed to be in effect using different schedule assumptions and different amounts based upon zone/space locations (core zones have little infiltration compared to perimenter zones.)

 

You could edit the gbXML file generated by one of the infilltration parameter runs automatically generated by GBS for your project and upload the edited file directly to GBS.

 

Regards,



Marjorie Stein
QA Analyst
Green Building Studio
Autodesk, Inc.

bpa.team@autodesk.com
Active Member
duygualb
Posts: 10
Registered: ‎05-09-2011
Message 3 of 5 (1,010 Views)

Re: Questions on changing Air Infiltration Value- Outdoor Air per Area (CFM/SF)

11-08-2013 01:21 PM in reply to: mstein7484

Thank you so much for the feedback! I have another question regarding how to change the infiltration value in the gbXML file. 

 

I have opened gbXML file in notepad; couldn’t find any parameter on air infiltration if I export the project as a room based gbXML. However, if I export it as space based gbXML, there is a parameter called air infiltration. Unfortunately as I read through internet and tested by myself, that parameter is not carried to GBS. I have attached two files: Test2 (Space based GBXML) and Test3 (Room based GBXML). 

 

I would really appreciate if you would help me about this.

Employee
mstein7484
Posts: 97
Registered: ‎03-16-2009
Message 4 of 5 (955 Views)

Re: Questions on changing Air Infiltration Value- Outdoor Air per Area (CFM/SF)

11-27-2013 05:51 PM in reply to: duygualb

GBS uses the "BlowerDoorValue" method of specifying infiltration in gbXML files. You can edit your xml file to use the schema elements supported by GBS and then directly upload the edited xml file to GBS. I've attached your xml file with the proper edits. Search for "BlowerDoorValue" to find it and edit the value for your ACH as needed.

 

Regards,



Marjorie Stein
QA Analyst
Green Building Studio
Autodesk, Inc.

bpa.team@autodesk.com
Active Member
duygualb
Posts: 10
Registered: ‎05-09-2011
Message 5 of 5 (885 Views)

Re: Questions on changing Air Infiltration Value- Outdoor Air per Area (CFM/SF)

12-16-2013 10:04 PM in reply to: mstein7484

Thank you so much for your help!!!

 

Best,

 

Duygu

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