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How to select appropriate DesignDay objects for Winter and Summer from ddy or ddm files

asked 2015-09-17 20:54:27 -0500

PJRosado's avatar

updated 2015-09-29 07:37:49 -0500


I want to update the .idf files with the appropriate SizingPeriod:DesignDay for SummerDesignDay and WinterDesignDay.

The weather files I'm using are the CZ2010 versions, which I obtained from White Box Technologies. When downloaded, they included .ddy and .ddm files. But how can I adequately determine which DesignDay objects to choose from within these files (they include Clg 0.4%, 1%, 2%, and variations of DB, WB, etc)?

Also, the .ddm files include options for SummerDesignDay for each month of the year. Is it wise to have 12 SizingPeriod for SummerDesignDay to represent the 12 months?

Also, is there an easier way (other than use some python code) to automatically update the .idf files with these DesignDay objects?

Thank you in advance for your help!


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answered 2015-09-29 07:26:31 -0500

A simple way to update your Design Days would be to

  • create an OpenStudio file with the data from appropriate ddy-file loaded.
  • Then export the osm-file e.g. to file aux.idf
  • Then copy manually the design days in IDF Editor from aux.idf to your idf file.
  • Run test simulation and check whether target temperatures etc. remain within desired bounds.
  • If OK, you will probably not need 12 sizing periods.
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Asked: 2015-09-17 20:54:27 -0500

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Last updated: Sep 29 '15