RE: [EnergyPlus_Support] LBNL Window IDF Problem

["Jean Marais jeannieboef@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx>]

Okay, we're on the same page. The last time I was doing this was with v7.2.  I was checking how to reverse engineer a window with European rating conditions so that WINDOW shows the correct results using EU ratings, switch to NFRC ratings (check how much SHGC and U-values differ for interest sake) and then export the IDF code from WINDOW for e+.

I checked values with a spreadsheet to follow if the edge of glass parameters were sane. Everything checked out okay.

I had used Therm as a pre-process only if no values were available for the frame. Also then I didn't get crazy values.

Something is going wrong in your THERM calculation. I would focus there.

Am 02.11.2017 1:30 nachm. schrieb "'Edward G. Lyon' eglyon@xxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx>:

 

The procedure is to model window frames and glass in THERM first, bring the results into WINDOW and then make a window in WINDOW.  One of the reports you can generate is direct .idf text for E+, though I used to use the reference file input.  I used to have problems with single glaze windows which I could work around.  Turns out that there is often sufficient heat loss from the frame through the edge of glass to make the edge of glass look less conductive than center of glass. (too much brain power behind programming and not enough calculation experience) This problem is different and seems to be related to any frame system you model  yourself.

 

Iâ??m trying to reinstall version 6 and try again?have had several issues with the 7 recentlyââ?¦

 

Ned Lyon, P.E. (MA, WV)
Staff Consultant

SIMPSON GUMPERTZ & HEGER

781.907.9000 main
781.907.9350 direct 
617.285.2162 mobile 
781.907.9009 fax

www.sgh.com

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From: EnergyPlus_Support@yahoogroups.com [mailto:EnergyPlus_Support@yahoogroups.com]
Sent: Thursday, November 02, 2017 8:16 AM
To: EnergyPlus_Support@yahoogroups.com
Subject: Re: [EnergyPlus_Support] LBNL Window IDF Problem

 

 

I always did THERM first and used those values in WINDOW. Are you doing it the other way around?

 

2017-11-01 23:45 GMT+01:00 'Edward G. Lyon' eglyon@xxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@yahoogroups.com>:

 

We are using LBNL WINDOW 7.5 and THERM 7.5 to generate .idf input for windows in EnergyPlus (as we have done numerous times before with other versions of the program).  In WINDOW we have reasonable values for glass and frame conductivity, but when we export an .idf using our THERM frame calculation we get a value of 500 w/m2-K for frame conductance (ok, sometimes it is 499.999969).  Using any of the default WINDOW frame entries returns a reasonable frame conductance value in the .idf.

 

Anyone else experience the same or know where to find a solution or know who better to ask?

 

Ned Lyon, P.E. (MA, WV)
Staff Consultant

SIMPSON GUMPERTZ & HEGER 
     | Engineering of Structures and Building Enclosures

41 Seyon Street, Building 1, Suite 500
Waltham, MA 02453

781.907.9000 main
781.907.9350 direct 
617.285.2162 mobile 
781.907.9009 fax
www.sgh.com

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Posted by: Jean Marais <jeannieboef@xxxxxxxxx>

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