International Glazing Database Knowledge Base

Table of Contents

GENERAL INFORMATION

What is the International Glazing Database (IGDB)?

The International Glazing Database (IGDB) is a publicly available collection of data for more than 1000 glazing products from manufacturers all over the world. Each record contains detailed spectral optical data, thermal data, structural details, description and product information. The data is sufficient to design glazing systems and windows and perform accurate energy performance calculations.

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How is the IGDB maintained?

The Windows and Daylighting Group of the Lawrence Berkeley National Laboratory (LBNL), with the support of the U.S. Department of Energy*, performs technical review of product data originating in the U.S. LBNL also updates and maintains the database file itself. The WinDat Network, with support from the European Commission, performs technical review of data originating in Europe.  The Japanese Glass Manufacturers association is considering performing technical review on glass originating in Asia. The Australasian Window Council performs technical review on glazing originating in Australia. The database could not exist of course without the support of the glazing manufacturers themselves who measure and format the spectral data and provide additional product information. The manufacturers also play a critical role in peer review of all data.

*This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, State and Community Programs, of the U.S. Department of Energy, under Contract No. DE-AC03-76SF00098. 

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Why does the IGDB have two formats?

The IGDB currently exists in two formats: a single database-format file and an older collection of text files. The recommended database format has many advantages for applications in terms of speed, content, and functionality, such as sorting and searching. It is currently used by Optics 5.1 and WINDOW 5.1. The older text-file format is still required by WINDOW 4.1 and other programs. Support for text-file format is discontinued since April 1, 2003.

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Where can I get the IGDB?

Although the IGDB is a separate entity, it only has meaning with one of the software programs that use it. You will have to use one or more of these programs to view the data, create new windows, etc. By downloading the latest version of Optics or Window you will automatically get the latest version of the IGDB.

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What software do I need to use the IGDB?

Any database needs an application to extract the information that it contains. The following specialized glazing and window design applications can each read, display, and use the information in the IGDB with varying degrees of utility.

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It looks like Window and Optics use their own copy of the IGDB, is that correct?

Yes, this is (partly) correct. Both Optics and Window install their own copy of the IGDB on your computer, but the spectral data in the two databases is identical. The reason for this is that Optics uses some extra information in the database, that is not used by Window, to enable the user to construct new glazings or deconstruct existing glazings. Furthermore, Window allows the user to save new data to the database, but Optics uses a separate database to store user generated data.

When you update your Optics database and Window database correctly, you will always have the latest and identical version of the IGDB for use with both programs.

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Why is the database password protected?

The data in the IGDB has gone through a rigorous review process. In order to maintain the integrity of the data, the database is protected by a password and some other mechanisms in order to avoid (accidental) tampering with the data.

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WINDOW 4.1 Information:

Window 4.1 is no longer supported (as from April 1, 2003). The text files database is no longer updated.

PRODUCT DATA

I would like to use the spectral data of a certain product but it is not in the database. Where can I get this data?

We do not control what data is submitted to the database. Data is submitted by the manufacturers of the products. If you would like to use the spectral data of a specific product and you know the manufacturer, please contact the manufacturer and request them to submit the data to the IGDB. Submission of data to the database is for free!

When the manufacturer is willing to submit the data they should contact us and we will provide them with the information about the data submission procedure.

Note: you can never submit data of a product that you do not own. If you want to use some spectral data for your own private use, please refer to the documentation of the software programs that you use.

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I would like to model glass with scattering properties (such as diffusing glass, glass with frits, etc). Is there any data for such glazings in the database?

The IGDB currently contains only data for non-scattering glazings because all of our optical calculations are based on that assumption.

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I created a data file for submission to the IGDB and tested it by importing it into Optics. This failed, creating a very general error. Is my data file incorrect?

Optics is in some aspects more strict and in some aspects more strict than the requirements that are put on data submitted to the IGDB. When your data is exactly in the format described by the data submission requirements, the data will probably import fine into Optics, where you have to keep the following in mind:

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What is the maximum number of wavelengths in a data file?

The number of wavelengths is currently limited to 1000 wavelength points.

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FORMAT

What do the designations 'front' and 'back' mean? Is this the same as position #1 and #2? How does it relates with the surface positions in an IGU?

'front' and 'back' reflectance Rf and Rb are arbitrary designations simply used to distinguish the reflectance from each side of a glazing in the spectral data. The position and orientation of a glazing in an IGU determine how these values match up to surface positions #1, #2 - the relationship of Rf/Rb to surface position cannot be standardized because some coatings can be used in more than one position (for example). When spectral data is used to simulate a glazing system using Optics or WINDOW, each glazing must be oriented correctly by the user (use the 'Flip' command to change the orientation of a layer / swap Rf and Rb values). The correct position and orientation for a glazing can be checked by taking note of the position of any coatings (illustrated by a dashed line in Optics and WINDOW) and/or by checking the reflectance values of each surface. The product literature from the manufacturer of the glazing can help to establish the most appropriate orientation for a given glazing.

If you are preparing spectral data, we recommend that you choose a convention for defining Rf and Rb that will be consistent throughout your own data. Some companies always use Rf to denote the reflectance of a coated surface, some companies always use Rf to mean the surface closer to the exterior, and Rb to mean the surface closer to the interior when the glazing is oriented in its 'usual' manner so that simulators rarely have to 'flip' the glazing when simulating it. Any convention that makes good sense to you is acceptable.

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TROUBLESHOOTING

WINDOW5 can't open full database, glazing.mdb file

If you get the following message when trying to import records from the full IGDB file, called glazing.mdb, into the WINDOW5 Glass Library the glazing.mdb file may be set to Read Only.

 In Microsoft Windows Explorer, go to c:\Program Files\LBNL\LBNL Shared, right click on the file, click on the Properties choice at the bottom, and in the Properties dialog box, uncheck the "Read Only" box if it is checked. Close the Properties dialog box and try reimporting

Error Message -- Not a valid password when importing IGDB Update records into the WINDOW Glass Library

If you leave the Format set to "Window 5 Database" and then browse to the IGDB Update.mdb file, you will get an error message saying "Not a valid password"