DOE-2 File -- Overall & Center-of-Glass U-values Identical
In the "Overall and Center of Glass Ig U-values" section of the DOE2 file generated by WINDOW, the Overall and Center-of-Glass values are both identical, and are both the Center-of-Glass values. The report does not contain the Overall U-value of the product. DOE2 does not need that value, as it calculates it's own U-value for every time step, so this bug does not produce inaccurate results in DOE2.

Import Glass Layers from IGDB or Optics5 User Database

Import Glass Layers from the IGDB or IGDB Update

or

Import Glass Layers from Optics5 User Database: In WINDOW5, in File/Preferences, go to the Optical Data tab, and set the second option, Optics5 User Database, to your Optics5 user database (which by default is called UserGlazing.mdb, but it can have any name with the "mdb" extension) -- you can browse to the file with the browse button (its default location is in Program Files\LBNL\LBNL Shared directory). In WINDOW5, go to the Glass Library List View, click on the Import button, select "IGDB or Optics User Database" as the format, and click OK.  The program will open the user database set in the File/Preferences dialog box (the name will be displayed at the top of the dialog box) and you will see the glass layers that can be imported in to the existing library. You can select the records you want to import (use Shift Click to select contiguous records, Ctl Click to select multiple non-contiguous records, or Select All to select all records). Then click the Select button, which will import the selected records into the Glass Library.

 

Program Crash at Startup

If you see the following error message upon startup of WINDOW5, you may have a conflict with your computer's video driver that prevents WINDOW5 from displaying correctly. 

WINDOW5 uses OpenGL which is a component of DirectX to generate the program graphics.

To fix this problem, try the following:

• Download and install the latest version of Microsoft DirectX (from the Microsoft DirectX page:

http://www.microsoft.com/windows/directx/default.aspx?url=/Windows/DirectX/downloads/

• If that doesn't help, try to find a more current display driver for the graphics card (from the card vendor) in your computer.

Exporting WINDOW 4.1 Spectral Data Text Files from WINDOW 5

	Go to the Glass Library List View
	Select the records to export from WINDOW5 to WINDOW 4.1 spectral data file format
	Click on the Export button
	Select the radio button "Selected Records"
	Set Format to "Window 4"
	Click on the OK button
	The files will be saved into the directory where the WINDOW 5 database is located. The name of the files will be the same as the "Name" field in the WINDOW 5 Glass Library.
	Copy (using Microsoft Windows Explorer or other method) those files into the WINDOW 4.1 W4Lib\SpecDat directory (or whatever directory structure set up by the user for WINDOW 4.1).
	Some of the newer glass library file names are not in the old WINDOW 4.1 "8 character name, 3 character extension" format, and so will need to be renamed (in Microsoft Windows Explorer or other method) before being added to the WINDOW 4.1 Glass Library
	In WINDOW 4.1, go to the Glass Library
	Do Add, New, then type the ID number to use (keep it the same as that in WINDOW5 for consistency)
	Type the name of the file, exactly the same as the name of the file moved into the SpecDat directory, press the Enter key (don't enter any of the values for the glass layer).
	Press Esc to get out of Edit mode
	Add more as necessary
	When you have finished adding all the desired records and are no longer in Edit mode, do Update, type the record numbers to update, and WINDOW 4.1 will look for the filenames specified, and update the values based on the files it finds in the SpecDat directory, including the # if it was assigned in the WINDOW 5 database.

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UV Transmittance values reported in WINDOW

WINDOW reports three different values in the whole window report for transmittance:

	Tdw-K
	Tdw-ISO
	Tuv

Tuv (TUV in the Standards file) is the unweighted transmittance over the ultraviolet. Because it is unweighted by a "detector" function, TUV has no correction for the spectral sensitivity of materials to radiation damage. It doesn't even cover the spectral range in which damage occurs, just the "uv" meaning below the visible. This function is included for historical comparison purposes only, since many manufacturers used this function before corrected functions were available. It is believed to have little meaning.

Tdw-K (TKR in the Standards file) is weighted by the old Krochmann damage function which purports to correct for the sensitivity of many materials. While more meaningful than TUV, it is also included for "historical" purposes, because it was included in ISO 9050 and perhaps in CEN standards before the latest recommendations by CIE.

Tdw-ISO (TDW in the Standards file) is weighted using a function recommended in the CIE standard which also derives from the work of Krochmann, but is considered to have more general validity. We had the opportunity to harmonize with CIE when the NFRC standard was last updated and we took it.

WINDOW 5.2 database

Download WINDOW 5.2 clean database (a zip file called W5.zip, 14 MB, which contains W5.mdb with IGDB version 16.3) in case you have a corrupted database (W5.mdb). This file is normally located in the WINDOW 5.2 program directory, which defaults to
c:\Program Files\LBNL\WINDOW5. If you already have a W5.mdb file in that directory, you should rename or move it before copying this file. Otherwise, the older database will get overwritten.

FIXED BUGS:

Tilted Products:
In the Window Library, when you input a value into the Tilt field, the program does the appropriate thing for calculating the Condensation Resistance value, according to the following rules:

	For window tilts greater than 90 degrees, CR simulation results are used for sills, headers, and horizontal mullions, U-factor simulation results are used for jambs and vertical Mullions
	For window tilts less than 20 degrees, U-factor simulation results are used for all cross sections
	For window tilts > 20 and < 90, CR is not calculated and a warning message appears

Calculating Multiple Records in the Window Library List View:
The program was not calculating the results properly from the Library List View if multiple records were selected for calculation and the Frame or Divider THERM files had changed. This has been fixed. 

Relative Heat Gain in List View of Glazing System Library: 
In the Glazing System Library List View, the Relative Heat Gain is always in SI units.

Calc Problem Using Glass Library NFRC ID Greater Than 32000: 
If a glass layer is imported from the Optics User Database with an NFRC ID greater than 33000, when that glass layer is used in a glazing system calculation, the program will say that the layer has been deleted and will not complete the calculation. The work around is to use NFRC ID values less than 32000.

VT1 Calculation With Dividers is Incorrect:
In the Window Library Detailed View, the VT1 calculated value (accessed from the Detail button next to the VT results) is incorrect if dividers are modeled. 

EnergyPlus Output File Problem for Gas Definition:
The file generated for the EnergyPlus program (generated from the Window Library) contains lines in the Gas Data section that are more than the 132-character limit in the EnergyPlus routine that reads the file. The file is too long because of extra spaces between the labels in the heading line, as well as the data in the line following the heading. The work-around is to edit the EnergyPlus file and delete extra spaces. Only one space between each value or label is required.

EnergyPlus Output File Problem for Uncalculated Record:
The file generated for the EnergyPlus program (generated from the Window Library) may contain wrong values if the file is generated on a record in the Window Library that has not been calculated (i.e., there are "?" in the Results section). If the EnergyPlus file contains values such as "1.#IO" or "0.0" for values that should not be zero, close the EnergyPlus file, and click on the Calc button for the record.

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KNOWN BUGS:

Error Message during Calc due to decimal point of ",": 
WINDOW 5.0 will display an error message while doing a "calc" in the Glazing System Library if the computer's regional settings have the decimal point set to ",". To fix this, go the the Microsoft Windows Control Panel, click on Regional Settings, and go to the Numbers tab. Change the Decimal Point choice to a "." 

Importing THERM file into WINDOW generates "unnamed file has a bad format" error message: 
If importing a file into WINDOW generates the error message:

"Unnamed file has a bad format"

this means that there is a problem with the THERM file, in that the file results are spanning a buffer when being read. One work around to try is to add comments to one of the input fields in the File/Properties menu -- it shouldn't take more than 15 characters.

Environmental Conditions -- Kimura convection model not working
In the Environmental Conditions Library Convection section, one of the "Model" options is "Kimura". This model calculates the Convection Coefficient based on "Inside Air Velocity" and "Air Direction". The program correctly calculates the convection coefficient based on this model, but when that Environmental Condition is then used in the Glazing System Library, the program uses a convection coefficient based on an air velocity of 0. A work around for this bug is to calculate the convection coefficient using the Kimura model, and then input that coefficient into the Fixed Convection Coefficient model, which does work properly. 

Documentation for the Kimura model can be found in the following references:

1. Kimura, K., 1977. Scientific Basis for Air Conditioning, Chapter 3, Radiative and Convective Heat Transfer, pp. 93-94, Equations 3.41 to 3.44, Applied Science Publishers, London.
2. Ito, N., K. Kimura, and J. Oka, 1972. A field experimental study on the convective heat transfer coefficient on exterior surface of a building, ASHRAE Transactions, Vol. 78, Part 1.
3. S. Shakerin (1987). Wind-Related Heat Transfer Coefficient for Flat-Plate Solar Collectors. Journal of Solar Energy Engineering, May 1987; 109; pp. 108-110.

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Environmental Conditions -- Fixed Combined Coefficient Bug
In the Environmental Conditions Library Convection section, if the Model is set to "Fixed combined coefficient", the fields Effective Sky Temperature (for U-factor Outside) and Effective Room Temperature (for U-factor Inside), both of which are hidden for this model, may be set incorrectly. The work around is to temporarily set the Model to "Fixed convection coefficient" so that the fields are visible, set them to the "Inside Air Temperature" value for the U-factor Inside tab and to the "Outside Air Temperature" value for the U-factor Outside tab, then set the Model back to "Fixed combined coefficient".

The example below is for the U-factor Outside tab - repeat the steps for U-factor Inside tab also.

Fixed Combined Coefficient -- Effective Sky Temperature field does not show	Change the Model to Fixed Convection Coefficient and the Effective Sky Temperature field shows. Check to see that it has the same value as the Outside Air Temperature
If the Effective Sky Temperature is not equal to the Outside Air Temperature, change it so they are the same	Change the Model back to Fixed Combined Coefficient after changing the Effective Sky Temperature to be equal to the Outside Air Temperature

Exporting One Glass Record to a WINDOW5 Database:

When you export one glass layer into a new WINDOW5 database (MDB) file, open the new database from within WINDOW5, and then try to open the original WINDOW5 database, the program will show 'no current record' and other error messages. The work around is to quit the program, ignore all the messages that come up, and restart the program and open the original WINDOW5 database.

Glazing System Non-Convergence Error Message

There are some circumstances where WINDOW 5 will give the following error message:

Click here for a detailed explanation of the problem and the work-around for getting the glazing system to calculate.

CAUTIONS:

Importing THERM files:
THERM 5 files should now have the exterior frame boundary conditions tagged with a U-factor tag of SHGC Exterior, which calculates the exterior wetted length of the frame for the Solar Heat Gain Coefficient calculation in WINDOW 5. If that tag is not present in a THERM 5 file imported into the WINDOW 5 Frame Library, a message will appear at import time saying:

This means that the program will use the Frame U-factor tag length for this calculation, which is on the interior of the profile. To do the calculation correctly, tag the THERM 5 file with the SHGC Exterior U-factor tag.

Window Library

	CI calculations: these have been implemented but WINDOW5 does not detect whether the THERM files were modeled with the CI feature turned on in THERM. Therefore, it is up to the user to model the THERM files with both the CI and radiation enclosure features implemented.
	Environmental Conditions Check: Currently the program does not do a consistency check between the environmental conditions used in the glazing system and those used in the window.

Glass Library

 

	"#" Disappears: WINDOW 5.1 and the International Glazing Database version 12.4 have a new "checksum" feature for the spectral data. This checksum will determine whether a set of spectral data is valid. If it is, the "#" will be displayed, and if it is not, the "#" will not be displayed. An older WINDOW 5.1 Glass Library that is loaded into the current version of WINDOW 5.1 will not have the checksum values on the spectral data files, and therefore the "#" will disappear. To fix this, reimport the glass record from the latest IGDB or the W5.mdb default database that came with the official program installation.
	Glass Library List Displays 0s and 1s: Sometimes the values in the Glass Library will display as 0s and 1s rather than the appropriate values. Opening another library and then coming back to the Glass Library will sometimes fix this.
	Importing Records from Optics5 UserGlazing.mdb file: When creating a record in the Optics5 user database (which is the UserGlazing.mdb file by default), make sure to make the NFRC ID non-zero, ideally a number greater than 9999 and less then 32000 so that existing records in the Glass Library will not be overwritten.
	NFRC ID Correction on 10/14/2002: On 10/14/2002, the Optics IGDB and the WINDOW Glass Library database were corrected because four Guardian records had the incorrect NFRC ID. The following table lists the correct NFRC ID and the filename for these four glass layers. Correct NFRC ID Filename 3134 SG52C6.GRD 3135 SG52G6.GRD 3138 SGSR20C6.GRD 3139 SGSR20G6.GRD If your WINDOW 5 Glass Library does NOT have these ID and filename combinations, you need to update your glass library. The best way to update your glass library is to download a "clean" version of the W5.MDB database (this file has IGDB 14.2): http://windows.lbl.gov/software/window/52/w5mdb.zip  (10 Mb Zip file) If you unzip this file in the WINDOW program directory (c:\Program Files\LBNL\WINDOW5), it will overwrite the existing W5.MDB. If you have modified your W5.MDB file and do not want it overwritten, you can unzip the corrected W5.MDB file into another directory, and import the four Guardian glass records from the corrected database into your database.
	Message on Import: Can't find dominant wavelength for purewhite This message will appear when importing the ONE.DAT file from the IGDB (International Glazing Database) into the WINDOW5 Glass Library. It is information only, and does not mean there is a problem with the record or the database. So basically, click OK and ignore it.

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ALGORITHM CHANGES FROM WINDOW4.1 TO WINDOW5:

WINDOW5’s calculations for U-values, SHGCs, and visible transmittances will be a little different than those from WINDOW 4.1. These small differences are due to the fact that WINDOW5’s algorithms have been updated to reflect the best known practices for determining window thermal and optical properties using computer simulations. These improvements also make WINDOW5 consistent with the latest ISO and ASHRAE standards (currently in draft form) on this subject. These standards are the results of many years of work by the international community and incorporate several improvements to WINDOW 4.1’s algorithms developed a decade ago.

Specific algorithms which have changed which influence U-factor calculations:

	gas properties and gas mixtures have been updated
	an improved gap heat transfer correlation is used
	an improved interior film coefficient results in noticeable changes for single glazed windows with changes becoming less significant the more insulating the glazing system

SHGC and Visible Transmittance calculations are impacted by the above changes. They can also be significantly impacted by the use of a different (global not direct) solar spectral irradiance function, as recently approved by ISO TC160. This means the sun is represented by direct and diffuse solar radiation not just direct radiation. For glazings which transmit evenly across the solar spectrum (clear glass) this will not lead to a noticeable change. For glazings which transmit selectively in the solar spectrum (such as green glass or some low-e coatings), solar and/or visible properties may change by up to 0.04 or so.

Finally, as discussed in the Program’s manual, WINDOW now offers interior surface temperature maps and Condensation Resistance (CR) calculations. These are new features and calculation procedures for them are evolving with NFRC and other groups.

More Details

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