International Glazing Database
- Material types: Samples must be flat and specular.
If the samples are diffusing or light redirecting rather than specular they
are excluded from the IGDB and cannot be properly treated in Window5.
Diffusing or light redirecting materials may be acceptable however under
the new experimental procedures for the CGDB and Window7. Specular materials
may be monolithic or have a thin-film coating such as a low-emittance or
solar-control coating. They may consist of multiple layers as in a laminate
or flexible film applied to a glass substrate.
- Properties to be measured: Measurement of
transmittance and reflectance must be made over the solar spectrum from
300-2500 nm wavelength using a commercial spectroradiometer equipped with a
suitable integrating sphere in accordance with NFRC 300. The reflectance in
the thermal infrared must also be measured from at least 5-25 micron in
accordance with NFRC 301. If the material is of a known type such as clear
(i.e., uncoated) window glass, a default value may be used.
- Who can measure: The
submitter is typically the glazing manufacturer or independent, third party
measurement lab. In either case, the measuring entity must participate in
comparison (ILC) to qualify.
LBNL is not a commercial measurement lab and does not perform routine,
service type measurements. LBNL has a research grade instruments and will
perform measurements for research purposes or for questionable data
resolution purposes or to establish baseline for an ILC. See list of qualified measurement
- Additional information: The submitter must
provide the name, appearance, structure and thermal conductivity of the
- Formating the data: The
submitter must be able to put the data into the proper format for review and
eventual inclusion in the IGDB. Some test labs can provide this service if
the primary source of material is not able or not inclined to do it
- Composite products: Properties of a
composite material such as a laminate have been calculated from component
data using the Optics5 program when all the properties of all the component
materials are in the IGDB
If you think that you can provide data under the above
conditions then you should read further and familiarize yourself with the
details of the process. Questions
about these requirements and all other IGDB related matters should be addressed
Qualify to measure
Before the submission process can begin, the laboratory
producing the data must successfully participate in an interlaboratory
comparison (ILC) conducted by LBNL. The participating laboratory may be a
commercial measurement laboratory or the manufacturer's own in-house lab. If a
participant obtains new equipment, assigns a new operator, or simply desires to
check compliance, the ILC may be repeated at any time.
Choose your sample
The manufacturer is responsible to select and measure a
representative sample for the product. Properties
of a representative sample:
- A random sampling of the sold product should have
properties equal to, or both higher and lower, compared to the
The selected sample must be stored for at least four
There is no specified method to choose your sample, but the
burden of proof would be on the submitter in the case of a question during peer
review or later, so it pays to make a careful choice to avoid more work later.
Perhaps for a particular product confidence in quality control is so high that
any sample would be as good as any other. On the other hand, the safest and most
scientific method would be to do a statistical survey or average over many
samples from different factories and different production runs.
The product must be flat
and the surfaces must be parallel.
Furthermore the product must be specular in the solar
(300-2500 nm) wavelength range. Specular
glazings scatter very little light on transmission as well as reflection.
The easiest way to
determine if a product is specular is by using visible inspection, if it looks
milky or hazy it is not specular. If you can see a clear and undistorted image
through it the product is specular. For the UV and near infrared range a
spectrophotometer with an integrating sphere can be used assuming the sphere has
a specular exit port. If the ratio between diffuse and total transmittance is
less than 0.05 it can be considered specular. The same procedure holds for
Applied film and laminate manufacturers should submit
their products on clear glass substrates, preferably 3 mm low-iron, to minimize
any influence the substrate has on the submitted data.
Measure the properties
The solar optical properties (300-2500 nm) shall be
characterized in accordance with NFRC 300.
The infrared properties (5-25 micron)
shall be characterized in accordance with NFRC 301.
Those documents are available at http://nfrc.org/technicaldocs.aspx
Format the data
After measuring the spectral transmittance and the spectral
reflectance from both sides of the sample, as specified above, all three
datasets are combined into a single file for submission. The format of the data
file is well defined and conforms to the long-standing Window5/6 text file
format. Templates are
provided for each type of accepted glazing material.
please do not submit files with names
containing more than 30 characters (including the extension) File
extensions -- at this time, it is not possible to change the file
extensions. We plan to implement this capability in the future, but
for now, it is necessary to continue to use the file extensions
Caution: There are many instances in these
examples which contain the word "reference" in the title. The first- time
data submitter is advised to avoid these data types for now. They refer to
cases which can be "deconstructed" in Optics5 and then recombined with other
components to calculate the properties of a variant on the original glazing.
See the general warning
on calculated data. This entire section will be rewritten here with
proper instructions for safe use of "reference" files.
Submit for review
First time data submitters should provide the following
- A file extension for your files. This extension
cannot be changed at this time. All your data files should be submitted with
this file extension.
- The number of products you intend to include in
IGDB. We assign a block of ID numbers to each manufacturer. This block
cannot be expanded at this time so please choose this number very carefully.
Each data file should contain the NFRC ID number in the
header. The ID number must be selected from the manufacturer's assigned rage of
If a manufacturer’s data is to be submitted by a
third party, and the third party will be listed as the Manufacturer in
the IGDB, in essence “re-branding” the product, the third party must
have the product measured and submit it to the normal IGDB review
process independent of any submittals under the original manufacturer’s
name. The submittal must indicate, for each product submitted,
the original product manufacturer.
In addition, the third party must obtain permission
from the original manufacturer for both submitting the data and for
re-branding the product. This permission must be submitted to
Lawrence Berkeley National Laboratory (LBNL) in the form of a letter
from the original manufacturer, on their company letterhead, listing the
products that will be re-branded. If the manufacturer has submitted data
to the IGDB under their own name, this letter must come from the
manufacturer’s IGDB contact. This letter (or letters if the products are
from multiple manufacturers) must accompany the data submission forms.
In the case where the manufacturer wishes to discontinue having the
re-branded product in the IGDB, another letter from the manufacturer
must be submitted to LBNL.
Pay fees to NFRC if applicable
At this time NFRC requires payment of fees only for
products that are intended to be used in NFRC window property simulations and
ratings. If data is submitted directly to LBNL, the intent of the data provider
to obtain NFRC ratings will be determined and NFRC will be so informed. NFRC
approved files will be so marked in the IGDB. The fee
schedule is available on
the NFRC website. This policy may be changed at any time at the sole discretion
Review and acceptance
This final stage consists of waiting for
the review to quietly conclude. Sometimes there are questions from the LBNL
internal reviewers or the peer reviewers that require checking and
resubmission of data. All data submitters automatically become members of
review group and
will receive emails with data that is being considered for the next IGDB
update. This is not meant to be a test or an impediment, but a cooperative
process leading to proper submission of accurate data. The requirements on
technical review, peer review and quarterly publication intervals are given
302, Sections 3.5-3.8. Each
submitter is given a reserved
block of NFRC ID numbers.
There are going to
be six IGDB releases per year. Data submitters should follow the schedule
below for their data submission. Due to shorter processing time, we will no
longer accept more than 100 submissions or requests for
modification/change from each manufacturer, in each cycle.
Data goes to Peer Review
End of Peer Review