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NFRC 100 Site Built (Commercial)
This site is developed and maintained by Quality testing Inc. to provide up to date information to Architects and to the glazing industry concerning Code Compliance using NFRC 100 (site built) procedures and general information about NFRC 100. This site is maintained for your use, if you have any questions please feel free to e-mail them to: info@qtitest.com .
INTRODUCTION:
NFRC Site-Built certification is a specialized part of a voluntary national rating system for fenestration products which specifies methods for determining the thermal transmittance of (U- Factor), Solar Heat Gain (SHGC) and Visible Light Transmittance (VT) of site built fenestration products.
What is NFRC and why are they making me label?
What codes require or reference NFRC 100?
Who is responsible for Certification and Labeling?
How do I comply with the Energy Code?
Should I do this if it's not required?
So I have a project with Energy code requirements what do I do?
What is NFRC and why are they making me label?
The NFRC (National Fenestration Rating Council) is a national voluntary organization established in 1989 to develop a national, uniform energy rating system for windows, doors, skylights and other fenestration products.
NFRC 100 is a PROCEDURE for determining "U" Factors and Thermal performance characteristics such as Solar Heat Gain (SHGC) and Visible light Transmittance (VT) for site built products.
The requirement for a product to be "NFRC Labeled" is mandated by local, state, or national energy codes, NOT NFRC. Oftentimes, certification and labeling is prat of the architectural specs. It is up to you watch for statements like “Shall meet all applicable state and local codes.” This could mean that you will need NFRC Certification.
The NFRC label carries the simulated "U'" Factor, SHGC and VT for the total product sample (both frame and glass). The Total Product "Ratings" are based on NFRC specified sizes to allow easy comparison of products from different manufacturers. The label may also carry an NFRC Air Leakage rating.
The NFRC Label for Site Built Products takes the form of a project specific " Site Certificate". In other words, there is a single project site label which can be used as "proof" of certification rather than having to label every window or piece of glass.
Field Glazed or Field assembled glazing systems such as glazed wall systems, sloped glazing, storefronts or window walls. Typically the framing and glass are from different suppliers. It is usually not appropriate for the factory assembled windows or doors which are used in residential OR commercial applications although there has been some discussion on allowing building over 3 stories high and over a certain square footage to also use the “Site Certificate”. So check for updates from NFRC or local specifiers. The procedure has been applied to systems with standard glazing components as well as translucent panel systems and even glazed systems incorporating perforated metal plates.
NFRC 100 certification has been part of the Non- Residential portion of the Washington State Energy Code since 1994. NFRC 100 is also one of the required methods for compliance with the AB 970 Energy Efficiency Standards For Residential and Nonresidential Buildings modifications to the 1998 California Energy Commission Energy Efficiency Standards adopted by the California Energy Commission January 4, 2001. NFRC Certification is also referenced in the Model Energy Code, International Energy Conservation Code and the ASHRAE/IES Energy Code for Commercial and High-Rise Residential Buildingsand may be required by any jurisdiction adopting these codes.
How Do I comply with both the Energy Code and the Specification?
Energy code compliance details vary with each state and jurisdiction, so check with local building officials. That said, Energy code compliance is often an "envelope" compliance calculation and as such the "U" Factor, SHGC and possibly the VT are specified by the owner or architect on the project. In many cases the glass to be used is also specified by others so the framing system is the main component that the glazing contractor has any control over when determining the total product "U" Factor and SHGC values. This makes the selection of the framing system a critical part of the bidding and code compliance process. The best strategy is to know ahead of time how your favorite systems perform. This can usually be accomplished by doing preliminary simulations with a few glass combinations which will give you a range of performance values.
Who is responsible for Certification and Labeling ?
For site-Built products anyone involved in the process can take responsibility for Certification and Labeling. Typically the glazing contractor has ultimate control over the final assembly of the glazed wall or sloped glazing components and does the Certification and Labeling. The standard allows any of the other contractual parties ( for instance, The Gazing Contractor, the Building Owner, Architect or the supplier of the system frame extrusion) to take on the responsibility if they wish.
Should I do this if it's not required?
The U-Factors and Solar Heat Gain Values obtained from the NFRC Certification Program are usually lower than the values in the default tables contained in the codes, which can result in lower job costs. On a major project the cost of the simulations and validation tests should be much less than the potential cost savings. Keep in mind that in most codes the default values are definitely punitive.
In addition, if a "U"-Factor and SHGC are specified during the bid process and you don’t know that you can meet the specification, your potential liability could be significant.
So I have a project with Energy code requirements what do I do?
QTI has been working with the Washington State Non-Residential Energy Code for many years. This code is the first non-residential code to use NFRC compliance requirements and in many ways is beginning to serve as a model for other jurisdictions. In our experience, many projects can reach compliance without going through the NFRC process. If you have a project that is subject to code compliance requirements we suggest that you take the following steps.
FIRST collect the following information from the plans and specifications:
What "U" Factor is required?
What Solar Heat Gain Coefficient (NOT the same as shading Coefficient) is required?
What Visible Light Transmittance ( if any) is required?
What glass combination is specified?
With this Information available:
STEP ONE
Check the local code for allowable default tables for "U" Factor and SHGC. If they exist, do the specified glass and frame type default values meet the specification? If so, you need only comply with your local or state requirements for proper identification and documentation for your project.
For California projects that fall under the Nonresidential section of Title 24, Part 6 there is an alternative method of calculation that may be used. Contact the California Energy Commission for details and/or download the Title 24 Nonresidential Manual.
STEP TWO
If the default values do not meet the specified value check with your linear supplier
In some cases the linear supplier may have done some or all of the work to have the simulations and testing done to certify the product. In this case it is usually possible to use this work for your specific project at very little cost.
STEP THREE
If steps one and two are not possible should you perform a pre-bid simulation to ensure that your system meets the specification. Contact Quality Testing Inc. , an NFRC Accredited Simulation Laboratory, for guidance in this process.
With the help of the laboratory:
a) Determine the "category" (curtain wall, window wall, sloped
glazing, etc. ) your product falls into.
b) Supply all the required information to your laboratory including elevations, section drawings and die drawings.
NOTE: Curtain walls are simulated and tested with intermediate verticals as jambs and intermediate horizontals as head and sill.
Sloped glazing and Windowwalls are simulated and tested with the standard head, sill and intermediate verticals as jambs.
ALL UNITS ARE 2000mm X 2000mm (79" X 79" nominal) TWO LITE UNITS.
c) Supply additional glazing and/or spacer options that you might want to qualify. It is generally easier and cheaper to qualify additional options at the time of initial simulation. This will provide you with answers you need now and possibly in the future for other projects.
d) Have the NFRC simulation performed.
STEP FOUR
If the simulation shows that the system meets the requirements, bid the project. Ideally you should give yourself a "cushion" as far as meeting the project specification values. If you maintain a cushion, small design changes that may occur will be less likely to cause the system "U" Factor and/or SHGC value to exceed the project requirements.
STEP FIVE
A validation test will be required using the same extrusions and sizes that were used for the simulation. There is normally enough time between the time contracts are awarded and actual construction starts to have the validation test performed and submitted to an Inspection Agency (IA) for certification Authorization.
STEP SIX
Instruct the simulation and testing laboratory to submit the reports to an Inspection Agency (IA) of your choice. The IA will determine if the submitted reports meet all of NFRC's requirements. If all requirements are met, they can issue a Site Built label certification form for the project. For further information about IA's and the NFRC Process go to the NFRC Web site.
ã Quality Testing, Inc. 2000
Quality Testing, Inc. Updated 06/12/2007
3310 Hill Ave WEBMASTER
Everett, WA 98201
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