Commonly Used Abbreviations
Additional definitions and terminology may be found in NFRC 600: Glossary and Terminology.
– National Fenestration Rating Council – a nonprofit research/educational
organization (501(c) 3) that develops and administer energy-related rating and
certification programs that serve the public by providing fair, accurate, and
credible information on fenestration performance.
– Approved Calculation Entity: An individual, who has attended an NFRC
Calculation Training Workshop, completed and passed all necessary examinations,
and has obtained a Certificate of Approval which qualifies him or her to carry
out performance calculations of fenestration products for certification using
the Component Modeling Approach.
AM – Air Mass: The ratio of the mass of atmosphere along the actual
observer-to-sun line to the mass that would exist if the observer was at sea
level, at standard barometric pressure, and if the sun was directly
overhead (at the zenith).AMC – Attachment Manufacturer’s
APC - Accreditation Policy Committee: A
standing committee whose members are appointed by the NFRC Board of Directors
to manage the NFRC Laboratory Accreditation Program (LAP). See the NFRC 710:
Operating Policies Manual for further details.
APD – Applied
Films Product Directory
– Accredited Simulation/Testing Laboratory: Computer simulation or testing
laboratory that has met NFRC Laboratory Accreditation Program (LAP)
requirements, has entered into a NFRC laboratory License Agreement, and
received a NFRC Certificate of Accreditation, none of which has been revoked.
– Compliance and Monitoring Program: NFRC administers this program that
monitors program activity and assists and educates architects, builders, code officials
and other regulatory agencies. The governing document for this program is the
– Certification Agency Program: NFRC administers this program which includes a
set of rules and procedures by which an independent certification and inspection
agency becomes licensed and operates. The governing document for this program
is the NFRC 702.
CEAP – Calculation Entity Approval
Program: NFRC administers this program
that contains the rules and requirements for becoming an Approved Calculation
Entity (ACE) and ACE Organization in the CMA Program. The governing document for this program is
the NFRC 708.CMA
– Component Modeling Approach: A new rating methodology being developed by NFRC
to address fenestration in commercial buildings.
CMA PCP – Component
Modeling Approach Product Certification Program: NFRC administers this program
which contains the rules and requirements for component
manufacturers/participants seeking spacer and frame component approval and
Specifying Authorities seeking product certification by requesting a CMA Label
Certificate. The governing document for
this program is the NFRC 705.
CMAST CPD –Component Modeling Approach Software
Tool Certified Products Directory: A
freely accessible, web-based directory administered by NFRC that provides
energy rating information for non-residential fenestration products as well as
NFRC-approved components, and a listing of all CMA Label Certificates.
CPC – Certification Policy Committee: A standing committee whose members are
appointed by the NFRC Board of Directors to manage the NFRC Certification
Agency Program (CAP) and to provide interpretations for the NFRC Product
Certification Program (PCP). See the NFRC 710: Operating Policies Manual for
– Certified Products Directory:
A directory of fenestration products in electronic form, listing fenestration
products and their performance ratings, for which product certification
authorization has been granted by a licensed IA (inspection agency), and can be
searched by the public.
CPD Number – Certified
Products Directory Number: A
unique identification number assigned by NFRC via the CPD to an authorized
CTS – Calibration Transfer Standard: An insulation board that is faced with glazing, instrumented with
temperature sensors between the glazing and the insulation board core, which is
used to calibrate the surface heat transfer coefficients and the surround panel.
FMC – Fenestration Manufacturer’s Certificate: An FMC may be used by a manufacturer under specific conditions in
the event that a properly applied NFRC temporary label has been removed, or at
the manufacturer’s discretion upon request from a responsible party (i.e.,
building code official, builder, homeowner, etc.)
Products that fill openings in a building envelope, such as windows, doors,
skylights, curtain walls, etc., designed to permit or limit the passage of air,
light, vehicles, or people.
Attachment – A device (such as, but not limited to,
shades, films, or blinds) designed to be physically attached to, incorporated
with or covering a fenestration product.
Film -- Fenestration attachment products which consist of a flexible adhesive-backed
polymer film which may be applied to the interior or exterior surface of an
existing glazing system. See Fenestration Attachment.
HTDD – Hybrid Tubular Daylighting Device: A
tubular daylighting device (TDD) whose light transmitting tube consists of more
than one material and/or has more than one geometry throughout its length. Typically used with suspended ceilings or to
illuminate spaces without ceilings.
IA - Independent Certification and Inspection Agency:An
organization or person authorized by license to conduct specified services for
the Certification Program.
IAC – Inter-Agency Comparison: Organization,
performance, and evaluation of certification authorization processes by two or
more certification agencies in accordance with predetermined results and/or
IG/IGU – Insulating Glass Unit: A preassembled unit comprising lites of
glass, which are sealed at the edges and separated by dehydrated space(s). The
unit is normally used for windows, window walls, picture windows, sliding
doors, patio doors, or other types of fenestration. (SIG – Sealed Insulating Glass Unit)
ILC – Interlaboratory Comparison: Organization,
performance, and evaluation of the same test sample or simulation by two or
more laboratories in accordance with predetermined conditions.
IRC – Individual-in-responsible-charge: The
individual(s) responsible for assuring that the quality of services offered and
provided by an Licensed Certification Program are in full compliance with the
NFRC 700, NFRC 702, and NFRC 705. An IRC shall participate in any workshops
associated with the NFRC 702.
IRV -- Identical Rating Values
The Independent Verification Program: A requirement because of NFRC’s status as
an approved Certification Body (CB) for the ENERGY STAR ® Windows Program. This is
a program that will verify the performance ratings of ENERGY STAR-qualified fenestration products sold in the market that agrees
with the performance ratings listed in the NFRC Certified Products Directory.
This program will use procedures that complement the inspection and validation
testing requirements of the NFRC 700. Full implementation
is anticipated to begin January 2013 upon the approval of the Board.
KD – Knocked Down Product: A fenestration product supplied by a licensed
manufacturer/responsible party in an unassembled or partially assembled state,
which requires further assembly at the jobsite.
– Laboratory Accreditation Program: NFRC administers this program which
contains the rules and requirements for licensed, accrediting thermal test and
computer simulation laboratories. The governing
document for this program is the NFRC 701.
OAVA – Outdoor Air Ventilator Assembly: An
apparatus independent from but installed into a fenestration product for
controlling the transfer of air through the product.
OWL – Outdoor Wetted Length: Measured from
the interface between frame and glazing to the first adiabatic boundary on the
– Product Certification Program: NFRC administers this program which contains
the rules and requirements for licensed manufacturers/participants to label
windows (and responsible parties to produce Label Certificates). The
governing document for this program is the NFRC 700.
– Relative Humidity: The
ratio of the amount of water vapor in the air compared to the maximum amount of
water vapor that the air could hold at a particular temperature and pressure.
SIRC – Simulator-In-Responsible-Charge: The
individual(s) responsible for assuring that the quality of services offered and
provided by an Accredited Simulation Laboratory are in full compliance with the
LAP. An SIRC shall have successfully completed an NFRC Simulation Accreditation
Workshop, passed an NFRC Simulation Accreditation Examination, attended an NFRC
Annual Accreditation Workshop, and participate in any ILC evaluations in
accordance with the LAP.
Site-Built Program – A rating program
developed in 1999 by NFRC to rate non-residential fenestration products.
TB - Thermally Broken Members: System members with a minimum of 5.30
mm (0.210 in) separation provided by a thermal break.
TI - Thermally Improved Members: System members with a separation ≥
1.60 mm (0.062 in) provided by either a thermal break or open air space that
may be interrupted by short thermal bridges between the
interior and exterior surfaces.
Daylighting Device: A non-operable device primarily designed to transmit daylight from a
roof surface to an interior ceiling surface via a tubular conduit. The device
consists of an exterior glazed weathering surface, a light transmitting tube
with a reflective inside surface and an interior sealing device, such as a
translucent ceiling panel. See also
"Hybrid Tubular Daylighting Device.”
NFRC Energy Performance Ratings
AL- Air Leakage: The volume of air flowing per unit time per
unit area through a fenestration system due to air pressure or temperature
difference between the outdoor and indoor environment. (NFRC 400).
– A relative indicator of a fenestration product's ability to resist the
formation of condensation at a specific set of environmental conditions. The
higher the Condensation Resistance value the greater the resistance to the
formation of condensation. (NFRC 500).
SHGC – Solar Heat Gain
Coefficient: A rating that expresses the percentage of incident solar heat
transmitted through a fenestration product; the lower the SHGC, the less solar
heat gain (NFRC 200 and NFRC 201).
Transmittance: A rating that expresses the rate of heat flow through the
fenestration product. The lower the
U-factor, the less heat is allowed to transfer through the fenestration product
(NFRC 100 and NFRC 102).VT– Visible
Transmittance: A rating that expresses the percentage of visible light
transmitted through a fenestration product (NFRC 200).