NFRC 200
Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence
| Organization: | NFRC |
| Publication Date: | 1 January 2004 |
| Status: | inactive |
| Page Count: | 29 |
scope:
Products Covered
A. Products of all frame materials including, but not limited to, aluminum, steel, thermally broken aluminum, wood, vinyl, reinforced vinyl, fiberglass, and plastic, used independently or in combination.
B. Products of all operator or unit types i including, but not limited to, vertical sliding windows, horizontal sliding windows, casement windows, projecting windows, fixed windows, non-standard shaped windows, glazed wall systems, glazings for site built fenestration products, bay or bow windows, and skylights.
C. Single or multiple assemblies of exterior doors.
D. Products of any size.
E. Products of all glazing materials, tints, and types, including, but not limited to, clear glass, tinted glass, laminated glass, thin plastic films (internally suspended, internally applied, or externally applied), rigid plastics with or without any solar control, low-E or any other partially transparent coating.
F. Products with any or no gap width between glazing layers.
G. Products with any gas-fill between glazing layers, including, but not limited to, air, argon, krypton, CO2 or mixes of these gases.
H. Products with any spacer or spacer systems between glazings, including, but not limited to, metallic, non-metallic or composite spacers.
I. Products utilizing any and all glazing dividers, including, but not limited to, interior, exterior, or between glazing grilles, muntin bars, true divided lites or simulated divided lites.
J. Products designed for installation at any tilt.
K. "Film" 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 in an installed
fenestration product (i.e., as a retrofit, 'field-installed' or
'daylight-installed'
[Note 2.: Films factory-applied to glazing prior to fenestration product fabrication and installation are already covered as glazing options by NFRC 200 and shall not be rated according to the procedure of Section 5.7.]
Products Covered using NFRC 201 Test Procedure for SHGC
Products not covered by NFRC 200 simulation techniques and that are covered by test only procedures are as follows:
A. Products with shading systems between the glazing layers of the fenestration aperture.
B. Products with non-specular transmittance and reflectance properties, including, but not limited to, translucent fiberglass and glass blocks.
C. Fenestration systems whose glazing departs from being parallel, such as with curved glazing, complete bay windows, corrugated or patterned glazing or glazing blocks. (Fenestration systems made up of combinations of complete windows or doors each of which individually meets the requirements in Section 2.1 can be included by treating each of the windows or doors separately.).
D. Tubular daylighting devices.
E. Garden or greenhouse windows.
F. Adhesive-backed film products with non-specular transmittance and reflectance properties, including, but not limited to, opaque, textured, translucent or 'frosted' films.
G. Adhesive-backed film products with non-uniform properties across their surface, including, but not limited to, patterned films.
PURPOSE
To specify a method for calculating Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT) at normal (perpendicular) incidence for fenestration products containing glazings or glazing with applied films, with specular optical properties calculated in accordance with ISO 15099 (except where noted) or tested in accordance with NFRC 201.
[Note 1.: This standard specifies a method for calculating the solar heat gain and visible transmittance from direct solar radiation through most fenestration products at normal incidence only. This procedure is limited to normal incidence calculations because solar optical data needed for such calculations is typically only available at normal incidence. While solar radiation rarely enters a fenestration product at normal incidence, solar heat gain coefficients and visible transmittance at near normal angles of incidence (less than 30 degrees off normal) are typically very similar to those at normal incidence; for other angles, the solar heat gain coefficients and visible transmittance at normal can be used, to first order, as an indicator of the relative magnitude of solar heat gain and visible transmittance.]
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