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NFRC CPD: National Fenestration Rating Council Certified Product Designation number

U.S. Climate Zones (view maps here):
  S = Southern
  S/C = South-Central
  N/C = North-Central
  N = Northern
  Door ES N & N/C = Doors meeting ENERGY STAR requirements in Northern & North-Central climate zones
  Door ES All States = Doors meeting ENERGY STAR requirements in all U.S. climate zones

Canadian climate zones for 2015 have been re-identified as 1, 2 and 3. View maps here.

U-Factor (or U-Value): The lower the U-factor, the greater a window's resistance to heat flow and the better its insulating value. Units are Btu/(hr•ft2•ºF).

Imperial U-Factor vs. Metric U-Factor – Imperial U-Factor is used in the U.S.A. Metric U-factor is used in Canada. An equivalency chart is available with the ENERGY STAR Canada information.

SHGC: Solar Heat Gain Coefficient Total is a unitless number representing the ratio of radiant solar energy passing through/ incident solar radiation. A small SHGC is desirable during summer. This includes the effect of frame and dividers, which have SHGC of almost zero. Shading Coefficient = SHGC / 0.86.

VT: Visible Transmittance of the total fenestration product system is the transmittance across the visible portion of the solar spectrum where sensitivity to each wavelength is weighted by the eye's response. VT is expressed as a dimensionless number from 0 (completely opaque) to 1.0 (completely clear). This value is influenced by the glass selection and by the ratio of glazing and frame area. Vtc high number (Ø.65) means nearly clear view, and low Vt total number means tinted view.

CR: Condensation Resistance = How well a window resists the formation of condensation on the inside surface, expressed as a number between 1 and 100. The higher the number, the better a product is able to resist condensation.

Glass Pane Type: Definitions for the lami glass codes (Ex: Lami 20) are available from your local dealer.

PDL: Performance Divided Lite bars are a divided lite option using one lite of glass; i.e., they are visual divisions in one insulating glass unit rather than separate units which are used for true divided lites.

Combo: Combination storm/screen unit

Ratings for products with obscured or wired glass and/or stained glass shall be deemed to be equivalent to the ratings for clear glass.

Many Kolbe products meet or exceed various ANSI/AAMA/NWWDA 101/I.S.2-97, 101/I.S.2/NAFS-02, Canadian CSA 440-00, AAMA/WDMA/CSA 101/I.S.2/A440-05 reformed ASTM E1886 and E 1996 standards, Florida Statewide Approval system, and the Texas Department of Insurance system, etc. Visit the websites of these organizations: AAMA | ANSI | ASTM | Canadian CSA | ENERGY STAR USA | ENERGY STAR CANADA | FL Building Code | NFRC | TDI | WDMA