Cambridge Performance Data

Thermal Performance Air, Water & Structural Performance Glossary
Thermal Performance Double-Hung (Clear, Double-Pane) 47-1/4x59 Single-Hung (Clear, Double-Pane) 47-1/4x59 Double-Hung (Solarban 60 Low-Conductance Spacer, Argon Gas Fill) 47-1/4x59 Single-Hung (Solarban 60 Low-Conductance Spacer, Argon Gas Fill) 47-1/4x59
Total Unit U-Value1 0.48 0.48  0.30 0.30
Visible Light Transmittance2
  Grids
  No Grids

 

0.53
0.59

 

0.52
0.58

 

0.47
0.53

 

0.46
0.52

Daylight Transmittance3 81% 81%  72%  72%
 Tdw-ISO4 0.743  0.743  0.559  0.559
 SHGC5
  Grids
  No Grids

 

0.49
0.55 

 

0.49
0.55

 

0.26
0.28

 

0.25
0.28

Condensation Resistance6  47  47  56 60

1 Windows tested per NFRC 100. Data applies to double-pane insulated glass using a double-strength glass with 1/2" airspace.
2 Tested using GED's Intercept(R) ULTRA low-conductance warm-edge spacer system. Calculations provided by Lawrence Berkeley Laboratory Window 5.2 and Optics5 software based on 3/4" IG unit.
3 Daylight transmittance measures the performance of glass only.
4 International Standards Organization Damage Weighted Transmission Rating (Tdw-ISO) calculations performed by Lawrence Berkeley Laboratory 5.2 Windows software and is weighted using recommended International Commission on Illumination (CIE) standards.
5 Solar Heat Gain Coefficient (SHGC) tested in accordance with NFRC 200. This value varies by style, glazing system and grids.
6 Condensation resistance is tested in accordance with NFRC 500. 

 

For a complete PDF listing of all window styles and related performance, please click here.

Air, Water & Structural
Performance
Double-Hung
48x72

Single-Hung
48x72

Double-Hung Oriel
48x72
Single-Hung Reverse
Oriel 48x72
Triple Double-Hung
48x72
Overall Grade Rating  R50 R55  R40  R30  R50 
Structural Rating  50 55  40  30  50 
Water (PSF)  7.52  8.36 7.52  6.06  7.52 
Total Unit Air Infiltration
@ 25 mph 
0.10 CFM  0.07 CFM 0.06 CFM 0.03 CFM 0.10 CFM
Test Method AAMA/WDMA/
CSA 101/I.S.2/
A440-05 
AAMA/WDMA/
CSA 101/I.S.2/
A440-05  
AAMA/WDMA/
CSA 101/I.S.2/
A440-05  
AAMA/WDMA/
CSA 101/I.S.2/
A440-05  
AAMA/WDMA/
CSA 101/I.S.2/
A440-05  
Mulled Unit Size n/a  n/a n/a  n/a  145x72

 

Glossary

Condensation Resistance Factor: Calculated from the interior surface temperature of a window when the window is subject to a standardized set of temperature and humidity conditions. The higher the number, the better the ability of the window to resist condensation. This AAMA test is voluntary with a minimum standard of 35 for thermally improved windows.

Daylight Transmittance: The measured amount of visible light transmitted through glass.

International Standards Organization Damage Weighted Transmission Rating (Tdw-ISO): Quantifies the ability of a glass package to reduce fading by measuring the effects of both ultraviolet and visible light.

Low-Emissivity (Low "E): Glass coated with a microscopically thin metallic layer that allows the short wave light energy to pass through as it blocks long wave ultraviolet and infrared solar energy by reflecting it back toward its source (toward the outside in summer and toward the inside in winter).

Overall Grade Rating: Code that designates style of window, recommended application and the window's performance grade which is also the window's design pressure in pounds per square foot.

Solar Heat Gain Coefficient (SHGC): Measures the amount of radiant heat transfer from the sun through a window. The lower the number means the less amount of solar heat transfer through the window (lower is better in the south).

U-Value: The rate heat flows through a product for each degree of the temperature difference between one side and the other. The lower the U-value, the greater a window's resistance to heat flow and the better its insulating value.

Visible Light Transmittance: A relative amount of visible light transmitted through a fenestration product (including the frame which has no visible transmittance) with theoretical range from 1.00 to 0.00. The smaller the number, the less visible light is transmitted. The higher the number, the greater the contribution to daylighting potential.