Call us at
1-800-219-5332
Contractors Join Our Network

Window Consumer Infomation

Abcleads.com BBB Business Review   Member of NAHB

Current Board Posts

  • Sunday December 14, 2014

    Single Picture/Single Hung Hybrid to Two Double Hungs

    How involved would it be for an installer to remove one large (approx.) 64X66 window that consists of a center single hung and...

  • Thursday December 11, 2014

    Thermal Industries vs Okna in WI

    Looking at getting some replacement windows in Waukesha, just outside of Milwaukee. I have a quote for Thermal Industries and one for Okna,...

  • Tuesday December 9, 2014

    Glass Breakage

    That would more than likely be a "stress" crack. Either wind or temperature caused a fault in the glass to become a crack....

  • Saturday December 6, 2014

    What is the best energy efficient window for Dallas Texas

    Hi,
    I live in the Dallas-Ft Worth Texas area and need to replace 5 arched windows in the front of my house which...

  • Wednesday December 3, 2014

    Window Replacement Options

    I posted this on another forum before I found this replacement window specific forum. I know some people there also post here,...

  • Tuesday December 2, 2014

    Another need help with windows choice, Vytex, vs Soft-Lite..

    So I was set on Sunrise Vanguard windows, but the only seller in town messed up my order twice and was somewhat more...

  • Wednesday November 26, 2014

    How do I make this window square?

    I just installed my first replacement OKNA window. I took my time, checked for plumb level and square (or so I thought). Everything...

  • Sunday November 23, 2014

    Replacement window over very thin aluminum frame

    I am installing my first vinyl replacement window over an aluminum frame (stucco wall). In all the instructional videos and the instructions that...

  • Saturday November 22, 2014

    Reynolds Vinyl Window

    I purchased Reynolds Vinyl Windows in 1996 and they have condensation in most of them. I was told to get the model number...

  • Thursday November 20, 2014

    Warranty question

    Do lifetime/double-lifetime warranties for the best vinyl manufacturers (like Okna) typically cover only the product or do they cover labor as well? For...

1 of 10

Do it Yourself- Replacement Window Video

 

Rating Window Efficiency Systems

 

When looking at different models of windows you want to be cognizant of the rating that the manufacturer applies. That rating will either be a “U Value” which gives an indication of that windows tendency to transfer heat either in or out, or by an “R Value” which describes the windows resistance to transferring heat in or out.

U-Values are a measure of heat conductance

R-Values are a measure of heat flow resistance

 

If a window's R-value is high, it will lose less heat than one with a lower R-value. Conversely, if a window's U-value is low, it will lose less heat than one with a higher U-value. In other words, U-values are the reciprocals of R-values (U-values = 1/R-value). NOTE: Most window manufacturers use R-values in rating their windows.

Usually, window R-values range from 0.9 to 3.0 (U-values range from 1.1 to 0.3), but some highly energy-efficient exceptions also exist.

When comparing different windows, you should ensure that all U- or R-values listed by manufacturers:

  • Are based on current standards set by the American Society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE)
  • Are calculated for the entire window, including the frame, and not just for the center of the glass
  • Represent the same size and style of window

5 factors affecting the R-value of windows

  1. The type of glazing material (e.g., glass, plastic, treated glass)
  2. The number of layers of glass
  3. The size of the air space between the layers of glass
  4. The thermal resistance of conductance of the frame and spacer materials
  5. The "tightness" of the installation (i.e., air leaks-- see previous discussion).