U.S. DOE R-5 Program

Mercury Excelum is a proud participant in the U.S. Department of Energy's volume purchase program for R-5 windows. Mercury Excelum "R-5 windows"—highly insulating windows with a whole-window R-value of 5 (a U-value of around 0.2)—are some of the most thermally efficient windows available today.  Vinyl replacement windows from Mercury Excelum are designed specifically to provide you with windows that lower your home energy bills and make your home significantly more comfortable to live in.

What is an R-5 Window?
R-5 windows are highly insulating windows with a whole-window R-value of 5 (or a U-factor of around 0.2) and are the top tier of energy-efficient windows for cold and mixed climates available today.

What is an R-value and U-factor?
An R-Value is the measurement of heat loss through a window. The higher the R-value, the more efficient the unit is in preventing heat loss through the opening. U-factor is the inverse of R-value. U-factor is the measurement of heat transfer in Btu/hr-sq ft-°F. So, the lower the U-factor, the better the thermal performance of the unit.

What Mercury Excelum products currently qualify for the R-5 volume purchase program?

Mercury Excelum Harmony Series Triple Pane Windows including

• Double Hung
• Slider
• Casement
• Picture
  The above products are both available for new construction applications as well when ordered with an Integral Fin and J
  

How do I purchase Mercury Excelum R-5 Windows?
At the time of order, Mercury Excelum customers must specify DOE R-5  Qualifying Windows. Homeowners are encouraged to contact their dealer/installer or contact  Mercury Excelum for a contractor  nearest their location and request highly insulating R-5 windows.  For more information on purchasing Mercury Excelum R-5 windows, contact Mercury Excelum today.