The ESP (energy saver package) double hug 400 double hung means what it says. For homeowners who need a beautiful and energy efficient replacement this is a very good choice. 

  • 27% Better than Energy Star┬« minimum
  • Fully welded welded beveled frame and sash  that is very durable 
  • One of the top windows in the 400 series for energy efficiency 
  • Heatseal┬« warm edge means lower condensation on the window.


          Energy Star Comparison To
Glazing Option U-Value SHGC VT CR Minimum* Energy Star Minimum
Triple Glazed              
With ESP 0.22 0.26 0.43 68 0.30 27% Better


      Industry Comparison To  
            Our Windows Minimum Industry Minimum  
AAMA Rating (38 x 63)   R50 R15      
Air Infiltration cfm/ft2   0.05 0.3  600% Better
Water Penetration mph   56 33   70% Better  
Structural Integrity mph   171 94   82% Better