The Okna 500 Series ESP double hung  energy savings package with triple pane glass is a very popular choice. 

  • 30% Better than Energy Star┬« minimum
  • 1500% Better AI rating than Industry Standard!! (Significantly lower Air Infiltration)
  • 3┬╝" Deep welded frame curved colonial exterior a beautiful, strong long lasting performance.
  • Heatseal┬« warm edge spacer drastically reduces the possibility of condensation on the inside of the window.
  • Full integral interlock with double weather-stripping.
  • Chooses the Auto-Lock feature for security.
  • Matching colors on our fully extruded handles.
  • Factor installed fiberglass mesh half screens.
  • Optional locking screen for added security.
  • Perfect double hung for new Construction or as a replacement window.
  • All Okna windows are custom made for a great fit and look.
          Energy Star Comparison To
Glazing Option U-Value SHGC VT CR Minimum* Energy Star Minimum
Triple Glazed              
With ESP 0.21 0.26 0.43 70 0.30 30% Better


      Industry Comparison To  
  Our Windows Minimum Industry Minimum  
AAMA Rating R50 R15      
Air Infiltration cfm/ft2 0.02 0.3        1500% Better
Water Penetration mph   54 33           64% Better  
Structural Integrity mph 171 94           82% Better