Stop right here and consider this top of the line rated sliding window from the Okna 500 series. Look at the performance ratings on this window and compare it to other sliding window that cost mush more. The Insul-Tec 500 triple pane Deluxe with krypton gas delivers everything you could ask for in any window.
  • 47% Better than Energy Star® minimum
  • 333% Better Air Infiltration protection than Industry Standards.
  • Triple pane glass with krypton
  • Foam filled frame
  • 3¾" Depth Welded Mainframe with superior strength long lasting performance.
  • The Heatseal® warm edge spacer system provides excellent thermal efficiency 
  • Full integral interlock with double weather-stripping.
  • Optional Auto-Locking system
  • Heavy gage fully extruded handles 
  • Factory installed Fiberglass mesh half screens come standard on all windows
  • Great for Replacement and New Construction applications
  • Available in 2-lite and 3-lite choices
  • Available grids between glass in Common Grid Patterns
          Energy Star Comparison To
Glazing Option U-Value SHGC VT CR Minimum* Energy Star Minimum
Triple Glazed              
Deluxe/krypton Gas 0.16 0.26 0.42 74 0.30 47% Better


      Industry Comparison To  
  OKNA Windows Minimum Industry Minimum  
AAMA Rating  R40 R15      
Air Infiltration cfm/ft2 0.09  0.3 333% Better
Water Penetration mph    59  33   79% Better  
Structural Integrity mph  153  94   63% Better