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OKNA 420 Performance - Sliding Windows

OKNA 420 Sliding windows deliver top-of-the-line performance at prices that are pleasing to most budgets.  They're marked by their quality design and craftsmanship, clean yet modern lines, and easy to open and close functions.  Moreover, the 420 Series offers significant energy-efficiency on par with windows that cost twice as much.  Get the perfect union of performance, style and sustainability with Wonder Saver windows in Western NY.

Like all OKNA Series windows, the 420 Wonder Saver sliding windows are custom built to order, based on the specific size, color and dimensional requirements of your home or building.  Wonder Windows also offers a full selection of window accessories, including hardware, locks, handles and more.

okna 420 sliding window

OKNA 420 Series

  • Exceptionally strong fusion-welded mainframe design
  • Enhanced thermal efficiency from Heatseal® warm-edge spacing
  • Designed to minimize moisture formation and condensation
  • Comes with factory-installed mesh half-screens
  • Dual weather strip protection enhances comfort and energy efficiency
  • Can be upgraded with locking screens for better security
  • Wonder Windows offers expert professional installation
  • NFRC U-Factor: 0.28  Air Infiltration: 0.01  Solar Heat Gain: 0.29
Overview - Options & Accessories - Performance

Performance Options Available - Precision Weld 

**         Energy Star Comparison To
Glazing Option U-Value SHGC VT CR Minimum* Energy Star Minimum
Dual Glazed            
with ESP 0.28 0.29 0.53 62 .030 7% Better than  ENERGYSTAR®
Deluxe  0.27 0.29 0.53 62 0.30   10% Better than ENERGYSTAR®
Triple Glazed            
with ESP 0.22 0.25 .042 70 0.30 27% better
Deluxe 0.21 0.25 0.42 70 .030 30% better
Deluxe/ Krypton 0.17 0.25 0.42 73 0.30 43% better
U-Value, SHGC, VT, CR values may slightly change for windows made with GBG (Grids Between Glass)
  • SHGC - Solar Heat Gain Coefficient
  • VT - Visible Transmittance
  • CR - Condensation Resistance
  • Deluxe - ESP & Foam
  • * Northern Climate Zone
** Okna Industry Comparison To
  Our Windows Minimum Industry Minimum
AAMA Rating   R35 R15  
Air Infiltration cfm/ft2 0.01 0.3 3000% Better
Water Penetration mph 56 33 79% Better
Structural Integrity mph 143 94 52% Better

Water Penetration mph - Specifies wind load pressure in mph a window can withstand without leaking, under rain equivalent to 8" per hour. Structural Integrity mph - Wind load in mph a window can withstand before breaking.

All results numbers are based on tested window sample by NFRC & AAMA testing window guidelines. Use for comparison purposes only. Actual values may vary depending on installation, size of the window, and other conditions.