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Pella® Impervia® Fiberglass Double-Hung Window

Mulled

Two Pella Impervia mulled double-hung windows are joined together in the factory and shipped as one unit. This creates a dramatic window opening in the home, doubling the size of a single window. Each window features two sashes that raise and lower independently for ventilation. These fiberglass windows are resistant to water, wind and outside noises — while delivering energy efficiency, security and ease of operation. The durable powder-coat finish resists chalking, fading and scratching.

  • Two fiberglass double-hung windows combined side-by-side in the factory.
  • Commercial grade strength and performance.15
  • Sashes tilt in so you can clean both the interior and exterior of the glass from inside your home.
  • Product #401001

Configuration: 2-wide

Talk to a Pella Rep for Pricing

Pella Impervia Double-Hung Window Features

Design Options

Solid-Color Frames

    • black fiberglass frame

      Black

      • brown fiberglass frame

        Brown

        • white fiberglass frame

          White

          • morning sky gray fiberglass frame

            Morning Sky Gray

            • tan fiberglass frame

              Tan

            Pella Impervia Double-Hung Window Specs & Install Details

            • Timeless style and proven performance with unmatched strength and lasting durability
            • Handles the most extreme heat and cold9
            • Interlocking checkrail creates a barrier for air and water infiltration
            • Double-hung windows available in sizes up to 47-1/2” x 79-1/2”
            • Performance class and grade LC30-LC50

            Frame
            • Nominal wall thickness of Duracast fiberglass composite members is .050" to .080" thick.
            • Frame corners are mitered, joined and bonded with corner locks and mechanically fastened with injected polyurethane adhesive.
            • Frame has 10° slope sill.
            Sash

            All sash members have mitered corners bonded with corner locks and sealed with injected polyurethane adhesive.

            Weatherstripping
            • Fin-type pile on jambs, top rail and stile of upper sash
            • Vinyl-wrapped foam at sill on frame and bottom rail of lower sash.
            Glazing System
            • Quality float glass complying with ASTM C 1036.
            • 11/16" insulating glass sealed and bonded to sash.
            • High altitude glazing available.
            Hardware
            • Galvanized block-and-tackle balances connected to sash with polyester cord and concealed within the frame. 
            • Two locks are installed on units 37" wide or greater.
            • Locks are zinc die-cast, self-aligning cam action factory-installed on the interlocker to match finish. 
            Additional Hardware options
            • Optional limited opening device available for field installation on vent units in foamed PVC to match interior of unit; nominal 3-3/4" opening.
            • Device allows window to open less than 4” with normal operation, with a release mechanism that allows the sash to open completely. Complies with ASTM F2090-10.

            Frequently Asked Questions

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            contemporary dining room with black impervia windows

            Pella Impervia

            When it comes to performance, Pella Impervia is an overachiever. Windows with dual-pane glass offer energy-efficient options that will meet or exceed ENERGY STAR® guidelines in all 50 states.1 Further increase your energy efficiency with optional foam insulation.

            With outstanding resistance to water, wind and outside noises while increasing energy-efficiency, security and ease of operation, Pella Impervia windows are an excellent choice for your home.

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