Multi-layered film window system

Abstract

A high R-rating window assembly storing multiple, reciprocating reflective flexible film layers defined by one or more parallel, displaced films or looped films define the layers. The layers are contained in a sealed housing between rigid transparent (e.g. glazed) layers. The glazed layers are separated on the order of 3 to 5-inches and are secured to low thermal conductivity framework pieces. The framework is capped with a motorized roller and film housing and the assembly is evacuated and filled with a desiccated, inert dry gas. Several plastic, reflective coated films are supported under tension in planar parallel relation between the glazing layers from the motorized roller and several guide rollers and guide tracks. Location sensors responsive to indicia on the films identify film position. Temperature sensors monitor ambient, internal and user set thermal conditions to control film exposure. The films are operable via a room control system and window controllers to define open, closed and partial exposure conditions. Alternative control functions may control film exposure in relation to room occupancy.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to energy efficient windows and, in particular, to a sealed window having a plurality of suspended films or film surfaces and controls to extend and retract the film(s) to control thermal efficiency. [0002] Energy loss through glazed surfaces comprises a significant part of a building's total energy loss, and can typically approximate 50% of the total loss. These losses occur during the heating season as a consequence of a low insulating rating and outward heat flow, mitigated by the solar gain of any windows and walls exposed to the sun. During the cooling season, inward solar heat flow detracts from the insulating characteristic of the building walls and windows, unless shading is employed. [0003] Attempts to improve the thermal transfer properties of glazed surfaces and particularly to decrease heat loss through glazed surfaces have in the past primarily consisted of shutters over the outer surface, for example, woo...

AI Technical Summary

Benefits of technology

The invention is a sealed window assembly with multiple moveable film surfaces mounted in planar relation to each other and displacing glazing panels. The window is filled with a desiccated air or noble gas, and includes a primary film support roller with optical control circuitry. The window assembly incorporates several improvements over existing window wall systems and provides better insulation, reduced convection, and a low thermal conductivity. The film layers are each preferably comprised of a mechanically strong and smooth plastic substrate, and both surfaces are coated with a suitable material to provide a low-emissivity surface that is also high in solar reflectance. The invention also includes a plurality of metalized, coated or clear film layers that can be interdigitated or interlaced with each other in parallel, displaced, interlocking alignment over portions of their respective travel paths.

Problems solved by technology

These losses occur during the heating season as a consequence of a low insulating rating and outward heat flow, mitigated by the solar gain of any windows and walls exposed to the sun.

The consequent rather bulky cover further precludes the application of such covers to curtain-wall structures, such as large buildings.

It is also difficult to construct such covers to be weather tight, movable, and reliable.

The effectiveness of internal covers is limited by a combination of factors including high infrared emissivity, air convection within the room spaces and leakage of air around and through window and wall surfaces.

None of them, however, have produced structures yielding R-values approaching that of a frame wall.

Some of these patents propose the use of metallized films or fabrics to decrease infrared emissivity to perhaps 0.3, but the structures suffer from problems of dust build-up and the necessity to frequently clean the surfaces and consequent vulnerability to damage.

While this “beadwall” approach has provided windows having reported R-values of the order of 20, several limitations exist.

The beads occupy significant storage space when the windows are emptied.

The glazing surfaces in contact with the beads tend to become covered with dust and statically suspended particles over time.

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