Thermal shutters

Claim 1

In a window assembly having a sash portion with glazing therein and a casing surrounding said sash portion, the improvement comprising a thermal insulating system having: a continuous single sheet of relatively compliant material bonded to itself at spaced intervals to form a plurality of adjacent elongated cells arranged in a double row configuration and disposed adjacent to but spaced from said sash portion on said casing, said double row of elongated cells having generally coplanar outer portions collectively forming a pair of generally parallel outer thermal insulating members and having coplanar inner portions collectively forming a common intermediate thermal insulating member spaced between and generally parallel to said outer thermal insulating members, thereby providing a quadruple glazing insulating effect with the glazing in said sash portion, attachment means for securely affixing said formed continuous single sheet to said window assembly on said casing, said attachment means including batten means fixedly secured to said casing for fixedly pressing and sealingly affixing the edge portions of said formed continuous single sheet between said batten means and said casing thereby reducing infiltration through said window assembly and providing a double row of insulative dead air spaces within said elongated cells over the full area of said window assembly.