Have You Considered Up-grading Your Single Glazed Windows?November 14th 2006
Consider replacing single glazed windows with high performance windows. Major technological changes extend beyond glass itself to low-conduction spacers and frames. In the average home with conventional windows half the heat loss through windows goes out the cracks; much of the rest goes straight through the panes and frames.
Don't confuse standard double glazed windows which cost about 8% more but are twice as effective. Triple glazed are twice as good again. Low-emissivity windows (known as low-E) use an almost invisible metal coating to reduce heat loss, reflect outside heat in summer and block ultraviolet light which fades draperies, carpets and furniture. Best of all: two low-E panes with an insulating gas like argon between them. i.e. Smart Glass Low E with argon gives an R-value of 4.17
Budget first for your homes biggest problem areas: north facing windows (heat loss), large south facing windows (sun traps in summer) or windows in line with the prevailing winter wind.
Choose window shades and blinds backed with an insulated material. For best results look for three factors: vapour barrier, reflective surface and a device that creates a tight seal with the window frame.
Install energy efficient window and skylight film which allows light transmission while blocking heat and glare.