Even if you have old, drafty windows, you can cut down energy loss by using cost-effective thermal window coverings.
Standard window blinds have an insulating value of only R-1. The best way to insulate your windows is using several layers of window dressings.
Using shades, sheers and especially heavier draperies with insulated linings can dramatically cut back on heat loss – raising the R-value of a single-pane window from R-1 up to R-6!
Instead of a typical vinyl pull-down shade, take a look at the new "honeycomb" or "cellular" shades made of fabric. The air pockets provide an extra layer of insulation, blocking up to 62 percent of the heat transfer through the window pane.