We have lived in our home for 7 years and have had to replace four windows because the inside panes crack and spider (usually during winter). They are double-hung thermopanes with a full screen on the outside. It happens to different windows; three in the back bedrooms, and one above the kitchen sink. Is there any logical explanation for this? What can be done to prevent this from happening to other windows?
Thermally insulated glass should not crack unless there is some type of manufacturing or installation defect. The only windows that I have seen crack did so because they were twisted or under pressure in the frame. A small amount of pressure applied to one point can cause a crack.
In this case, I would follow up with the manufacturer and their local representative. Major manufacturers stand behind their products and often offer a 10-year warranty on thermally insulated glass. There is no logical reason for glass to randomly break except the issues listed.