I bought 2 Indows for my basement windows in an attempt to reduce my condensation problems in our cold Canadian winter. I cannot be happier! So far, in temperatures of -15 to -20C, the Indows are holding the condensation and ice formation on windows in check. I can also reduce the time I need to run my dehumidifier (so saves on electricity bills!). Installation could be made a little bit easier, though I think it is because our windows are imperfect and have a slight inclination, so getting the corners of the Indows pushed into the window frames were a bit challenging. Just don't give up, and you'll not regret it.