Thanks for the advice, le, you're probably right. But I can't afford to get my patio door replaced with low-e glass, so I guess I'll try the cheap stuff and see if it helps. I do have a vertical blind in that door, and I close it in late afternoon in the winter. In summer, I keep it closed or partly closed during the heat of the day. I do get a lot of solar heat gain through that glass, and I debated whether I want to give that up, but there are a lot more times when I would be losing heat than gaining heat, with cloudy days and night time, so I think I will really be ahead by putting on the window film. I have put a decorative film on the top section of the palladian window in the living room, and this goes on the same way, so I think I can manage it all right. I'll just do it sometime when I don't expect to get interrupted, and take my time about it. Maybe one day next week.
