I had Thermal Gard replace my windows in the 1990's and after about ten years have lost there argon between the glass panels. They have become very cloudy and are an eye soar to the house. I contacted Thermal Gard and was told they no longer warrant the windows after ten yrs of ownership. For about $85 each they would send new panels, I don't think so. I just wanted to pass the information along to anyone who is thinking about Thermal Gard. I wouldn't recommend them if you plan on living in the house for any length of time. I have planned on replacing them with Pella. I've had Pella in my front room since 1984 and they look as good as they did when installed.