I have a window that slides to the side, and each time temperature outside drops below 0*C it freezes and there is no way to open it (not that there is ice all over it, just moisture from the room freezes somewhere inside I guess). Are there any (easy) solutions to prevent freezing or making it open when needed?
My suggestion would be to pull out the window and clean everything really well to make sure nothing is gumming things up. Then I would use a clean rag and wipe all the areas where the window contacts the frame with a good quality silicone lubricant. A little goes a long way with silicone lubricant, you don't need to saturate things with a direct blast. I would avoid wd-40, or other cheap oil sprays, it could make things worse.
As a QA Engineer for a local window and door company, researching some topics I stumbled across this post. Please check the humidity levels in the home (hopefully not too high). Make sure there is adequate air flow (open vents & curtains) in the room. And most of all, check the perimeter of the slider sash (operating/sliding portion) for a tight enough seal. This may include checking weatherstripping and critical measurements of the frame channel/pocket to slider/sash profile thickness.
Regards, Sunny H
One workaround is to install a heating cable along the perimeter. When you need to open the window you heat it up so it unfreezes.