Condensation can be a serious problem. Moisture produced by everyday activities shows up first on cool dense surfaces such as windows and can cause a number of different health and structural problems. The advanced Thermal Edge technology in North-Air windows keeps the glass much warmer so they are less likely to fog.
Some common sources of moisture:
- Cooking
- Washing dishes
- Showering
- House plants
- Stored wood
Click here (link to PDF) for more information on condensation. 
