Typically a sliding sash window has gaps of around 3mm between the frame and sashes. In an average sized window these gaps are equivalent to a hole around 150mm in diameter. This allows:

• Air in the room to change up to three times per hour, resulting in inefficient use of energy.
• Difficulty in maintaining comfortable room temperature.

The Classic Window Co Perimeter Sealing System eliminates gaps so the air changes are reduced to less than once per hour, allowing the room temperature to be controlled to a comfortable level.