What is the primary function of weatherstripping in a window installation?

The primary function of weatherstripping in a window installation is to prevent air and water infiltration. Weatherstripping creates a seal between the moving parts of a window, such as between the sash and the frame, which is crucial for maintaining a comfortable indoor environment. This seal minimizes drafts caused by air leaks, thereby enhancing energy efficiency and maintaining consistent indoor temperatures. Additionally, effective weatherstripping prevents water from entering the building envelope, which is essential for protecting the interior from moisture damage and maintaining structural integrity. Thus, the role of weatherstripping is fundamental in ensuring that windows perform well in terms of insulation and protection against the elements.