This section provides background information related to the present disclosure which is not necessarily prior art.
Modern window assemblies in residential, commercial and industrial buildings may include one or more window sashes that are movable within a window jamb. Window sashes that move vertically to open and close often include two or more window balance assemblies. The balance assemblies urge the window sash upward (i.e., toward an open position for a lower sash or toward a closed position for an upper sash) to assist a user in moving the window sash and to retain the window sash at a position selected by the user.
The window jambs are positioned on either side of the window sash and form jamb channels in the window frame along which the window balance carrier traverses as the window sash is opened and closed. Adequate clearance is provided in the jamb channels to permit the carriers to move freely up and down. As a result of the movement of the carriers, however, there is a “chimney effect” that permits air and airborne dust and debris to flow into and through the jamb channel. This potentially adversely impacts the free movement of the window sash in the jamb channel. For example, as dust or dirt particles enter the jamb channel, they can deposit on the walls of the jamb channel. An increase in friction between the carrier and the jamb, or some other interference or degradation in the free movement of the carrier, may result causing the force needed to move the window sash to increase.