Patent ID: 6929681

Claim:
An HVAC system including: a) an air freshening composition comprising a thermoplastic, semi-permeable polymeric gel having a fragrance material incorporated therein, b) a filter member including an air permeable filter medium: c) the polymeric gel containing a polymeric gelling agent selected from the group consisting of hydrogenated styrene/isoprene copolymers; volatile silicones; polyacrylic acids and mixtures thereof and being formulated to adhere directly on a surface of the filter member, the gel having sufficient viscosity at temperatures in the range of about 40° F. to about 150° F. to prevent run off of the gel from the surface of the filter to which it is adhered and to enable effective release of scented, volatile components in the fragrance material to provide an air freshening scent to air passing through the filter by dispersing the scented, volatile components into the air over a predetermined period of time.