Abstract: A disinfectant distribution system for heating and cooling ducts for purifying the air handled by a central forced-air heating or cooling system. The disinfectant distribution system for heating and cooling ducts includes a housing structure assembly including a housing having a front wall, a back wall, side walls, and a top wall, and being adapted to be securely attached to a heating and cooling duct; and also includes a conduit assembly being attached to and extended in the housing for transporting disinfectant spray from an aerosol can to the heating and cooling duct; and further includes a spray dispensing assembly being disposed in the housing and being adapted to dispense disinfectant spray from the aerosol can.