Abstract: A heat exchanger includes a housing, a reservoir comprising a solid material mounted within the housing, temperature control means for controlling the temperature of the reservoir, and energy exchange means for allowing thermal contact between the reservoir and a substance for effectuating transfer of energy from the reservoir to the substance for regulating the temperature of the substance.

Abstract: An apparatus for producing aerosol from a substance includes a heat exchanger for receiving and cooling a substance. The heat exchanger includes a housing; a cryogenic reservoir comprising a solid material mounted within the housing; temperature control means for controllably cooling the reservoir; and energy exchange means for allowing thermal contact between the reservoir and the substance for effectuating transfer of cooling energy from the cryogenic reservoir to the substance for controllably cooling the substance. A delivery line has an inlet for receiving the substance from the heat exchanger at a first pressure. A nozzle is connected to the delivery line for receiving the substance from the delivery line. The nozzle has at least one exit opening which allows passing of the substance therethrough for expanding the substance from the first pressure to a second pressure which is lower than the first pressure for solidifying the substance and producing aerosol.