A heat capacitor for a capillary aerosol generator comprises a phase change material that changes phases at a temperature approximately equal to a temperature sufficient to volatilize liquid material in a capillary passage of the capillary aerosol generator. The phase change material stores heat, which can be used to generate aerosol either continuously or intermittently over a given time. The use of stored heat in the phase change material to generate aerosol over time enables operation of the capillary aerosol generator remote from a large energy source.