A method of sterilizing material includes receiving the material in a sterilizing chamber, vaporizing sterilant supplied to vaporizer from a sterilant source, exposing the material to the vaporized sterilant by conducting a sterilization cycle in the sterilizing chamber, heating ambient filtered air supplied to the vaporizer from an ambient filtered air source, and removing residuals of the vaporized sterilant absorbed or adsorbed by the material during the sterilization cycle by conducting an aeration cycle in the sterilizing chamber. The removing of the residuals includes conducting a plurality of aeration pulses to provide the sterilizing chamber with an aeration atmosphere comprising the heated filtered air to vaporize the absorbed or adsorbed residuals, and conducting a plurality of aeration vacuum pulses to evacuate the aeration atmosphere and vaporized residuals from the sterilizing chamber.