It uses hot air that is either free from water vapor or has very little of it, where this moisture plays a minimal or no role in the process of sterilization.
Eventually, the entire item reaches the proper temperature needed to achieve sterilization.
The presence of moisture, such as in steam sterilization, significantly speeds up heat penetration.
The flow created by the blower ensures uniform temperatures and the equal transfer of heat throughout the load.
An even more efficient system than convection uses deturbulized hot air forced through a jet curtain at 3000ft/minute.