A hot-air oven is an electrical device that uses dry heat to sterilize items. It is mostly found in hospitals, where medical personnel use it for sterilizing surgical equipment.
A hot-air oven has a digital thermostat that regulates its temperature, which normally ranges from 50 to 300 degrees Celsius. It also has a double-wall design, with the outer layer being metallic and the inner layer being a poor heat conductor, so that it retains heat and reduces energy output. The space between the two walls is filled with air to provide additional insulation. Inside the hot-air oven, a fan distributes heat evenly.
Hot-air ovens must be preheated to ensure that the complete cycle of sterilization is effective. A complete sterilization cycle involves preheating the oven to the required temperature, ensuring that the temperature is maintained, turning off the machine and then allowing the items to cool to room temperature in the closed oven. It takes approximately 90 minutes for a conventional hot-air oven to complete its sterilization cycle. However, there are other ovens that use higher heat levels to shorten the sterilization cycle.
Advantages of hot-air ovens include: less pressure buildup compared to autoclaves, no water is required during the sterilization process, they are smaller than autoclaves, and they are very efficient.