What is required for forced convection to occur in appliances?

For forced convection to occur in appliances, mechanical means, such as an electric blower, are essential. This process involves the movement of air or fluid by an external force, which enhances the heat transfer capabilities of the system. The use of a blower or fan helps to circulate the air around the heating elements and throughout the appliance, ensuring that warm air is distributed more uniformly and efficiently.

In contrast, natural airflow relies on temperature differences and does not involve mechanical force, making it less efficient in certain applications. High thermal resistance in materials may affect the heat transfer but does not facilitate forced convection. Gravity can assist in the natural flow of heated air, but it does not contribute to forced convection, which is specifically distinguished by the use of mechanical devices to initiate and maintain airflow.