What is one active cooling solution for a PC?

Adding an additional case fan is an active cooling solution because it involves using a powered device to enhance the cooling capability of a computer system. Case fans improve air circulation by moving air in or out of the case, helping to dissipate heat generated by the internal components, such as the CPU and GPU. This active movement of air lowers temperatures more effectively than passive solutions, which simply rely on the natural convection of air.

In contrast, replacing thermal paste, improving airflow, and cleaning dust from components primarily address the efficiency of existing cooling methods rather than adding new active cooling elements. While these aspects are crucial for maintaining optimal performance and heat management, they do not constitute active cooling solutions as they do not directly increase the system's cooling capacity through the introduction of additional powered components.