Final answer:
Filtration is the process of removing particles and contaminants from air in an air distribution system. HEPA filters are commonly used for this purpose.
Step-by-step explanation:
The process of removing particles and contaminants from air that circulates through an air distribution system is called Filtration. Filtration is a method used to physically remove solid particles and pollutants from the air by passing it through layers of materials such as sand, gravel, and charcoal. Filters like HEPA filters are commonly used in air conditioning systems to remove microbes, endospores, and viruses as air flows through them.