What is the purpose of using pre-HEPA filters in a filtration system?

Using pre-HEPA filters in a filtration system primarily serves to remove gross contaminants from the air before it reaches the HEPA filter. This initial filtration step is crucial because HEPA filters are designed to capture very small particles, such as bacteria and allergens, but can quickly become clogged if larger particles are allowed to pass through. By trapping these larger particulates, pre-HEPA filters extend the life of the HEPA filter, improve overall system efficiency, and ensure that the environment remains as clean and sterile as possible, which is especially important in laboratory and animal care settings where air quality directly impacts health and research outcomes.

This process helps maintain optimal airflow through the system while providing a higher standard of cleanliness, as the pre-HEPA filters effectively mitigate larger disruptive elements from being present in the air, thus allowing for a well-functioning filtration system. The other options, such as enhancing airflow, cooling air, or humidifying air, do not directly pertain to the primary function of pre-HEPA filters, which is focused on contaminant removal.