What is the role of pre-filters in an air filtration system?

Pre-filters play a crucial role in air filtration systems primarily by serving as the first line of defense against dust, dirt, and larger particles before they reach the main filter. By capturing these contaminants, pre-filters help to reduce the load and the amount of particulate matter that the main filter has to handle. This action extends the lifespan of the main filter, allowing it to function more efficiently for a longer period without the need for frequent replacements. This efficiency not only leads to cost savings in terms of filter replacements but also enhances the overall performance of the air filtration system.

While the goal of the entire filtration system is to improve air quality, the specific function of a pre-filter is not to directly enhance air quality itself; rather, it's to protect and optimize the performance of the main filter. The assertion that pre-filters capture all particles is incorrect, as they typically target larger particles, which means smaller particulate matter may still reach the main filter. Increasing noise levels is not a function of pre-filters; in fact, well-designed filtration systems aim for quiet operation. Thus, the primary purpose of pre-filters is indeed to prolong the life of the main filter, making option B the correct answer.