Airflow for the home comes into your system at a constant rate to keep fresh air cycling throughout it. The old air cycles out and the fresh, new air cycle inside in order to prevent stagnation and dryness from affecting indoor air quality. However, the air coming in is not necessarily always going to be the cleanest. There may be any number of pathogens, contagions, dust, dirt, sand, mould, bacteria, dangerous as coronavirus, allergens or pollutants floating around your home. The air filters you have installed in your systems act as cleansers, keeping air coming through but preventing entry to harmful irritants.1 Air Filters and Their Purpose The home air filters in a system are able to capture passing air particles in a tight mesh weaving designed to also allow airflow to flow through naturally. Your home benefits from all the freshness the incoming air provides without having to deal with any of the harmful particles. The mesh weaving is rated on the Minimum Efficiency Reporting Value (MERV) scale. The higher the rating, the more effective the filter is and the tighter its mesh weaving. Your air filters are capable of continuing to catch particles until they become covered in them and grow less effective over time.