Mechanical filters are the quintessential air cleaners. They are physical filters installed in a central air/furnace system. When the system pushes air through the filters, they catch particulates and trap them, thereby removing them from the air.
When selecting a filter for your air filtration system, keep the following two factors in mind:
1. Filter rating – Minimum Efficiency Reporting Values (MERV) is the standard US system used to rate the efficiency of air filters to “capture larger particles between 0.3 and 10 microns (µm)” in size. A MERV 13 is generally recommended for homes with air handlers, central AC, and furnaces. High Efficiency Particulate Air (HEPA) filters are pleated physical filters that are rated to theoretically remove up to 99.97% of airborne particles that are 0.3 microns; they are not typically recommended for most home HVAC systems since many such systems cannot produce the airflow required to make use of these filters.
2. Filter material – Fiberglass, pleated, and activated carbon filters are all commonly seen in many air filtration systems throughout the St. Louis area. Fiberglass filters are preferred by homeowners on tight budgets, while activated carbon filters are praised for their efficacy at targeting VOCs. Pleated filters, however, are typically rated higher than other filter types and better at removing allergens from the air, making them ideal for households with asthmatic individuals and/or pets.