1” filters, or passive filters, capture particles on a material barrier to protect equipment from debris buildup. These filters are designed to protect your air conditioning and heating equipment rather than filter mold, bacteria, or other allergens out of the air. Filters that are too dense will cause an overheating HVAC system which leads to continually triggering the safety trip, thus dramatically reducing the overall lifespan of your HVAC equipment. In order to prevent airflow restrictions, these disposable filters should be replaced every month with inexpensive blue filters. Pleated filters restrict more airflow than intended for the HVAC, and may require heater repair sooner rather than later.