A New Generation of High-efficiency HVAC Filters that Can Be Used with Existing Infrastructure to stop the spread of coronavirus through recirculation of air

NWI has developed a multi-pronged approach to help increase the available capacity of filters that can be used as MERV 13 or higher but with a lower pressure drop. The target is a pressure drop of 65 Pascals or lower for a 24x24x2 inch filter tested at a flow rate of 1968 CFM.

Goal 1: Enhance NWI’s fibrillated spunbond technology previously used for facemasks by altering its structure and controlling consolidation to lower its pressure drop to 65 Pascals at a flow rate of 1968 CFM.  The spunbond process offers a significantly higher throughput. NWI’s pilot facility can produce as much as 200,000 meters per week.

Goal 2: Create staple carded nonwovens by using similar fibers as produced on the spunbond line. The structure will be consolidated by thermal bonding and/or needle punching to allow a much lower pressure drop. Two structures will be formed. The first will be a pleatable structure with a weight of 50 to 75 g/m². Another will be one inch thick and can be die-cut and inserted in the filter housing without the need for pleating. The weight will be ~300 to 350 g/m². This filter will be a depth filter and can offer better filtration compared to its pleated counterpart. 

Goal 3: Determine best microscale (fiber-level) and macroscale (pleat-level) geometries for the nonwovens generated under goals 1 and 2.