How are HEPA filters made?
The filter paper is bonded airtight inside a filter casing made from steel. HEPA filters are delicate, they cannot be vacuumed or cleaned but due to the considerable surface area of the filter paper they will generally last 3 years or more when used with proper pre-filtration. HEPA filters must also have an airtight seal or gasket on the external face to prevent air from bypassing around the filter. Air bypass is a common problem with air purifiers, where due to lack of a proper seal or filters are made from less than ideal sealing materials such as cardboard, paper or plastic, air bypasses around the filter resulting in efficiency being a fraction of the stated 99.97%. All InovaAir HEPA air purifiers are factory certified to filter 99.97% @ 0.3 microns efficiency. NB: Most residential HEPA air purifiers sold in Australia do not conform to medical grade HEPA standards. There is no regulatory authority which monitors claims by manufacturers that HEPA filters sold in either vacuum cleane
