Using this filter set is easy. First, make sure your Volta Sierra U4020 appliance is turned off. Then, carefully remove the old filters and replace them with the new ones from this set, following the correct installation positions. When it comes to maintenance, it's a good idea to check the filters regularly. If they look dirty, you can gently clean the foam filter with mild soap and water and let it dry completely before reinstalling. However, the hepa and exhaust filters usually need to be replaced when they're dirty or after a certain period of use, as recommended by the manufacturer. Remember, always keep your hands dry when handling the filters to avoid damage. With proper use and maintenance, this filter set will keep your appliance running smoothly for a long time.