The efficient operation of the vacuum cleaner and its power is provided by the filter element. HEPA stands for High Efficiency Particulate Air or High Efficiency Air Purification and is the perfect design for fine purification. Liver filter filters the smallest 0.03 micron dust particles. The most powerful varieties don't even pass 0.5% contamination. What a liver filter looks like: It's a small, porous "accordion" that sits where the air exits the vacuum cleaner. Bricks are disposable and reusable, just like a dust collector. Disposable paper is made of paper and fiberglass, and reusable is made of fluoroplastic filled with porous activated carbon. It is this substance that traps dust particles and absorbs odors. A reusable filter can be washed, but that doesn't mean it will last the life of the vacuum cleaner. As they work, the efficiency of HEPA filters decreases due to the accumulation of large amounts of particulates. The vacuum cleaner must be replaced with a new one in time to prevent the vacuum cleaner from becoming a source of infection. A filter can be used for 0.5 to 1.5, or even 2 years. Exact data is indicated by the part manufacturer, for example Samsung recommends 1-1.5 years of design. More frequent replacements are recommended because over six months or a year, dangerous microbes build up and multiply in the blocks, and when cleaned, these microbes can return to the air in the apartment.