Air purifiers eliminate odors through various methods of filtration, often activated carbon filtration. Different brands of air purifiers utilize different types of filtration to remove odors from the air.
Activated carbon filters are widely used to remove gases, odors and chemical toxins from the air. When the carbon is treated with oxygen, a number of tiny pores are created. This allows the carbon to absorb many of the unwanted airborne particles. These particles attach to the carbon through a series of chemical attractions. Over time, the carbon becomes full of these unwanted particles and needs to be replaced.
High Efficiency Particulate Air filters are designed to filter 99.97 percent of airborne particles, including dust, pollen and pet dander. In order to manage odors, HEPA filters are often combined with more elaborate filtration systems. For example, Austin Air manufactures air purifiers combing a HEPA filter with a unique carbon/zeolite filter. This effectively eliminates pollutants and odors.
Charged media filters are another effective odor removing option. These utilize electrostatic energy and synthetic fibers to collect extremely small particles. The main disadvantage to this type of filter is its inability to hold a charge. Over time, the filter is less able to maintain the same charge level and has to be replaced.