AllerAir is proud to offer air purifiers that feature the deepest carbon beds on the market, with up to 40 different proprietary carbon blends. Our carbon beds are made up of actual granular pieces of carbon, not crushed carbon, and can be customized with between 4 pounds and 120 pounds of carbon to efficiently adsorb any gasses, odors and chemicals. The lifespan of our carbon is far greater than many competitors, and has an unparalleled adsorption capacity.AllerAir units have metal housing, not plastic ones, and are designed with powder-coated paint, preventing any off gassing. Their carbon filters are also lined with two additional pre-filters, providing increased filtration, and extending the performance of the Super HEPA filter. The carbon canisters are also refillable and thus environmentally friendly.With increased dangers and illnesses associated with poor air quality, AllerAir also recognizes the responsibility it has to create units that provide businesses and residences with the cleanest indoor air available. AllerAir is proud of its superior carbon filtration methods, and takes it a step further by offering more options and features at an equal or better price value than its competitors. With the most extensive line of air purifiers available on the market and North American manufacturing, AllerAir is confident that its line of products is the most advanced on the market.