Is Your Activated Carbon Filter A Cheap Trick? How To Know If An Activated Carbon Filter Won't Clean Your Air How do you feel when someone sells you a product and afterward you discover it doesn’t do what was promised? Would you return again and again to the same vendor? This is precisely what you will do as you continue to buy filters for air purifiers that don’t clean the air. Is my contention true, those manufacturers who claim an activated carbon filter pad removes chemicals and odors are deceiving you? Please allow me the opportunity to present my case and you be the judge. Many air purifiers include activated carbon for gas and odor removal, but will not mention how much is in their filter. This is because, at best, they have coated a mat with a few token ounces of activated carbon. In an average home, that small amount of carbon could get saturated in days, even hours. After this, the filter would need to be replaced or it would be doing nothing. If an air purifier does not make any obvious claims about the amount of activated carbon it uses, you should question the filter's effectiveness. Why activated carbon filter pads don't give you the clean air you expect Air purification is big business and many companies have entered the air purifier market. However, these companies are not air purifier manufacturers solely in the business of air purification. They are consumer product sales organizations. Most manufacture nothing at all, but contract design and production to others. Their primary concern is to market whatever is the hot seller of the day. Eager to gain the approval of consumers they hype the fact that they offer "multistage" air cleaners that can control all sorts of air pollution. An activated carbon filter is usually featured as one of the stages in these air purifiers. They typically take the form of a foam mesh impregnated with a few token ounces of activated carbon. Is this good enough? Are these companies being honest? What about those manufacturers that offer a deep activated carbon bed that includes many pounds of activated carbon? Question the quality of the activated carbon Activated carbon can vary greatly depending on the methods used to produce it. For instance, the surface area available to adsorb pollutants can vary between 400 sq. meters per gram to over 1500 sq. meters per gram. Activated carbon can generally remove some of any chemical. However, raw activated carbon may not be very effective against many of the pollutants you're concerned about. That's why activated carbon needs to be impregnated with special catalysts and chemisorbers to ensure maximum effectiveness against typical pollutants. Air purifiers using an activated carbon filter pad never address these issues in any of their consumer literature. How can you know the real capabilities of their filter? You can't. Question the quantity of filtration How much chemical contamination can a few ounces of activated carbon adsorb? Activated carbon can adsorb as much as 60% of its weight in pollutants. This is best accomplished by increasing the "dwell time" or time spent in contact with the pollutants. An activated carbon filter pad cannot supply much in the way of dwell time. Air passes through such thin filters quickly. Filter pads with only a few onces of activated carbon have precious little time or capacity to make any real difference in your air quality. This is why high quality air purifier manufacturers whose business is nothing but air purification include a deep activated carbon bed that often weighs many pounds. Question the design of the air purifier All too often, activated carbon filter pads are used as a prefilter for a higher efficiency particle filter. This exposes the activated carbon to the incoming stream of dust and microparticles. The structure of activated carbon is that of macropores branching into ever-smaller micropores. Incoming particles can easily clog these larger pores and prevent gaseous contaminants from entering the micropores where adsorption takes place. Using an activated carbon filter pad as a prefilter is a bad design decision. Another bad decision that seems to defy all common sense is the inclusion of scent cartridges in air purifiers with activated carbon. Since activated carbon is supposed to remove odors and volatile chemicals from the air, why is a source of volatile chemical fragrance included? This seems to defeat the purpose of the activated carbon. The reality is that the scent masks the odors in the air and is intended to lead you to believe the air purifier is doing a good job. Activated carbon filtration works if you choose the right air purifier Activated carbon in air purifiers has real value when employed in a deep bed. There are several air purifier manufacturers that design and build there own products with this in mind. Some examples are Allerair, Austin Air, Blueair, and Iqair. These companies understand that a large volume of activated carbon is essential for air purifier performance. Activated carbon filter pads are a gimmick of marketing companies. These sales organizations are only interested in grabbing a piece of the air purifier market with inferior products. They rely on the absence of consumer education about air purification to succeed. You can make a much better choice. Return to Home Air Purifier Guide home page. If You Found My Site Useful You May Like These Featured Sites How does activated carbon work? Check out this Wikipedia article Short article with good links about activated carbon Custom Search