Are air purifier manufacturers that claim an activated carbon filter pad can remove chemicals and odors deceiving you?
Many air purifiers use activated carbon for gas and odor removal, but will not mention how much is in their filter. This is because they have simply coated a mat with a few 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 to the amount of activated carbon it uses, you should question the filter’s effectiveness.
To learn more about activated carbon for air purification view these additional articles:
- Why is activated carbon filtration essential in your air purifier?
- Activated carbon air cleaner report | The purifiers that really perform
- Choosing activated carbon filters | How to evaluate air purifier quality
- Activated carbon for odor control in your home
Why an activated carbon filter pad doesn’t give you the air purification you expect
Air purification is big business. Realizing the demand for air purification, many companies have entered the air purifier market.
However, you should take note: These companies are not air purifier manufacturers whose sole business is 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 blanket the market with whatever is the hot seller of the day.
Eager to gain the approval of consumers by giving the appearance of quality and superiority, they hype the fact that they offer a “multistage” air cleaner that can control all sorts of air pollution.
Activated carbon filters are usually featured as one of the stages in these air purifiers. They typically take the form of a foam mesh impregnated with a few ounces of activated carbon.
Is this really good enough? Are these companies really 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
First of all, lets bring up the question of 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.
Also, it is true activated carbon can generally remove some of any chemical. However, raw activated carbon may not be very effective against some of the very pollutants you’re concerned about. That’s why activated carbon needs to be impregnated with special catalysts and chemisorbers to ensure maximum effectiveness against the pollutants you wish to target.
Air purifiers using an activated carbon filter pad never address these issues in any of their consumer literature.
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. This is why air purifier manufacturers whose real business is nothing but air purification include a deep activated carbon bed that often weighs many pounds.
Question the design of the air purifier
Activated carbon filter pads are often used as a prefilter in front of 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 filter pads. 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.
Purification with activated carbon works if you choose the right air purifier
Activated carbon filters have real value when they take the form of a deep activated carbon 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.