Activated carbon has special properties that make it an ideal choice for removing volatile organic compounds (VOCs), odors, and other gaseous pollutants from the air. It works differently than other air purifiers, such as HEPA, which only filter particulate pollution. Charcoal filters also help to eliminate unpleasant odors, so indoor air stays fresh. When used together, activated carbon and HEPA filters can trap 99.97% of small particles of 0.3 microns or larger, as well as most larger particles, especially spores. Activated carbon filters can be especially beneficial for people who suffer from allergies or are aggravated by impure air, including those exposed to second-hand smoke.
If you smoke or live with someone who does, using an activated carbon filter in your home air purification system can provide unparalleled benefits to your respiratory health. Carbon filters can also effectively remove or reduce many contaminants from water, including VOCs, chlorine, lead, fluorine, pesticides and more. For a more complete list of what carbon filters can eliminate, read What do Carbon Filters Eliminate?It's important to keep in mind that activated carbon alone does not remove all contaminants. Certain minerals, salts and metals can slip through the filter.
However, this is only true for GAC filters. Carbon block filters are capable of removing many more contaminants, including metals such as lead. Carbon block filters also remove microbiological contaminants from drinking water, including waterborne pathogens. The best carbon block filters reduce pollutants such as arsenic, asbestos, mercury and radon. As a general rule, activated carbon is purer and of better quality than charcoal.
Activated carbon can be useful as a filter and it is certainly highly preferable not to filter water at all. The amount of pollution activated carbon removes from air or water depends on many different factors, including the type and amount of pollution, the acidity and temperature of the water or air, and the length of time the water or air remains in contact with the activated carbon. Water flows more freely through GAC filters than through carbon block filters. This means that GAC filters have higher flow rates than carbon block filters. German researchers at Stiftung Warentest* have tested air purifiers with filters (Philips, Dyson, Soehnle, Rowenta), with the result that activated carbons capture very little formaldehyde. Some filters that are simply labeled “carbon” are made with blocks of carbon dust that are compressed and heated to create the filter.
This type of carbon filter can be used as a pre-filter and “polish” or final filter in the water filtration process. However, for many homes, a carbon block filter provides more than enough filtered drinking water every day. It's best to use a direct manufacturer such as Filterbuy that allows customers to order custom-sized air filters online. GAC filters are generally used as polishing filters in the water filtration process and are very effective in improving the taste and odor of drinking water. All activated carbon filters remove significantly more pollutants from the air than normal carbon filters; however there are some distinctions between them. The main difference between a water filter that uses activated carbon and one that uses charcoal is in the filter materials themselves. Based on their observations on isopropanol filtration (another VOC present in gasoline and hydroalcoholic gel), CAF filters would be 26.8% less efficient than GAC filters. When selecting an air filter for your home or office it's important to consider all factors in order to confidently select the best one for your needs.
Activated carbon is an excellent choice for removing VOCs and other gaseous pollutants from both air and water.