What is a Carbon Filter and What Does it do?

What is a Carbon Filter and What Does it do? Related Information:

A carbon filter in an air purifier will remove the larger particles from the air and eliminate any odors that are present. Although HEPA filters are the best for removing particles larger than 0.3 microns, they do not remove gases and odors. Activated carbon is quite effective for performing both of these tasks because it uses the process of adsorption to remove gases and vapors from steam in the air. Adsorption is defined as the physical attraction and adherence of gas and liquid molecules to the surface of a solid. Activated carbon filters adsorb these molecules.

Activated carbon is a material that has been carefully tested and activated to increase the internal surface of the filter to the range of 950 to 1150 square meters per gram. The gases and vapors are held on the internal surface and is where the filter does its work. When the gas molecules come in contact with the surface of activated carbon particles, they rest on a large surface pore of the particles. The unbalanced forces outside and inside of the carbon particles cause the gas molecules to move down into the smaller particles of the carbon where it is trapped and held. They are then condensed into liquid particles.

The carbon filter will adsorb almost any type of gases and molecules. These include:

• Organic compounds such as acids, alcohols and aldehydes
• Chlorinated hydrocarbons such as esters, ethers, and ketones
• Inorganic compounds such as halogens and sulphuric acids
• Odors from humans, pets, cooking and many others.

There are many benefits of using a carbon filter in an air purifier:

1. It has the ability to adsorb some of almost any vapor.
2. It has a large capacity for organic molecules, especially solvents.
3. It adsorbs and retains a wide variety of chemicals at the same time.
4. It works well under a wide range of temperatures and humidity levels.
5. It is inert and safe to handle and use.
6. It is readily available and affordable.

There are many types of carbon filters that you can use in your air purifier. These range from coal based to coconut shell. Carbon filters are intended to physically absorb all the gas molecules into their pores. They, even activated carbon filters, are not very effective at removing the molecules for very humid air nor at removing lower molecular gases such as formaldehyde and nitrogen dioxide. For these problems, you need to have air purifiers that have Chemisorbers to chemically remove the gases. They react with the water molecules in the air and break them down into a harmless form, such as carbon dioxide.

The particulate filters included with the gas filters are very important. If the pre-filter does not work properly, then most of the micro-pores in the carbon will have to be used to filter out the particles not picked up by the pre filter. Therefore the gas filter could get saturated a lot faster with many pounds of activated carbon. A gas flow with fine activated carbon will also restrict the air flow, but if it has larger pellets the air will flow much easier. A pleated design in the filter will make the carbon surface area larger and thus increases the efficiency rate of the filter. The gas molecules will have a better chance of being absorbed by this larger surface.

Checking to see which type of filter the air purifier contains is essential when you are looking at all the available models to purchase for your home.