Dust, pollen, dust mites, and other particles inhabit industries, businesses, homes, and automobiles. Filters placed within the heating and air conditioning systems prevent those particles from contaminating delicate equipment and causing allergic reactions in sensitive individuals. While HEPA filters have the highest filtration standards, other types of filters are adequate for use at work, home, and in the automobile. When searching for a replacement filter, buyers should look at the item's specifications to ensure that they purchase the right filter and avoid damaging the appliance.
A high-efficiency particulate air filter, or HEPA filter, traps 99.97 per cent of pollen, dust, and other particulates down to 0.3 microns. A HEPA filter consists of interwoven fibres that trap the particulates before they pass completely through the random fibre arrangement.
Uses of HEPA filters
Developed in the 1940s as part of the World War II U.S. nuclear weapons research, the Manhattan Project, HEPA filters prevented radioactive particles from spreading and contaminating the laboratory. Because of their ability to remove tiny particles from the air, or the airline, biomedical and pharmaceutical industries, as well as home heating and cooling systems, air cleaners, and vacuum cleaners, use HEPA filters.
How it works
A HEPA filter uses three methods to capture particles: interception, impaction, and diffusion. When the filter intercepts a particle, the airflow through the filter brings it close to a nearby fibre, where it sticks, while impaction directly catches larger particles when they hit the fibres. Diffusion works by slowing the tiniest particles, down to 0.1 micron, so the fibres have a greater chance of capturing them before they pass through to the other side of the filter.
Regular air filters
While held to a high standard under the Australian AS4260-997, HEPA filters are not the only filters on the market. Manufactured as general replacements or for specific products, filters vary in their ability to remove particles from the air. These other filters, rated under the minimum efficiency reporting value or MERV rating, vary in their ability to remove particles from 0.3 to 10 microns from the air. For home use, most filters are in the MERV 1 to 8 range, filtering out particles from 1.0 to greater than 10.0 microns.
Some air filters advertise as HEPA-like, meaning that they have high filtration rates, but not as high as the official HEPA standard does. Generally, these filters are in the MERV 9 to 16 range, trapping bacteria, dust, smoke, and other contaminants, as well as larger particles, such as carpet fibres, mould spores, pet dander, and pollen. Before purchasing a replacement filter, the buyer should always check the item's specifications. HEPA and high-end HEPA-like filters have a reduced airflow due to their tightly woven fibres and density, and this reduced airflow can severely damage products that require a high airflow. The motor cannot draw the air through the filter quickly enough to provide adequate circulation and cooling.
Carbon air filters
While HEPA filters are highly efficient at removing particles from the air, they do not remove gases or smells. A variety of filter manufacturers make carbon air filters that contain an activated carbon cartridge to remove the smells of cigarette smoke, pets, and flatulence from the home and automobile. Air filters are not interchangeable; buyers should ensure that they purchase the filter made specifically for their appliance or automobile.
Automobile cabin air filters
The cabin air filter, also known as the air conditioning filter, is not the same as the engine filter under the bonnet, which filters the air before it enters the engine. Located behind the glove box or inside the dash, the cabin air filter removes particles and odours from the interior of a car. Part of the vehicle's air circulation system, the manufacturer's recommended replacement filter may be made of pleated paper, paper and cotton fibre, or cotton fibre. Some cabin filters also incorporate activated carbon to help reduce odours. Most automobile manufacturers, depending on the model, recommend changing the cabin air filter once a year, or every 19,000 to 24,000 km.
How to buy air filters on eBay
When you need some clean air, take a foray into the vast array of listings on eBay. By using the search bar, you can find the replacement air filter for your furnace, air cleaner, or automobile. You can simply type in "filter" and the make and model of your item. After clicking on the search button, peruse the descriptions of filters until you find what you need. After you finalise your purchase, you do not have to wait long before you replace that dirty filter and your lungs breathe a sigh of relief.