HEPA filters are the ultimate standard for air filtration, and are often installed in hospitals, trapping 99.97% of particles as small as 0.3 microns at the baseline. These filters can remove microscopic substances from the air, such as mold, dust and pet dander. HEPA filters are the standard filtration system in medical environments, such as hospitals and clinics, mainly because they have the ability to remove not only inorganic dust suspended in the air, but also microscopic organisms that can cause serious damage. Examples include airborne viruses, bacteria, dust mites, mold spores, and pollen. HEPA uses thick, pleated media instead of flat fiberglass media used in standard filter types.
This is to significantly expand the surface area for filtration, as well as the life of the filters. Better filtration also helps keep the interior free of harmful particles all year round. Air and HVAC filters are designed to filter contaminants or pollutants from the air passing through them. Cleaning and filtering the air can help reduce pollutants in the air, including particles that contain viruses. The key questions to ask when deciding on a filter are the size of the filter you need and what you want to filter.
What the fine print will tell you is that HEPA filters can trap up to about 99.97 percent of the tiny particles, contaminants and allergens found in most indoor air environments, up to a size of about 0.3 microns. With a high MERV rating of 13, this 1-inch electrostatic pleated filter can attract and capture microscopic particles. When used correctly, air and HVAC filters can help reduce airborne contaminants, including viruses, in a small building or space. Alternatively, HEPA filtration options for residential spaces include external HEPA filters or whole-house air filters, types of filters that connect to the duct network via a small bypass circuit. And activated carbon filters can eliminate many strong scents, including kitchen odors or tobacco smoke. Keep in mind that UV filters should be used in conjunction with an air filter that takes care of the particles themselves. HVAC systems are known to perform a number of different functions, including removing hot and stale air and replacing it with fresh air in a process called ventilation, as well as removing undesirable air pollutants such as dust mites, tobacco smoke, airborne bacteria, pet dander, pollen and carbon dioxide. A HEPA filtration system provides the highest efficiency with an efficiency of 99.97% for contaminants as small as 0.3 microns.
An effective HVAC system has nine common components that you should be familiar with, including the air cleaner, air return, blower, coils, compressor, condenser, ducts, electrical elements and exhaust outlets. While no HEPA filter will remove all contaminants from indoor air, a high-efficiency filter combined with a well-maintained HVAC system can go a long way. There have been questions about whether DIY air filters can be effective in reducing virus particles indoors; however it is important to note that only an air filter with a MERV rating of 13 or higher (or one that is specifically designated a HEPA unit or indicates that it filters particles in the 0.1-1 µm size range) will be able to capture these particles. It is also important to note that HEPA filters have more resistance to airflow than MERV filters due to their high rate of particulate capture; therefore it is important to ensure that your HVAC system is regularly maintained so that dusty air filters do not reduce their efficiency or cause contaminants to accumulate in ducts.