When used correctly, air and HVAC filters can help reduce airborne contaminants, including viruses, in a small building or space. However, cleaning or filtering the air alone is not enough to protect people from COVID-19.Yes, most public health guidelines suggest that transmission of COVID-19 is predominantly associated with large droplets. This is why air filtration is only a small part of a solution, since it generally does not address transmission by contact with the surface or by close contact between people. The distinction between droplets and airborne droplets is particle size.
We know that droplets can remain in the air for long periods of time. For example, DNA and RNA from other viruses that are usually associated with droplets have been found in used filters. Therefore, what precautions should be taken when changing filters? Air filters that remove small particles, such as high-efficiency particulate air (HEPA) filters, are effective in removing contaminants from the air. Cabin air systems are designed to operate more efficiently by delivering approximately 50 percent outdoor air and 50 percent filtered recirculated air.
One of the ways you can improve the air quality in your home is to improve the filter in your HVAC unit. Ductless HVAC units that recirculate air, such as fan coils or split units, should be evaluated, maintained and cleaned according to manufacturer recommendations. Researchers suspect that the air conditioner spreads air particles containing the virus among three families and suggested that restaurants improve air filtration and separate their seats. The EPA also recommends running the system fan at longer intervals or continuously, because HVAC systems filter air only when the fan is running.If it's not possible to create a cross breeze, you can place a fan in front of an open window to increase airflow and blow indoor air out.
In fact, research shows that changing the air in a room several times an hour with clean or filtered outdoor air (using a window fan, using higher MERV filters in a heating, ventilation and air conditioning (HVAC) system, using portable air cleaning devices, and even simply opening a window) may reduce the risk of transmission of COVID-19.Studies show that five air changes per hour reduce the risk of transmission by 50 percent. Most aircraft have cabin air filtration systems equipped with HEPA filters that can eliminate viruses and germs quickly, reducing the risk of exposure to any possible infectious virus or bacteria expelled by coughing or sneezing.You can purchase approved air purification systems that are specifically designed to remove dust, mold, bacteria, and viruses from the air. The most common appliances that use HEPA filters are portable air purifiers, vacuum cleaners, and heating, ventilation, and air conditioning systems such as your oven. Before making any changes to the air filter of an HVAC system, users should consult their HVAC manual or an HVAC professional.One of the ways many people are trying to protect themselves from COVID-19 is by upgrading their HVAC filters and purchasing air filtration systems.
Use protection when changing the filter as particles inside the filter may contain live viruses. Because the filter only works when the system moves air through the filter and because particles are trapped they are not removed; therefore, the virus can continue to live inside the filter.