The sudden and unexpected emergence of COVID-19 has everyone concerned about their family’s health and safety. Air filtration, understandably, has become a point of focus as people look for ways to limit their exposure to the coronavirus.
Whether air filtration can actually help protect you from the virus depends on a number of factors.
Let’s take a look at how filters work and what they’re capable of.
Understanding Filtration And Air Purification
Your HVAC system recirculates the air in your home several times a day. With each pass through the system, the air is filtered through a cartridge that removes pollutants.
The filter in your central air system has a MERV rating. That’s the minimum efficiency reporting value. The MERV rates the filter’s performance by the sizes of particles it can capture. The MERV ranges from 1 to 16. The smaller the particle, the higher the MERV.
MERV 1-4: These filters are cheap and disposable. They tend to be comprised of spun fiberglass. They can capture dust, pollen, and fibers.
MERV 5-8: These are also disposable, but they’re capable of filtering mold spores and chemical fumes.
MERV 9-12: This is typically a rigid style cartridge filter for superior residential air purification. It can filter out certain bacteria, such as Legionella, as well as common fumes.
MERV 13-16: This is also a rigid cartridge filter, but at 6 inches deep, it’s not commonly used in residential HVAC systems. You’re more likely to find this type of filter in hospitals and laboratories — sterile environments that need advanced purification. This type of filter removes all bacteria, sneeze droplets, and tobacco smoke.
There are also supplemental air purification systems, such as a plug-in HEPA filter and UV disinfection systems that work in conjunction with your HVAC. These can also help capture and neutralize airborne contaminants, bacteria, and certain viruses.
Filtration And Covid-19
The COVID-19 virus attaches to droplets released when a person coughs or sneezes. These atomized particles range in size from 1-100 microns, so any filter with a rating of MERV 9 or better would be effective in trapping them.
However, the coronavirus won’t stay in the air long. In order to be filtered out, someone would have to talk or sneeze right next to a vent. That isn’t to say advanced air filtration wouldn’t help. Remember, the coronavirus is expelled when someone sneezes or coughs. A high-efficiency filter will trap at least 85 percent of the contaminants that aggravate allergies and cause sneezing. This includes pollen, mold spores, fungi, and dust. Since sneezing creates gas clouds that can travel up to 25 feet, eliminating indoor irritants can potentially reduce the spread of active viruses.
The addition of a UV disinfection system will also neutralize airborne bacteria and viruses before they reach the supply vents.
The Importance Of Healthy Indoor Air Quality
Under any circumstances, clean air is essential to keeping your family healthy and safe. As part of a comprehensive indoor air quality strategy, filtration provides an added level of protection against many of the harmful contaminants floating around in the air.