Can Air Purifiers Filter Out COVID-19? Here’s How to Prepare Your AC After the Pandemic

walter-e-bennett.jpg  HVAC expert specializing in HVAC design.

  WWS contributor


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Air filters and cleaners are designed to filter out pollutants and biological contaminants from the air circulating your home. Therefore, it’s safe to say, these filters can filter out tiny particles and viruses as well. However, not all filters are the same, and without proper control over secondary factors, you cannot predictably limit the spread of the virus in your home.

In this article, we’ll be looking at how effective air purifiers and filters are at preventing COVID-19 spread, and what precautions you must take to prepare your AC system after the Corona pandemic.


What Are Air Filters and Air Purifiers?


Heating, ventilation, and air conditioning (HVAC) air filters and air purifiers remove micro bacteria, and pollen from the air. Despite that, air filtration is not enough to filter out the viruses that cause COVID-19. However, they still serve as the first line of defense against indoor viral disease spread.

As Linsey Marr, a Virginia Tech engineer who studies the airborne spread of viruses says, “Cleaning the air is at least as important as cleaning surfaces, but you do it very differently.”

Air filters can work to clean the air to some degree — if used properly. There are several types of filters out there, each differing in size and filtering capabilities against droplets, particles, and microbiological organisms. Each type of filter is, therefore, effective in a different HVAC context.


Droplet Filtration – Preparing Your AC to Prevent Viral Spread


The spread of COVID-19 is primarily droplet-based. Therefore, most public health guidance promotes social distancing. As a result, adequate droplet filtration built into the ventilation of your AC system should limit the spread of the virus. However, this requires the use of high-efficiency filters. While these filters trap a lot more dust and smaller particles, they also need to change more frequently.

Additionally, you need experts to install these specialized filters in your HVAC system as any leaks will prevent them from being effective.

Finally, if your HVAC system is not strong enough, the use of a high-efficiency filter will greatly drop the amount of conditioned air supplied into your home. Therefore, although you will have better filtration, the other aspects of the HVAC system will suffer.


Precautions When Changing Filters After Corona Pandemic


When changing the filters of your HVAC system during or after the corona pandemic you need to remember that they have active biological contaminants on them. Regardless of whether they are disease-causing, be extra careful when replacing them with new filters and dispose of them properly.

Take precautionary steps before diving in to replace the filters. Precautions to take include:

  • Turn the system off completely before changing the filters
  • Wear gloves before touching the filters
  • Wear respiratory protection before starting the job
  • Dispose of the old filters in sealed bags

It’s easier to leave this to certified HVAC maintenance specialists to handle this job rather than taking it on your own.


Why Not Replicate the Air Filtration Systems Used in Hospitals?


The filters in your home’s HVAC system are not adequate to safeguard against droplets in the air containing the virus responsible for causing COVID-19.

In the case of hospitals and other medical care facilities, their HVAC systems are built with specially designed mechanical systems that allow for and can accommodate high levels of filtration.

Moreover, they rely heavily on continuous monitoring and maintenance from dedicated healthcare personnel to ensure that all areas of the facility receive filtered air.

Furthermore, the facility takes additional steps such as ultraviolet lamps, advanced humidity control systems, and better airflow management to ensure maximum filtration and air purity.

Overall, these aspects of a medical facility’s HVAC system are very difficult to replicate in a home environment, thereby reducing an air purifier or HVAC’s air filter’s capabilities of cleaning the air of viruses.


Is the Simple Addition of A UV Lamp Adequate for Better Air Filtration?


To incorporate a fully functional UV system into your HVAC system requires a lot more effort than just simply adding in an additional UV lamp. Normal filtration, humidity control, and regular airflow management are factors that affect the rate of spread of viruses in the air.

Additionally, the infrastructure of the underlying system is also vital in determining the effectiveness of a UV lamp in stopping viral infection spread.

Therefore, without careful consideration of all factors involved, simply adding in a UV lamp is not an adequate line of defense against viral infections, and will not bring any benefits.


Ionizers, Ozone Generators, and Plasma – Are these effective measures against COVID-19 spread?


Despite all efforts, all these technologies fall short when it comes to effectively reducing viral spread within a building.

While they have shown great promise in a controlled laboratory setting, other real factors including several secondary issues in the context of a real building have rendered these as a less than ideal solution.




Although air purifiers and air filters in air conditioners aren’t a fool-proof solution to the spread of the coronavirus, when installed properly, they help immensely in reducing the chances of infection.

Moreover, with the use of high-efficiency filters, the spread of the virus in your home can be further controlled at the cost of HVAC performance.

Finally, once the corona pandemic passes over, you need to take several precautions before changing out the filters and replacing them with new ones.

Walter E. Bennet is a Texas-based HVAC expert who specializes in HVAC design for homes and multi-storied buildings. Together with his brother, Kevin & friend, Sam Green, they founded an HVAC company that handles intricate HVAC design, air duct cleaning, ac unit installation and ac repair in homes, offices and commercial spaces in all over Texas.