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Can COVID Spread Through HVAC Systems?

With the world still battling the COVID-19 pandemic in its evolving forms, safety procedures to reduce the spread are still as important as ever. Global research communities are continuously looking for new ways to reduce the spread of this virus by developing realistic solutions.

One major public health hurdle is controlling indoor air quality. A lot of debate and scientific studies are being carried out on the role of HVAC (or heating, ventilation, and air conditioning) systems in the transmission of the COVID-19 virus.

HVAC systems offer comfortable environment conditions such as relative humidity and temperature, and they clean the air in indoor settings. These systems provide clean air circulation through indoor and outdoor air exchange and filtering. Because of how they circulate air, their role in COVID-19 transmission risk is still being investigated.

Can COVID spread through HVAC systems, and what can you do to keep your home or business safe from the virus?

Does COVID Spread Through HVAC Systems?
Poor air ventilation rates, especially in confined indoor spaces, are linked to increased transmission of respiratory tract infections like rhinovirus, tuberculosis, influenza, and tuberculosis infections. Equally, SARS-CoV-2 (the virus that causes COVID-19) transmission risk is possible, especially in enclosed spaces, including transmission from pre-symptomatic COVID-19 cases.

However, the CDC reports that, although airflow within a specific space can spread diseases among people within the space, there is currently no definitive evidence that viable SARS-CoV-2 can survive inside the system, requiring it to be replaced.

Understanding Coronavirus Particles and How They Travel
Coronavirus particles have a size of about 0.1 microns—1/700th the width of human hair. As a result, they are easily transmissible and challenging to regulate.

The spread of Coronavirus from one person to another occurs through:

Close contact or being within 2 meters of an infected person for 15 minutes or more, or through physical contact; for instance, hugging an infected person.
Respiratory droplets from the mouth and nose when you talk, cough, sneeze, laugh, sing, or breathe.
Aerosols, which are smaller and lighter respiratory droplets that may stay longer in the air. Infectious aerosols may also be created during some dental and medical procedures.
Touching surfaces with the virus on them and then touching your nose, eyes, or mouth before washing your hands.
The severity and rate of spread of the SARS-CoV-2 has pushed engineers to take further measures to boost indoor air quality. Most available reports show that transmission of the COVID-19 virus is possible even in instances where there is no physical contact with contaminants, infected fomites, or people.

Furthermore, over 239 scientists from 32 countries have written an open letter to the World Health Organization (WHO) to confirm the airborne transmission route of SARS-CoV-2. So, it’s strongly suggested that heating and cooling systems have a role in the spread of the COVID-19 virus.

How Heating and Cooling Systems Work
To put it simply, a central heating or cooling unit controls the temperature of your home or business by moving air, typically through a system of ductwork and air vents. In the summer, warm air and humidity is moved from inside your home to the outside, and in the winter, cool air is warmed by a furnace or heat pump. There’s also the “V” in HVAC to consider—ventilation. Ventilation refers to the replacement of stale, indoor air with fresh, outdoor air. Ventilation can occur naturally through small cracks, or mechanically using your HVAC system’s ducts and fans.

Can COVID-19 Travel Through Air Vents?
In the U.S., most homes use a forced-air heating and cooling system (also called central air). This type of HVAC system only recirculates indoor air, meaning that airborne illnesses like COVID-19 are also recirculated and travel through your home’s air vents over and over again.

That’s why it’s so important to have proper ventilation in your home or business—ventilation, as we discussed, replaces indoor air with clean outdoor air, diluting it and reducing the spread of airborne illnesses. Good ventilation also helps to improve the efficiency of your home’s heating and cooling systems, removes excess moisture, and keeps airborne allergens under control.

At 3H AC, we specialize in repairing and installing residential and commercial ventilation systems in the Tampa Bay area—contact us to learn how we can help improve your indoor air quality.

Of course, good ventilation is not a replacement for other COVID-19 risk reduction strategies, like social distancing, covering your mouth and nose with your elbow when you cough or sneeze, and washing your hands frequently.

New Technologies For Combating COVID-19 Spread Through HVAC
Effective ways of mitigating or eliminating the transmission of COVID-19 particles are essential as the world continues fighting this deadly pandemic.

According to The American Society of Heating, Refrigerating and Air-Conditioning Engineers, airborne transmission of coronavirus is significant and can be controlled through changing building operations—including operation of heating, ventilating, and air conditioning systems to lower airborne exposures.

When it comes to HVAC systems and the role they play in the airborne transmission risk of the virus, here are a few technologies that can help out:

Reconfiguration of Present HVAC System
An existing HVAC system can be reconfigured to have a higher air exchange rate to lower the number of viral particles in the indoor air. Reconfiguration is achieved by introducing fresher air into the HVAC system and preventing recirculation of air already contaminated with the virus.

Airflow speed can also be reduced by incorporating fixed-speed motors to regulate how far the contaminated air will travel. A HVAC professional can help you in upgrading your existing HVAC system to improve indoor air quality.

Using HEPA Air Filters
HEPA filters or High-Efficiency Particulate Air filters are also a great mitigation strategy in lowering the spread of COVID-19 in the indoor environment. These portable air cleaners will filter out all particulates that are above 0.3 microns. These air filtration systems will help to eliminate the larger infectious droplets from your space.

They also help enhance indoor air quality by lowering the number of overall viruses, bacteria, and allergens. Getting a filter system that has a MERV-13 rating or higher is great at trapping smaller particles, including viruses.

Using Ductless HVAC Systems
You can prevent the transmission of coronavirus particles by replacing a ducted HVAC unit with a ductless heat pump. Mini-split HVAC devices will still recirculate indoor air rather than bringing in fresh air from the outdoors into buildings. However, its mechanism of action is different from the ducted systems. Usually, the air exchange will stay within the room for indoor ductless units. As a result, you have no air shared throughout the indoor space where ducts will carry them between rooms.

Good Indoor Air Quality and Adequate Ventilation Can Help Reduce The Spread of COVID-19
SARS-CoV-2 viral particles tend to spread more readily between people who are indoors than outdoors. A multi-layered approach should be used to reduce the spread of the Coronavirus in indoor environments that use HVAC systems.

Homes and offices require improvements in building air ventilation systems and indoor air quality to lower the spread of disease-causing pathogens and reduce the risk of COVID-19 exposure. In addition, wearing face masks, physical distancing, vaccination, and hand hygiene should also be encouraged.

Protective interventions, disinfections, and ventilation practices will lower the airborne concentrations and shrink the overall viral dose that occupants are exposed to.

Contact or call 3H AC today to get more information on how we can assess and improve your indoor air quality.

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