home ventilation helps Reduce viral spread

The evidence is overwhelming--a whole house fan can help reduce viral spread and is possibly the best investment you could make this spring

5 April, 2020

The EPA estimates that Americans spend an average of 90% of their time indoors, and due to the spread of Coronavirus, we are all spending even more time at home today.  While we all want to stay healthy, being cooped up with stagnant air could put many of us in a worse position.  Increased ventilation has been proven to reduce illness and the spread of bacteria and viruses in homes, schools, and workplaces, a fact that is even more valuable today.

What the research shows

The world’s leading health organizations have for years flagged poor indoor air quality as a culprit for the spread of infectious diseases, and it’s at the forefront now due to Coronavirus.

  • The Environmental Protection Agency (EPA) reports that indoor air can be 2-5 times more polluted than outdoor air, even in major metropolitan, smoggy cities and ranks indoor air pollution among the top four environmental hazards in America. 

  • The Centers for Disease Control and Protection (CDC) recently published guidance that after washing your hands and disinfecting surfaces, increasing home ventilation is the top thing you can do to prevent viral spread in your home, school, and workplace.

  • The American Lung Association says effective ventilation may also help keep bacteria, viruses and other pollutants out of the indoor air. 

  • The World Health Organization (WHO) has estimated that improved natural ventilation reduces lung-related illnesses by up to 20%.

  • A study by the National Institute of Health claims that most building air quality code is simply designed to ensure 80% of inhabitants won’t complain of foul smells, rather than addressing true air quality.


What most people don’t know

Many often ask, “Why not just rely on air conditioning to circulate the air?”  Because that’s what it does, it circulates the indoor air, rather than swapping it out for fresh air.  The WHO further explains regarding ventilation and airborne diseases that…

          "Well-designed natural ventilation systems can often be more effective than air conditioning in promoting effective infection control by increasing the number of air exchanges."

Sealed, circulation-focused AC systems don’t provide this benefit, unfortunately.  The Air Conditioning Contractors Association recently published:


          "Scientist[s] believe the principal transmission mode of the Coronavirus is by respiratory droplets, which may travel several feet from someone who is coughing or sneezing. Covering your mouth when you cough or sneeze is the first step to control the spread. However, residual contaminants can travel through your HVAC system, where all air in the home is circulated and can contribute to the spread of an airborne virus. The Coronavirus has the same traits as other viruses such as the common cold, the flu, and a sore throat by how it is spread from person-to-person. 

The HVAC system and duct system can contribute to spreading unwanted pathogens in the air, not because your system came contaminated from the factory, but because the air in your home became contaminated…Your HVAC system can provide biological growth the perfect opportunity to form and grow."

While the ACCA endeavors to educate its members of these challenges with traditional AC systems, the drawbacks of AC remain.  While opening a window is a good start, a passive approach like this may not be enough.  Those in isolation recovering from infectious diseases need fresh air exchanged into their rooms at least 12 times per hour to permit the rapid dilution of contaminated air into the surrounding areas and the open air according to the WHO.  This ensures pathogens are diluted and expelled rather than circulating or settling on surfaces.  An adequate whole house fan and ventilation system will exchange the entire volume of a home or building at least every 4 minutes—that’s 15x per hour. 

What to do…

Perhaps it’s time to install a whole house fan and improve ventilation in your home.  The American Lung Association would agree, as its website states:


          "Effective ventilation may also help keep bacteria, viruses and other pollutants out of the indoor air. Research shows that airflow and ventilation can affect how diseases spread indoors. The more stagnant the air is, the more likely diseases are to spread.  Ventilation can also limit moisture. Damp indoor spaces foster the growth and transmission of viruses and bacteria. Controlling moisture indoors can limit the spread of these infectious diseases and also limit mold, dust mite and cockroach growth."

And hopefully everyone is stepping up their game and disinfecting their homes and workplaces more often.  For that, the CDC states in its guide to disinfection that when handling strong cleaning substances:

          "...you should [be] wearing gloves and making sure you have good ventilation during use of the product."

It’s hard to measure the health benefits of improved home ventilation on a particular home, but the evidence is overwhelming.  Colorado Home Cooling does not make any claims that our products will prevent illness or cure disease, but the world’s leading health organizations have spoken on our behalf.

Feel free to read more about why CHC is most suited to help you address your home's needs.



CHC does not make any guarantees or claims related to home health improvements by its products but rather cites factual claims by government organizations.