Coronavirus & Indoor Air Quality: Myths & Truths

Over the course of the last forty-five days, hundreds of millions of people have sheltered in place as governments issue executive orders to help slow the spread of the coronavirus (COVID-19). As a result, many homes are becoming a fortress against the virus, a make-shift school, an office outpost and a daycare facility. Now, more than ever, homeowners are thinking about the wellbeing and efficiency of their homes.

The coronavirus has raised many questions about the air we breathe outside and inside our homes. Due to the ever-changing global pandemic, there is mixed, and straight up false, information out in the ether. Resideo spoke with IAQ experts to help set the record straight.

As background, the World Health Organization (WHO) reports that the coronavirus is spread via droplets, usually through sneezing and coughing, and can temporarily stay suspended in the air depending on heat and humidity levels, but also live on hard surfaces.

Myth 1: There are indoor air quality solutions that can kill the coronavirus.

The bottom line is that there are no IAQ products on the market that can protect you from contracting the respiratory virus.

It is a stretch to claim you can completely eliminate airborne viruses in your home because IAQ solutions only help treat the flow of the air that is in the ductwork, not those living on hard surfaces throughout the home or floating in the air. What remains true is that IAQ solutions, such as air-cleaning systems and ultraviolet (UV) lights within the ductwork, can help reduce the number of certain viruses in the duct system and consequently, cleaner air is released through the duct work into the homes. Through proper ventilation and filtration, the air in the home will have less contaminants and that can reduce likelihood of transmission.

Myth 2: An increase in relative humidity and the summer months will slow the spread of coronavirus.

While studies show that the risk of transmitting a general respiratory virus decreases in the spring and summer – there haven't been any studies on this strain of the coronavirus.

Recent studies from the Annual Review of Virology have been cited by the media and show that indoor humidity may slow respiratory viruses spread. Written by Yale researchers, the recent review explored how respiratory viruses are transmitted, and reported that as humidity increases during spring and summer, the risk of transmission of a virus through airborne particles decreases both outside and indoors. Experts also agree that as we open the country back up, and people begin leaving their homes, there will still be coronavirus this fall. The most effective way to mitigate the coronavirus transfer is still physical distancing, washing your hands frequently and disinfecting hard surfaces.

Myth 3: The air inside my home won't impact my health.

Now that many families are spending more than 90% of their day inside their home, many are finding that their home is poorly ventilated, which can impact both physical and mental performance.

Since the 1980’s, the WHO and the U.S. Environmental Protection Agency (EPA) have reported that decreased ventilation can lead to complaints of headaches, eye, nose, or throat irritation, skin issues, dizziness, nausea, and sensitivity to odors.

If you’re working from home and feeling drowsy, tired, or having difficulty concentrating, that could be a result of elevated carbon dioxide (CO2) levels – the air we breathe out. Researchers at SUNY and Syracuse reported that participants showed signs of drowsiness, fatigue and a lower ability to perform simple mental tasks when exposed to elevated CO2 levels. Resideo found that in 2019, 60% of homes had high CO2 levels.

Myth 4: Keeping my windows closed this spring is the key to better IAQ.

The change in season poses some unique challenges – such as seasonal allergens – but improving ventilation by adding fresh air or installing a proper air filter can reduce the concentrations of infectious agents in your home and are important to improved IAQ.

The Centers for Disease Control and Prevention suggested that having good air flow, such as an air conditioner or an open window (if weather permitted), would bring in fresh air and could dilute the infectious rate of the Middle East respiratory syndrome (MERS), which also is caused by coronaviruses but is not the same as COVID-19. Researchers have shown that increasing the air exchange in an indoor space by two to three times per hour resulted in a 72% reduction of tuberculosis transmission. The key to adding fresh air ventilation needs to also consider filtering the incoming air to reduce dust, smoke, ash, pollen and other outdoor contaminants from entering your home. Keep in mind, these weren't studies done on the novel coronavirus, but offer helpful context during this uncertain environment.

Myth 5: All air filters for my air conditioning or furnace system are basically the same.

NOT TRUE! Three factors can have a big impact on how to reduce contaminants circulating in your indoor air:

• The MERV rating. The Minimum Efficiency Reporting Values (MERV) ratings were set by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) to define a filter’s ability to capture airborne particles from the air passing through between 0.3 (pollen) and 10 (dust, dander, mold) microns (µm). However, viruses are even smaller. Other coronaviruses are 0.1 to 0.2, so this also is what the size of COVID-19 is expected to be. This means you want to select a high MERV-rated filter to help lower the concentration of airborne virus particles. A MERV 11 filter can capture 32% of 0.3 µm, whereas MERV 13 can capture 63% and MERV 16, 95%. As context, the N-95 facial masks that health-care workers wear are rated to capture 95% of those particles 0.3 µm in size. All these filters will be less efficient with smaller particles, but they can reduce airborne particles.
• The Thickness. A four-inch filter will help stop more small particles than a standard one-inch filter because the thickness offers a larger barrier to entrap particles.
• The material. The material the filter is made of is an important decision, too. Media filters are at least 20 times more efficient than traditional fiberglass filters.

Are you feeling like you want to start improving your IAQ, but don’t know how to begin? Spring is a great time to start, and HVAC contractors are considered essential businesses in many states. Most credible HVAC contractors have adjusted the protocols when interacting with homeowners given the coronavirus. Consider opening a window or adding a house plant as a quick fix – or otherwise call a professional HVAC contractor that can recommend efficient whole-home ventilation and filtration solutions to help optimize the home’s fresh air supply.