But again, the core strategy is to keep viruses out of our air so they stay out of our sinuses, throats and lungs so we don’t get sick. Viruses move around when we sneeze or cough - they spray out (20’ or more) - then stay in the air, or land on surfaces and dust. They can move around when we do things that disturb dust like walking on carpet, vacuuming and sweeping. When we do these things and viruses are in the air on in our dust we will likely end up breathing viruses in because our bodies don’t filter our particles as small as most viruses.

As for the Novel Coronavirus specifically, let’s take a look back at Dr. Allen’s NYT piece we mentioned earlier:

Current guidelines are based on evidence that the virus is transmitted primarily through respiratory droplets — the large, sometimes visible droplets expelled when someone coughs or sneezes. Thus the recommendation to cover your coughs and sneezes, wash your hands, clean surfaces and maintain social distancing. But when people cough or sneeze, they expel not only large droplets but also smaller airborne particles called droplet nuclei, which can stay aloft and be transported around buildings. Previous investigations of two recent coronaviruses showed that airborne transmission was occurring. This is supported by evidence that the site of infection for one of those coronaviruses was the lower respiratory tract, which could only be caused by smaller particles that can be deeply inhaled. This brings us back to buildings. If managed poorly, they can spread disease. But if we get it right, we can enlist our schools, offices and homes in this fight.





As of March 13th, a new report of findings by a research team at UCLA discovered that the Novel Coronavirus can live on certain surfaces, like stainless steel, for up to 72 hours in laboratory conditions. The same study found that the virus’ particles can remain viable floating in the air for several hours, which creates what’s called aerosolized transmission. What isn’t well understood yet in this research is exactly how many of those viral particles are necessary for an infectious dose, nor exactly how the virus will behave in non-laboratory conditions.

So what are some best practices we can employ in our buildings/designs to help keep indoor pollutants like viruses away?

Ventilation

Ventilation is crucial. Bringing in more filtered outdoor air in buildings heating/cooling systems (or opening windows in buildings that don’t) helps extract airborne contaminants from the building, making infection less likely. For years, we have been doing the opposite: sealing our windows shut and recirculating air. Just look at the residential code requirements for ventilation (or even scarier, look at the enforcement). The result are homes, schools, and office buildings that are chronically under ventilated. This not only gives a boost to disease transmission, including common scourges like the norovirus or the common flu, but can also significantly impair cognitive function.

If you don’t have mechanical ventilation in your home, make yourself a calendar reminder to open up the windows a few times per day/evening (whenever you’re home) for as long as you can. Obviously, depending on your climate this may prove difficult for thermal comfort or humidity introduction into your space, but still generally a good idea.

Back to the good Dr. Allen:

A study published just last year found that ensuring even minimum levels of outdoor air ventilation reduced influenza transmission as much as having 50 percent to 60 percent of the people in a building vaccinated.

Let that sink in.

Filtration

Keep viruses out of the air by using an appropriate type of filter. Especially for buildings without mechanical ventilation systems, or if you want to supplement your building’s system in high-risk areas, portable air purifiers can also be effective at controlling airborne particle concentrations. Most quality portable air purifiers use HEPA filters, which capture 99.97 percent of particles.

A HEPA filter lets air through but traps viruses (and other chemicals plus, bacteria, pollens and mold). Using a HEPA air filter connected to your central air/heat system can drastically decrease indoor air pollutants. This kind of air purification will reduce the viruses in the air, not just swoosh them around the room. However, remember that simply replacing a non-HEPA with a HEPA filter in existing equipment may worsen the problem. Make sure your system can accommodate the air flow needs of a HEPA filter. If your system can’t, you can explore a more decentralized approach through portable room air cleaners instead. Take a look at The Wirecutter’s recent review of portable room air cleaners for a pretty comprehensive list of consumer grade pieces of equipment you can buy online today.

Humidity & Temperature Control

Humans and viruses prefer different indoor temperatures and humidity to thrive. Use this to your advantage. Keep it dry. If you have a damp indoor environment due to the general climate, excessive cooking, washing, or bathing use a dehumidifier to control the indoor moisture. Keep it warm. Viruses thrive in cold environments. Setting your thermostats above 65 degrees will decrease the lifespan of most viruses.

And finally, we’d like to bring it back to Dr. Allen’s recommendations for operations:

Last, coronavirus may spread from contaminated surfaces — things like door handles and countertops, elevator buttons and cellphones. Frequently cleaning these high-touch surfaces can also help. For your home and low-risk environments, green cleaning products are fine. (Hospitals use E.P.A.-registered disinfectants.) Whether at home, school or the office, it is best to clean more often and more intensely when infected individuals are present. Limiting the impact of this epidemic will require an all-in approach. With significant uncertainty remaining, we should be throwing everything we have at this highly infectious disease. That means unleashing the secret weapon in our arsenal — our buildings.

Remember that we’ll get through this. It’s an inflection point for us to realize how interconnected we are on the planet together. And remember, the same principles of design that create healthy buildings are almost always the same principals that create resilient, low carbon buildings.

Find your calm. Practice good personal, social, and building hygiene. Let’s use this new awareness to help us design better spaces to prevent future, potentially much worse outbreaks.



