COVID-19: Ventilation May Be Hidden Key To Reducing Spread

Germany has made the airing out of closed spaces a centerpiece of its recommendations for limiting contagion. Others, including the CDC, are also touting the benefits.

Japan has asked its population to stay away from closed and crowded spaces
Japan has asked its population to stay away from closed and crowded spaces
Bertrand Hauger

After months of fighting the spread of COVID-19, a number of protective measures have made their way into our daily routine: We wash our hands, sneeze into our arm, wear a mask, social-distance and elbow-bump. But another potentially crucial weapon in combatting the virus has gone underreported in many parts of the world: ventilating closed spaces.

Ventilation's biggest fan: Though the science is still divided, ventilation has moved to the center of government recommendations in a country respected for its pragmatism and scientific rigor: Germany.

Doing the heavy Lüften Among the lesser-known stereotypes about Germans is their love of fresh air. True to linguistic form, they even have a name for it: Stosslüften, or the act of airing a room several times a day. Thus her fellow Germans weren't surprised when Chancellor Angela Merkel herself advertised ventilating as "one of the cheapest and most effective ways' of containing the spread of the virus.

Germany's handy acronym against coronavirus, AHA (Abstand, Hygiene und Alltagsmasken: Social distancing, Hygiene and Facemasks) has recently gained two letters: enters AHACL, with C and L standing respectively for Corona-Warn-App, the government's prevention app, and Lüften — airing.

  • The update is based on the belief that "regular ventilation in all private and public rooms can significantly reduce the risk of infection," as Münich-based Merkur daily reports.

  • With winter around the corner, opening windows to fend off the pandemic is becoming less of an option. Germany's federal government is about to invest a half-billion euros in the renovation of ventilation systems in schools and public buildings, as German daily Die Welt reports.

    → The goal: retrofitting old AC systems so that they can use as little circulating air as possible, and as much outside air as possible, therefore avoiding recycling potentially contaminated air while limiting heat loss during cold months.

Open window in a classroom in Stuttgart, Germany — Photo: Christoph Schmidt/DPA/ZUMA

An idea is spreading: For months, evidence has been mounting that the virus can spread by microparticles and aerosols. At the beginning of October, the Centers for Disease Control and Prevention published guidelines on Oct. 5, declaring the novel coronavirus is indeed airborne. But Germany, it turns out, is not alone in pushing the merits of airing:

  • The Spanish government has issued an extensive series of specific guidelines "on the use of air conditioning and ventilation systems to prevent the spread of COVID-19" covering aspects such as airflow rates, humidity levels and the replacement of air filters. Another guide aimed specifically at the country's schools, recommends ventilating classrooms five to six times per hour — never mind lower outside temperatures, the guide going as far as to recommend students "wear warmer clothes', the Madrid daily ABC reports.

  • In the U.S., the craze surrounding high-end air filtration systems is "like toilet paper in April times two," CNBC quotes the CEO of a Texas AC company as saying, with HVAC (Heating, Ventilation and Air Conditioning) systems selling like hotcakes.

  • In France, "airing rooms for 10 minutes, three times a day" is now part of the country's mesures barrières to stop the spread, as shown on government website — a matter of particular importance for the French who have just entered their second nationwide lockdown.

  • Japan too, focused on ventilation, as sociologist Zeynep Tufekci writes in The Atlantic. The government has asked the population to stay away from places that may gather "the three Cs': Crowds, Closed spaces, close Contact.

The takeaway Airborne? Well, it's complicated. Although many questions about the pandemic remain open, according to Dr. Bill Schaffner, an epidemiologist at Vanderbilt University, the spread of coronavirus through aerosols is "rather uncommon." The virus, it seems, spreads mainly through direct contact and via droplets that are significantly bigger and therefore not subject to airborne transmission per se.

At the same time, as Tufekci writes, super-spreading events seem to overwhelmingly occur when three conditions are reunited: 1) many people 2) especially in a poorly ventilated indoor setting 3) and especially not wearing masks.

  • In other words, though COVID-19's airborne risks may be relative, ventilating efforts still make sense — that is, if done in conjunction with other prevention methods. Which means that for now, the best solution may rest not with the Germans, but with their neighbors: the Swiss cheese approach, where each holey slice of cheese serves as an additional barrier against the spread.
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In Argentina, A Visit To World's Highest Solar Energy Park

With loans and solar panels from China, the massive solar park has been opened a year and is already powering the surrounding areas. Now the Chinese supplier is pushing for an expansion.

960,000 solar panels have been installed at the Cauchari park

Silvia Naishtat

CAUCHARI — Driving across the border with Chile into the northwest Argentine department of Susques, you may spot what looks like a black mass in the distance. Arriving at a 4,000-meter altitude in the municipality of Cauchari, what comes into view instead is an assembly of 960,000 solar panels. It is the world's highest photovoltaic (PV) park, which is also the second biggest solar energy facility in Latin America, after Mexico's Aguascalientes plant.

Spread over 800 hectares in an arid landscape, the Cauchari park has been operating for a year, and has so far turned sunshine into 315 megawatts of electricity, enough to power the local provincial capital of Jujuy through the national grid.

It has also generated some $50 million for the province, which Governor Gerardo Morales has allocated to building 239 schools.

Abundant sunshine, low temperatures

The physicist Martín Albornoz says Cauchari, which means "link to the sun," is exposed to the best solar radiation anywhere. The area has 260 days of sunshine, with no smog and relatively low temperatures, which helps keep the panels in optimal conditions.

Its construction began with a loan of more than $331 million from China's Eximbank, which allowed the purchase of panels made in Shanghai. They arrived in Buenos Aires in 2,500 containers and were later trucked a considerable distance to the site in Cauchari . This was a titanic project that required 1,200 builders and 10-ton cranes, but will save some 780,000 tons of CO2 emissions a year.

It is now run by 60 technicians. Its panels, with a 25-year guarantee, follow the sun's path and are cleaned twice a year. The plant is expected to have a service life of 40 years. Its choice of location was based on power lines traced in the 1990s to export power to Chile, now fed by the park.

Chinese engineers working in an office at the Cauchari park


Chinese want to expand

The plant belongs to the public-sector firm Jemse (Jujuy Energía y Minería), created in 2011 by the province's then governor Eduardo Fellner. Jemse's president, Felipe Albornoz, says that once Chinese credits are repaid in 20 years, Cauchari will earn the province $600 million.

The Argentine Energy ministry must now decide on the park's proposed expansion. The Chinese would pay in $200 million, which will help install 400,000 additional panels and generate enough power for the entire province of Jujuy.

The park's CEO, Guillermo Hoerth, observes that state policies are key to turning Jujuy into a green province. "We must change the production model. The world is rapidly cutting fossil fuel emissions. This is a great opportunity," Hoerth says.

The province's energy chief, Mario Pizarro, says in turn that Susques and three other provincial districts are already self-sufficient with clean energy, and three other districts would soon follow.

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