Supported by
By Heather Murphy
Although it is an essential role in our lives, air is not something we should spend a lot of time thinking about. It’s so simple to take for granted. Unlike water, we don’t want to fill a cup to consume it. If some escape from the room, others will locate their way, open the door or not.
“If you’re comfortable, you don’t know,” said Wade H. Conlan, a mechanical engineer who evaluates ventilation systems for Hanson Professional Services.
But like so many small luxuries we once took for granted, our days of air satisfaction can be told. Because an increasing number of scientists are convinced that a significant amount of coronavirus transmission occurs through the air in indoor spaces, and that poor ventilation increases the risk.
Not everyone has the capacity or resources to make adjustments to air circulation in a home or office. But scientists and engineers say it’s valuable to figure out the basics of how airflow works, in case there’s a relatively undeniable replacement that can keep you a little safer.
Scientists continue to examine the exact way viral debris circulates in a room when an inflamed user speaks, sings, exhales, or eats. Studies from previous cases have shown that it is complicated. If there is an easy-to-understand precept in which aerosol scientists and engineers have come to an agreement with this: the more outside air there is in a room, the greater the dispersion of this cloud of viral debris that can persist. And one of the most reliable and economical tactics for air entering a room is to open a window.
“If you don’t know if the position is well ventilated, but you have the option to open a window, I would,” said Shelly Miller, a professor of mechanical engineering at the University of Colorado at Boulder. This, he said, or exits temporarily if he moves away from an internal position with other people.
The outside air that enters will eventually update the indoor air, according to José-Luis Jiménez, aerosol scientist at the University of Colorado at Boulder.
“The more outside air it has, the more the virus dilutes,” said Dr. Jimenez, who among scientists and engineers sent a letter urging the World Health Organization to recognize that the airborne transmission of the new coronavirus is a threat. indoors.
If you need to accelerate the outdoor air in a room, you can also take a fan, place it in a window and blow it out, Dr. Jimenez said. When an amount of air comes out, the same amount of air returns: it is a constant volume. Therefore, the fan deserves help to suck in the same amount of outside air.
If you have air conditioning in your home, no one says you should give it up completely. In case of suffocation, air conditioning may be essential not only to help it function, but also to warm the body.
But if you’re going to spend time in a cool area with other people, it would possibly be helpful to know a little more about the new air you breathe. Basically, all air conditioning falls into one of 3 categories.
The unit cools the interior and air.
The unit cools and recirculates the indoor air.
The unit is based entirely on the suction of the outside air. (These are rare hospitals and outdoor labs)..
Centralized air systems, such as those that are not unusual in workplace constructions, dormitories, and some giant apartment constructions, fall into the first category. Dr. Jimenez and other construction scientists concerned about coronavirus prevention are lately advising commercial and construction homeowners with Category One systems to adjust the ratio to attract more outside air, a business that can be costly. Take a casino in Las Vegas, which is great enough for other people to play indoors while outside it does 120 degrees Fahrenheit. Cooling this hot outdoor air will charge more than recirculation of the already new indoor air. But since keeping customers healthy is also a priority, more people are willing to reconsider their approach, Dr. Jimenez said.
Few of us have the ability to adjust our air-conditioning in this way. Most window units sitting with their rears facing the outdoors, for example, fall into category two. Instead of pulling in outdoor air, they are dumping heat from the room outdoors, said William Bahnfleth, a professor of architectural engineering at Penn State’s Institutes of Energy and the Environment.
If you live alone or with others, you’re not sure it’s contagious, those outfits are fine. But if you give in to organize this birthday dinner for your parents, or if your child hasn’t been so strict in staying at home, remember that “any virus you provide will mix” with the recirculated air inside, Dr. Jimenez told me. .
So, if you want to get people, it may be more productive to go back to Rule 1: if in doubt, open the windows. Or better yet, get out.
So what do you do if you’re stuck with a unit that basically recirculates the internal air and it’s unrealistic to open the window? That’s where clearing comes in. Proper clearance is as effective as sucking outdoors, said Dr. Edward A. Nardell, a professor at Harvard Medical School who has written about the role of air conditioning in the spread of airborne diseases.
In addition to dust, pollen, kitchen odors, tobacco smoke and chemicals, filters can capture viral waste from the air. Some filters pass directly to air conditioning equipment and central air systems. Others are designed to be autonomous. MERV and HEPA are two qualified types that are highly reliable.
MERV clearings are evaluated on the basis of the power with which they dispose of waste within a wide variety of air length. ASHRAE, a professional air conditioning, heating and cooling engineering company, recommends MERV thirteen onwards to eliminate coronavirus, said Dr. Bahnfleth, who heads the group’s epidemic working group. That’s what Dr. Bahnfleth has in his own home. Any removal of HEPA is even more effective than removing MERV with the highest rating, he added, so they capture the coronavirus debris well.
Many central air systems are designed to incorporate specialized cleaning outlets. But not everyone can take care of the complex maximum clearings. Lower-rated clearings can still be helpful, Conlan said. it’s not that they’re never going to catch smaller particles; they probably wouldn’t do it that often. Window sets are sometimes designed for comfort, not health, and have even clearer limitations.
For those who can do it, or pressure their employers or owners to buy them, an independent HEPA compensation is a smart choice, Dr. Bahnfleth said. Some are designed for larger spaces than others. The key, Dr. Jimenez added, is to choose one that removes all air from the room at least twice an hour.
Keep in mind that if an air filtration formula seems too smart to be true, your instincts may be right. Some of them seem to depend on dubious marketing and science, Dr. Jimenez said.
Now that you’re an air expert, it’s possibly tempting to think you know how to position yourself in the safest position in a place to eat or another indoor area where you can find an explanation of why you are.
But even experts can’t seamlessly practice the easiest location, said Andrew Persily, who oversaw the progression of an online tool to estimate exposure to infectious sprays in rooms and buildings as head of the Energy and Environment Division of the National Institute of Standards and Technology. .
“Depending on the airflow configuration and where the aerosols are released, there may be spaces in the room that result in a higher exposure than others,” he said. “It’s hard to predict.”
It is also difficult to estimate the number of other people in a given space. After all, it only takes one inflamed user to make others sick. If you have a carbon dioxide detector, you can consult a strategy used in the past to control the spread of TB and use it to inform you, Suggests Dr. Miller. If the CO2 grades are above 1,000 servings consistent with millions, it would be wise to decrease the number of other people in the indoor space, increasing the amount of outside air or both, he said.
Another is to look around. Do you see other people? If so, go.
Advertising