Ventilation is key to fight Covid-19 transmission
With rapidly increasing numbers of Covid-19 patients all over the world the awareness of airborne transmission increases too. Most of us know by now how to protect ourselves from the virus, but still very few people are aware that ventilation and air quality really matter.
We wrote a blogpost on how to protect yourself from Covid-19 infection a few weeks ago, and please take a look at it if you havenât already done so.
With colder temperatures and the holiday season approaching, it is very important to consider all precautions for a safe and healthy time together. A troublesome finding from recent research is that Covid-19 is transmitted also via the air in the form of small droplets called aerosols. They move around due to a mix of thermal conditions as well as the general air direction in the room. This can be over quite long distances.
Healthcare is struggling with high patient flow with more and more people that are in need of care and treatment. Hospital staff are equipped with sterile and protective clothing, including face mask and faceshields. However, a study published in December 2020 reveals that faceshields may not protect the carrier from aerosols due to vortex rings. The aerosols from sneezing or coughing can be transported from the infected person and transfer to the protected personâs airways, if inhalation happens when the aerosol reaches the shield. See the airborne transmission of particles in the vortex in the video below.
Credit: Fujio Akagi, Isao Haraga, Shin-ichi Inage, and Kozaburo Akiyoshi
One way to minimize this airborne risk of infection is to dilute the concentration of aerosols by increasing the air changes per hour (ACH). You should also ensure that the air supplied to the room is clean by using proper air filters. HEPA filters are some of the densest filters available, with a filtration of more than 99.97% of the particles. However, HEPA is a very thick filter and you need to ensure that your ventilation systems are powerful enough to push air through these filters.
To complicate matters, it is not only expensive to increase the air changes per hour, but for most buildings you have to cool or heat the air brought in from outside to make the indoor climate comfortable. So just increasing number or air changes per hour may be costly, but luckily it is not all about air changes! The direction of the air is also very important in terms of efficiency. With a temperature controlled air flow the air is falling downwards with gravity, and swept away along the floor. This is extremely efficient, as shown in several research articles.
Moreover, the technology behind Temperature controlled Air Flow (TcAF) was invented to eliminate airborne bacteria inside occupied rooms where there is lots of actions, which is very different from laminar airflow systems designed for cleanrooms where people are dressed in space suits and move very slowly. The strong unidirectional airflow from TcAF makes sure that aerosols and particles are pushed downwards and won´t swirl around and infect people.
If you are as concerned as we are how the virus can spread not only short distances on droplets but also further as aerosols, we want to work with you and put science into action using a proven and scientifically validated technology.
Contact us for more information about how to create a healthy and energy-efficient indoor environment in your facility â free of charge!
Read the recent study here
