One German school has come up with a cheap and simple DIY system to help with the air moving problem in the room during COVID-19. It was invented by a teacher's scientist husband, Frank Helleis.
In the school, above every desk, there is a clear plastic funnel attached to a narrow pipe (连接着窄小管道的塑料漏斗). All the pipes are in turn connected to one wide pipe leading to a fan (风扇) that directs the air outside through a window. Warm air breathed out by the students rises up overhead and is sucked (吸) up and pushed outside before it can spread through the room. Another window is kept half-open to allow in fresh air.
The system manages to take out over 90% of aerosols (气溶胶) from the room. It can be built with materials from a DIY store for around $235. Some people were successfully putting all the materials together in half a day. And it has been shared online for anyone who wants to use the idea.
Helleis had the idea after discussing with his team on how they could help during COVID-19. "We found the best thing to do was to take out the aerosols," he said.
Helleis says air purifiers (净化器) can be useful but are more expensive and noisier than his invention. And unlike his invention, expensive purifiers don't deal with CO2, which might cause tiredness. This gives schools a reason to keep his homemade system.
The school plans to spend the next few weekends installing Helleis' system in all the classrooms.