Desktop “air curtains” as an indirect virus barrier
Air curtains – artificially created streams of moving air – which are used to protect patients in operating rooms or to prevent the spread of contaminants, may be a solution for tight, closed spaces when social distancing is not possible. Researchers at Nagoya University in Japan have tested such a system, noting efficient deflection of aerosol particles without passing through the air curtain.
An air curtain, or air door, is a fan-powered ventilation system that creates an air seal over an entryway. While efficient in healthcare settings, smaller devices using this technology gradually lose their efficiency and leak infected aerosol particles into the surrounding environment.
The Desktop Air Curtain System (DACS) developed at Nagoya University contains a discharge and suction port to help address this problem.
In short, a generator at the top of the DACS produces the airflow, which is guided to the suction port at the bottom of the device. This prevents airflow dispersion, leading to the collection of all the aerosol particles at the suction port. A high-efficiency particulate air (HEPA) filter can be installed inside the suction port for air purification.
In tests, aerosol particles approaching the DACS abruptly bent toward the suction port, signifying that air curtain flow fully blocked all incoming aerosol particles. When the researchers placed the mannequin’s arm through the DACS to imitate a blood-collection scenario, they found the airflow above the arm was disrupted. However, the aerosol blocking performance remained unaffected.
“We envisage this system will be effective as an indirect barrier for use in blood-testing labs, hospital wards, and other situations where sufficient physical distance cannot be maintained, such as at a reception counter,” said Kotaro Takamure, an academic researcher at the university.
The researchers are developing an accompanying virus inactivation system equipped with ultraviolet (UV) light that connects to the suction port – after air is sanitised with the UV light, it can be recirculated to maintain airflow of the air curtain and air pressure in a room. The researchers are also looking at lowering the suction port, so the arm can be placed below the heart for proper blood collection.
