Airflow cleans up the particulate matter within the classroom

According to the WHO, about 7 million folks die every year attributable to air air pollution. Particulate matter (PM) triggers inflammatory responses within the human physique, inflicting bronchial asthma and different respiratory and cardiovascular ailments. It is extra deadly for younger and rising college students. The Korea Institute of Civil Engineering and Building Technology (KICT) has diminished time required to take away particulate matter from the classroom by greater than 30% by optimizing the areas of provide and return diffusers for air equipped into the classroom.

Reducing Particulate Matter has been a worldwide activity. In 2018, the Korean Ministry of Education (MOE) introduced undertaking designed to tighten the fantastic particles (PM_2.5) requirements for school rooms to the annual common of 15㎍/㎥. The MOE has strived to take away particulate matter from school rooms, finishing its drive to put in air purifiers in all elementary schools throughout the nation final yr.

As a part of these efforts, a analysis workforce at KICT led by Dr. Choon-Man Jang developed a central heating, air flow and air-conditioning system (HVAC) system outfitted with HEPA filters for elementary colleges in Korea.

This central HVAC requires an air dealing with unit (AHU) to be put in for every flooring of the college to provide clear air to school rooms by means of ducts. Supply diffusers related to ducts provide clear air into every classroom, whereas the indoor air polluted by college students’ indoor actions and inflows of particulate matter is discharged by means of return diffusers after which purified by the AHU.

Dr. Jang’s workforce utilized three-dimensional numerical simulation to design the optimum positioning of provide and return diffusers. In order to display efficiency on the identical scale as a real-life college facility in Korea, the analysis workforce constructed a “full-scale school surroundings efficiency test-bed” and carried out experiments.

Tests had been carried out to validate the efficiency of airflow areas—higher provide diffusers and decrease window-side return diffusers—which had been optimized by means of numerical simulation. Results present that the time it takes to take away particulate matter (PM_2.5) from the validation requirement of 800 m³ per hour has been diminished by greater than 30%. This enchancment has been achieved by bettering the circulation of indoor airflow contained in the classroom and consequently lowering air stagnation.

The distributions of streamlines for higher and flooring return diffusers present that the airflow discharged from the higher provide diffusers doesn’t attain the ground absolutely however will get out by means of the return diffusers on the ceiling. When flooring return diffusers are used, nonetheless, airflow from the higher provide diffusers reaches the ground the place it’s evenly distributed. This signifies that optimum airflow management by means of the optimization of the areas of return diffusers allows the environment friendly elimination of particulate matter. Furthermore, it maintains the even distribution of indoor airflow.

This composite system could be put in not solely in colleges however can be utilized for a spread of functions, together with different instructional amenities and nursing amenities. One of its largest benefits is that it could possibly take away indoor particulate matter sooner than different indoor air flow techniques.

Dr. Choon-Man Jang mentioned, “Indoor particulate matter in schools directly affect students’ health, so it is very important to reduce the time it takes to remove particulates through airflow optimization.”

Provided by
National Research Council of Science & Technology