To Prevent Infections Through Cooling Devices in Summer... Ventilate Like This

[Asia Economy Reporter Kim Young-won] The government has urged adherence to ventilation guidelines, warning that the use of cooling devices during the summer could increase the risk of indoor COVID-19 infections. Over the past two years, mass infections of COVID-19 have periodically occurred in multi-use facilities where many visitors gather during summer vacations and ventilation is insufficient. One example is the 2020 cluster infection case at a cafe in Paju-si, Gyeonggi-do.

In the case of COVID-19, aerosol droplets smaller than 5μm can remain airborne for extended periods and spread over distances exceeding 10 meters. Using air conditioners or other cooling devices in enclosed spaces can enable longer-range transmission, and in places like cafes where conversations occur, increased breathing volume raises the risk of airborne infection.

Following ventilation guidelines can help eliminate these airborne droplets more quickly. According to analyses by the Central Disease Control Headquarters and KICT, cross-ventilation in multi-use facilities rapidly reduces airborne droplets, lowering the likelihood of transmission. The time required for droplet contaminants to disappear decreased from over 40 minutes to around 25 minutes.

Multi-business facilities should ventilate the interior by operating air conditioners or similar devices at maximum airflow for more than 30 minutes before and after business hours, with all doors and windows open. The airflow direction should be set toward the ceiling or walls, and the intensity used weakly. Additionally, windows should be opened regularly for natural ventilation lasting at least 10 minutes. In enclosed spaces where ventilation is difficult, fans should be used to expel indoor air outside.

Where mechanical ventilation systems are installed, the intake of outdoor air should be set high to maximize ventilation with outside air, and opening windows for natural ventilation simultaneously is recommended.

At home, when operating air conditioners, ventilation should be performed up to three times a day, each time for at least 10 minutes. Opening windows and doors simultaneously to enable cross-ventilation is ideal. Using fans together can help expel harmful substances floating indoors more effectively.

When cooking, if using a kitchen hood, natural ventilation must be performed concurrently. Operating the kitchen hood creates negative pressure indoors, which can cause contaminants to enter.

Meanwhile, ventilation guidelines in overseas countries such as France, the Netherlands, and Belgium also recommend natural ventilation for 10 to 15 minutes or longer.