Ventilation Cfd Analysis at an Classroom as a Tool for Air Safety Verification under Covid19 Context, a Case Study

ABSTRACT

The COVID 19 pandemic has struck the global economy and slowed down human activity. Paraguay, a small South-American country, was not an exception. This work results from the urgent need to reopen universities, schools, and other academic institutions to resume teaching activities in light of restrictive access to online learning in Paraguay. In order to contain the spread of this virus, school activities such as course lectures were placed on hold indefinitely. Inappropriate airflow in an enclosed space is one of the main factors in the spread of this virus. When combined with personal protective equipment, proper air ventilation and air replacement can significantly reduce this airborne virus's spread. Potential sources of contaminant accumulation are stagnant locations of air in a closed volume. It is, therefore, essential to first identify these hot spots. Utilizing computational tools, such as CFD, an airflow analysis can be conducted to see any potential stagnant point. In the case of a classroom, it will then allow proper airflow by avoiding stagnant points by moving furniture, equipment, and chairs in combination to adding walls and opening windows and doors. This type of CFD study will set the benchmark for future classroom layout standards in this pandemic background. The work discussed here is a case study on a 300 student classroom at the Faculty of Engineering at the National University of Asuncion. The CFD results showed detailed infounation on flow patterns and velocity profiles in the analyzed classroom environment and air cycle and exhaust results. The six air conditioning systems blowing 300 CFM each, combined with eight fans installed at the ceiling, forced air to recirculate and helped to remove old air to the windows and suction some new air from doors. This helped university administrators to reopen some class areas and keep their faculties and students safe for lectures. It is important to remark here that air reposition could be measured, showing 200 CFM air removal in this first simulation run. Further analysis with a different internal layout will be needed to see if any improvements can be made. It is expected to have a much better air removal by adding a localized exhaust fan. This work suggests the location of each location's outlet points and flows capacity to ensure proper ventilation is achieved in this particular case study. Other academic institutions are showing interest in implementing this computational tool to design classroom layout as well as ventilation schemes.