A Numerical Model of Carbon Dioxide Concentration Measurement in a Room with an Opened Ventilation System

Wasu Timpitak,Nopparat Pochai

doi:10.13189/eer.2021.090302

Abstract

A vast number of patients visit the facility every day, causing a major air pollution issue that may pose a risk of exposure of respiratory infectious diseases in outpatient rooms and harm human health. TB, COVID-19, MERS, and SARS are dangerous communicable diseases that transmit from person to person through the air or aerosol in a variety of forms, such as coughing, spitting, sneezing, speaking, or through wounds. COVID-19, TB, MERS and SARS are risks and the chances of success toward lethal infection make more patients ill in the hospital. We should also be notified of the care and control of these diseases. As a result, effective air quality monitoring is needed to monitor and reduce the potential for infected air, such as carbon dioxide (CO<sub>2</sub>) concentrations. Measuring and controlling carbon dioxide in a hospital with a ventilation system where the number of patients in each room varies in time is challenging. In this research, the numerical model of carbon dioxide concentration measurement in a space with an opened ventilation system is proposed. The model sets the concentration of carbon dioxide at any point when the number of people and the rate of ventilation varies. The classical fourth-order Runge-Kutta method is employed to approximate the model solution. There are many cases of scenarios for improving air quality in the proposed simulations. In the air quality management process, the proposed model provides a balance between the number of persons allowed to stay in the room and the capacity of the air ventilation system.

Highlights

In [1],[2],[3],[4], and [5], they proposed that infectious disease of airborne such as tuberculosis (TB) spread in several gathering locate areas with infectors and poor ventilation per person rates, [1],[2],[3],[4], and [5]
In [6], and [9], they proposed carbon dioxide be used as an indicator of air quality indoor, built on the notion that people release carbon dioxide at a rate dictated by their body weight and bodily movement, and that levels of carbon dioxide indoor are measured by fresh air clearance
In [6],[10], and [9], they propose carbon dioxide concentration in the air of approximately 400 ppm in a room, but when but people enter it, exhaled air concentration begins to rise, depending on the rate of ventilation per person, the length of the room, and the number of persons who are present in the room, because of their oxygen intake, respiratory quotient, and bodily movement, person in the room add to the rise in rebreathed air

Summary

Introduction

In [1],[2],[3],[4], and [5], they proposed that infectious disease of airborne such as tuberculosis (TB) spread in several gathering locate areas with infectors and poor ventilation per person rates, [1],[2],[3],[4], and [5]. 108 A Numerical Model of Carbon Dioxide Concentration Measurement in a Room with an Opened Ventilation System tagious airborne particles inside the nuclei with droplets that can stay airborne for extended periods and infect a susceptible person when inhaled. In [17], and [12], they proposed that infectious particles with a key size range of 1 Mm to 5 Mm had a higher possibility of reaching and depositing on the alveolar area than those with sizes greater than 5 Mm, which are confined in the upper respiratory tract This means that not all infectious particles absorbed from the air will reach or be kept at the site of infection. Where C is the concentration of indoor air exhaled (ppm), p is the rate of breathing(L/s) for each person in the room and Ca is the carbon dioxide fraction included in inbreathed air.

Numerical technique

Numerical experiments and results

Discussion

Conclusion