Development of CO₂ Concentration Prediction Tool for Improving Office Indoor Air Quality Considering Economic Cost

Ventilation is becoming increasingly important to improve indoor air quality and prevent the spread of COVID-19. This study analyzed the indoor air quality of office spaces, where occupants remain for extended periods, among multi-use facilities with an increasing need for ventilation system application. A “tool for office space CO₂ prediction and indoor air quality improvement recommendation” was developed. The research method was divided into four steps. Step 1: Analysis of indoor air quality characteristics in office spaces was carried out with a questionnaire survey and indoor air quality experiment. Based on the CO₂ concentration, which was found to be a problem in the indoor air quality experiment in the office space, Step 2: CO₂ concentration prediction tool for office spaces, which requires inputs of regional and spatial factors and architectural and equipment elements, was developed. In Step 3: Development and verification of prediction tool considering economic feasibility, the cost of energy recovery ventilation systems based on the invoices of the energy recovery ventilation manufacturers was analyzed. In Step 4: Energy recovery ventilation proposal and indoor CO₂ forecast, Office Space B, which can accommodate up to 15 people, was derived as an example of the proposed tool. As a result of the prediction, the optimal air volume of the energy recovery ventilation was determined according to the “office CO₂ prediction and indoor air quality improvement recommendations”. This study introduced simple tools, which can be used by non-experts, that are capable of showing changes in indoor air quality, CO₂ concentration and cost according to activities.