A study on changes in occupants' thermal sensation owing to CO₂ concentration using PMV and TSV

Indoor environmental quality (IEQ) factors must be controlled appropriately to ensure the health and work efficiency of building occupants. To accurately evaluate IEQ factors, the correlations between factors must be considered, rather than classifying each factor independently. CO₂ concentration, which indicate indoor air quality, are related to respiration. Given that CO₂ concentration influence occupants' thermal sensation, it is difficult to ensure thermal comfort in addition to indoor air quality, solely by performing thermal environment control in a space that does not have suitable ventilation. This study used the Discrepancy between TSV and PMV (DV) in each CO₂ concentration section to analyze the effect of CO₂ concentration on thermal comfort evaluations in university library. Based on this analysis, this study proposes a novel air conditioning control method that considers the indoor air quality and thermal environment together. This study also used simulations to analyze the indoor thermal environment and energy consumption that occurred as a result of the ventilation control strategy when the novel control method was applied. The results showed that occupants' thermal sensation became more sensitive to heat as the CO₂ concentration increased, and it is energy efficient to regulate occupants’ thermal sensation by introducing suitable ventilation such as the Demand Controlled Ventilation (DCV) control method when applying novel control method during intermediate seasons. •Evaluation of indoor environmental quality must include the correlation of factors.•CO2 concentration plays a key role in occupant's thermal sensation.•Occupants become more sensitive to thermal discomfort as the CO₂ concentration increases.•CO2 level monitoring may result in an increase in overall HVAC energy efficiency.