Effect of turbulent intensity on human thermal sensation in isothermal environment

Air movement can improve thermal comfort in warm conditions, but it can also cause uncomfortable drafts feelings. This study focuses on the effects of turbulent air on human thermal sensations by investigating the preferred air velocity within the temperature range of 26°C to 30.5°C at two relative humidities of 35% and 65% and two turbulent intensities of 25% and 40%. Subjects in an environmental chamber were allowed to adjust air movement as they pleased while answering a series of questions about their thermal comfort and draft sensation. The results show that the higher turbulent intensity can improve human thermal sensations and reduce the risk of feeling a draft in a warm isothermal environment. The concept of draft is expanded and a new PDV model is presented to predict the percentage of people feeling drafts in warm isothermal conditions.