The effects of novel personal comfort systems on thermal comfort and thermophysiology

Abstract

Allowing more indoor temperature variations may stimulate human physiological thermoregulation and benefit (metabolic) health. However, thermal comfort may be compromised. To investigate possible solutions for balancing thermal comfort and health, we evaluated a novel personal comfort system (PCS) in moderately drifting ambient temperatures (17-25˚C). This PCS targets the most sensitive body parts (hands, underarms and feet in cold and the head in warm conditions), leaving the rest of the body exposed to the ambient dynamic temperature. A cross-over, randomized study was conducted in an office-like laboratory. Eighteen participants (nine male and nine female) were enrolled and performed two scenarios on separate days, one with the PCS and another scenario without the PCS in 17-25˚C. Skin temperature, skin blood flow and thermal perception were measured. The skin temperature is used to indicate thermoregulation as it is an important driver for thermoregulation while skin blood flow indicates vasomotion. The results show that the designed PCS significantly affected the skin temperature of targeted body parts while it had no significant effects on the skin temperature of most non-targeted body parts. Moreover, the skin blood flows of the hands and feet were not affected by the designed PCS in 17-21˚C. On the other hand, the designed PCS significantly changed thermal sensation and improved thermal comfort in cold to neutral conditions (17-23˚C). Therefore, the PCS may maintain the effectiveness of the cold temperature drift on vasomotion and thermoregulation, while significantly improving thermal perceptions. These findings imply that the designed PCS, combined with cold ambient conditions, potentially balances thermal comfort and health in office environments.