  In this paper, we investigate the feasibility, robustness and optimization of
introducing personal comfort systems (PCS), apparatuses that promises in energy
saving and comfort improvement, into a broader range of environments. We report
a series of laboratory experiments systematically examining the effect of
personalized heating in neutralizing individual, spatial and temporal
variations of thermal demands. The experiments were conducted in an artificial
climate chamber at -15 degC in order to simulate extreme cold environments. We
developed a heating garment with 20 pieces of 20 * 20 cm2 heating cloth
(grouped into 9 regions) comprehensively covering human body. Surface
temperatures of the garment can be controlled independently, quickly (within 20
seconds), precisely (within 1 degC) and easily (through a tablet) up to 45
degC. Participants were instructed to adjust surface temperatures of each
segment to their preferences, with their physiological, psychological and
adjustment data collected. We found that active heating could significantly and
stably improve thermal satisfaction. The overall TSV and TCV were improved 1.50
and 1.53 during the self-adjustment phase. Preferred heating surface
temperatures for different segments varied widely. Further, even for the same
segment, individual differences among participants were considerable. Such
variances were observed through local heating powers, while unnoticeable among
thermal perception votes. In other words, all these various differences could
be neutralized given the flexibility in personalized adjustments. Our research
reaffirms the paradigm of "adaptive thermal comfort" and will promote
innovations on human-centric design for more efficient PCSs.
