Abstract
Existing personal air conditioning (PAC) cools only specific portions of the body in the form of spot cooling using cooled or fast air flow. This encompasses various problems concerning comfort due to localized air flow causing discomfort to the face and neck areas, and dryness to the eyes. This research proposes a new task air-conditioning method to control the task area by minimizing the temperature and airflow distributions and allowing the human thermal environment to be as regular as possible, as well as preventing the human body in the task area from being exposed to a largely irregular thermal environment. This is termed a "task area wide-cover type personal air conditioning method" here. This refers to a method of air conditioning in which cooled air blown upward from a PAC unit is allowed to fall over a wide task area including the human body due to the difference in the density of the cooled air, and this minimizes the drafts. We used the PIV (Particle Image Velocimeter) and the coupled simulation of convection and radiation to examine the airflow fields for conventional spot-cooling and task area wide-cover type PAC around the human body, aimed at confirming the effectiveness of wide-cover type PAC. The wide-cover type PAC formed a calm air flow field of less than 0.18m/s around the human body, while the spot cooling type PAC formed an air current of 0.3-0.6m/s around the area of the neck. In the case of the wide-cover type PAC, the distribution of the clothes surface temperature and convective heat transfer rate etc. of the human body is smaller than in the spot-cooling PAC.
