Measurement of Airflow around the Human Body with Wide-cover Type Personal Air-conditioning with PIV

Abstract

Many existing personal air-conditioning systems cool only specific portions of the human body in the form of spot cooling, using either cooled or fast airflow to control thermal sensation. This may cause various problems related to localized airflow, such as discomfort to the face and neck areas and dryness in the eyes. Therefore, a method is proposed in this research for task area wide-cover type personal air-conditioning that prevents the task area of a human body from being exposed to a largely irregular thermal environment. A particle image velocimeter was used in the research to measure airflow fields for conventional spot cooling and wide-cover type personal air-conditioning (PAC) around the human body. The spot cooling type PAC formed an airflow of 0.3—0.6 m/s around the area of the neck. However, the wide-cover type PAC formed a calmer airflow field of less than 0.18 m · s-1 around the human body. This is because the supply air from a wide-cover type PAC has a higher density than the surrounding air and can extensively cover the human body. Therefore, the wide-cover type PAC can minimize the potential for cold drafts to affect the human body.