Personal Air Conditioning Research Articles

Clarifying Optimum Setting Temperatures for In-Flight Personal Air Conditioning System Considering Individual Thermal Sensitivity Characteristics

The number of people who use airplanes has increased year by year. However, most passengers have a feeling of discomfort during a long-distance flight. One of the factors is the lack of temperature control in the cabin. If air conditioning control can be adjusted to each passenger’s thermal sensation, the whole comfort in the cabin would be improved. Therefore, a personal air conditioning control method is required for airplanes. In order to implement personal air conditioning adapted to individual thermal sensation, this study proposes a seat-type air conditioning system that adjusts the temperature to each part of the body and aims to clarify the appropriate temperature setting in consideration of individual thermal sensation. As a result, the appropriate degree of temperature setting change was clarified based on the thermal sensation index. It was found that changing the temperature setting by 2.5 °C per scale of the thermal sensation improved the passenger’s comfort. Furthermore, people who tend to feel cold were found to be more sensitive to temperature changes. It is concluded that personalized air conditioning is possible based on individual thermal sensitivity characteristics. For prospects, it is desirable to study a system that automatically predicts the thermal sensation taking into account individual thermal sensitivity characteristics.

Subject experiment on personal air-conditioning airflow using a vortex ring

A personal air conditioning system using vortex rings, which are characterized by their linearity and low diffusivity, is developed in this study. The authors have clarified the characteristics of the vortex ring airflow by LES (unsteady CFD) and full‐scale experiments. However, the airflow type and worker's comfort using vortex rings as an air conditioning system has not been clarified yet. As a result of the subject experiments, it became clear that air conditioning with vortex rings cooled the subjects better than conventional air conditioning and improved their sense of comfort with respect to the airflow. In addition, it was found that airflow to the neck was more effective since the subjects were less likely to feel the airflow at the top of the head due to the resistance of the hair on the head. The effectiveness of the vortex ring as a personal air conditioning system was clarified, enabling relaxation of the room temperature setting. The comfortability of the airflow sensation provided by the vortex ring was also examined when further airflow was given.

Effects of Personal Air-conditioning System on Attenuating Mental Fatigue

Effects of Personal Air-conditioning System on Attenuating Mental Fatigue

Performances of machine learning algorithms for individual thermal comfort prediction based on data from professional and practical settings

Individual thermal comfort prediction models based on real-time monitoring parameters could improve the efficiency of personal air conditioning systems. However, there is a contradiction between accuracy and cost/convenience to acquire input data for individual thermal comfort prediction models. In previous studies, the performance of these models was examined using input data from either professional or low-cost devices, but they have not been compared with each other. In this study, 32 subjects with different individual features participated in climate chamber experiments with air temperatures ramp between 18 and 34 °C in summer. Commonly-used machine learning (ML) algorithms, e.g. Support Vector Machine, Decision Tree, K-Nearest Neighbors (KNN), Discriminant Analysis and ensemble methods, were used to examine two kinds of input data: the professional setting with 10 predictors include multiple personal features and high accuracy skin temperatures (±0.15 °C), and the practical setting with 5 easier obtained predictors include infrared skin temperatures (±1 °C). Results showed the overall accuracies of ML algorithms were generally higher by 0.4%–12.3% using the data in professional setting than that in practical setting. Comprehensive consideration, the optimized Cosine KNN (an accuracy of 83.6%, a precision of 89.7%, a recall of 84.3% and AUC = 0.86) and ensemble of Subspace KNN (an accuracy of 75.4%, a precision of 79.6%, a recall of 82.7%, and AUC = 0.87) were the best ML algorithms for professional and practical settings, respectively. The sensitivity analysis showed the skin temperatures were important predictors, while the age was a more important feature in practical setting then professional setting. This study could provide useful information for the selection of features and machine learning algorithms for individual thermal comfort prediction in actual buildings.

Clarifying Optimum Setting Temperatures and Airflow Positions for Personal Air Conditioning System on Flight

In recent years, the demand for air travel has increased and many people have traveled by plane. Most passengers, however, feel stressed due to the limited cabin space. In order to make these passengers more comfortable, a personal air-conditioning system for the entire chair is needed. This is because the human body experiences discomfort from localized heating or cooling, and thus, it is necessary to provide appropriate airflow to each part of the body. In this paper, a personal air-conditioning system, which consists of six vertically installed air-conditioning vents, will be proposed. To clarify the setting temperature of each vent, the airflow around the passenger and the operative temperature of each part of the body is investigated using fluid simulation. In the simulation, the ideal temperature for each part of the body is defined and compared with the operative temperature to verify how close both temperatures are, resulting in determining the ideal setting temperature. The simulation result shows, that most parts of the body reach their ideal temperatures. In addition, the optimum setting temperature and position of each air-conditioning vent, which contribute to maintaining the thermal comfort of the human body on the plane, is clarified.

Study on Cool Chair equipped with warming function

Recent air-conditioning systems aim to provide thermal comfort for an unspecified number of residents. However, office workers may perceive the feeling of comfort differently depending on their clothing, metabolic rate, and personal activity level. This may cause difficulties in maintaining an optimal thermal environment. To address this problem, personal air-conditioning has attracted attention, which is highly versatile and can reduce thermal discomfort and provide comfort to all office workers by enabling individual thermal control. Therefore, the authors focused on developing an office chair, the “Cool Chair”, as a chair-type personal air-conditioning system with a cooling function from 2003 to 2016. The authors then added a warming function for year-round operation, creating the “Cool Chair with Warming Function” in 2017. Subjective evaluation results are reported. These experiments using the new chair indicated that the warming function achieves steady state in 30 minutes and the equivalent temperature of the entire body increases by +2°C. In subject experiments, the warming and cooling functions were adjusted according to individual preferences, and the cooling function was used even during winter by some individuals. The authors also confirmed that the feeling of comfort by the subjects improved at both 19°C and 22°C.

Effects of population, urbanization, household size, and income on electric appliance adoption in the Chinese residential sector towards 2050

We present an analytical framework to project adoption of household electric appliances under a number of scenarios with different levels of population, urbanization, household size, and per-capita income. This framework enables us to estimate the saturation (i.e., number of a particular electric appliance per household) and the extent of adoption (total number of a particular electric appliance owned in each province), and to assess the impact of each driver. We focus on six types of appliances: personal computer, air conditioner, microwave oven, refrigerator, washing machine and television, and project their adoption during the 2015–2050 period. The projections are conducted for forty-five scenarios that combine five levels of population growth, three levels of per-capita gross domestic product (GDP) and income growth, and three levels of change in household size. We find that, among the six appliances investigated, ownership of personal computers and air conditioning equipment will grow the most, and that the current differences in appliance saturation among provinces and between urban and rural regions will almost disappear by 2050. However, most of the appliances will be owned in urban centers in Eastern China, where the majority of the population will be concentrated. Income growth, combined with urbanization and a reduction in household sizes, increases the total number of appliances, while a reduction in population decreases the total number of appliances. The results can be used as key inputs for long-term electricity system planning and to explore the potential effects of policies to support End-Use Energy Efficiency and Demand Side Response.

オフィスビルにおけるパーソナル温熱環境の最適化の追及 （第２報）パーソナル温熱環境制御システムの実大実験

オフィスビルにおけるパーソナル温熱環境の最適化の追及 （第２報）パーソナル温熱環境制御システムの実大実験

個別分散型エアコンを用いたパーソナル空調の検討 （その4） 気流性状及びPMV一定制御による省エネルギー性能の評価

個別分散型エアコンを用いたパーソナル空調の検討 （その4） 気流性状及びPMV一定制御による省エネルギー性能の評価

個別分散型エアコンを用いたパーソナル空調の検討 （その１４）気流切換え条件の検討および実吹出口を想定した人体への影響

個別分散型エアコンを用いたパーソナル空調の検討 （その１４）気流切換え条件の検討および実吹出口を想定した人体への影響

個別分散型エアコンを用いたパーソナル空調の検討 （その１３）局所気流が人体生理反応と温冷感に及ぼす影響

個別分散型エアコンを用いたパーソナル空調の検討 （その１３）局所気流が人体生理反応と温冷感に及ぼす影響

人間の熱的適応性を考慮したパーソナル空調システムに関する研究 : 第1報-従来型パーソナル空調システムの被験者実験による評価

人間の熱的適応性を考慮したパーソナル空調システムに関する研究 : 第1報-従来型パーソナル空調システムの被験者実験による評価

人間の熱的適応性を考慮したパーソナル空調システムに関する研究 : 第2報-パーソナル空調による活動変化に伴う熱的不快感緩和時間の検討

人間の熱的適応性を考慮したパーソナル空調システムに関する研究 : 第2報-パーソナル空調による活動変化に伴う熱的不快感緩和時間の検討

Study on the Personal Air-conditioning System Considering Human Thermal Adaptation : Part 3-Thermal sensitivity of each part of human body with Personal AC

Study on the Personal Air-conditioning System Considering Human Thermal Adaptation : Part 3-Thermal sensitivity of each part of human body with Personal AC

C-50 放射冷暖房を考慮したパーソナル空調方式に関する研究 : (第1報) 放射冷房とパーソナル吹出口の基礎特性

C-50 放射冷暖房を考慮したパーソナル空調方式に関する研究 : (第1報) 放射冷房とパーソナル吹出口の基礎特性

C-5 パーソナル空調機を用いた自然換気併用空調オフィスに関する研究 : (第14報)人体熱モデルによる椅子座位人体の位置変更に伴う温熱生理応答の比較

C-5 パーソナル空調機を用いた自然換気併用空調オフィスに関する研究 : (第14報)人体熱モデルによる椅子座位人体の位置変更に伴う温熱生理応答の比較

C-8 4床病室におけるパーソナル空調システムの実測評価

C-8 4床病室におけるパーソナル空調システムの実測評価

실험을 통한 이동형 냉방기의 실내 온도분포 특성의 검토

Abstract The purpose of this study is to analyze the indoor temperature distribution of a room controlled by a personaland portable cooler. As an energy saving strategy, the personal air-conditioning or task conditioning system was developedand installed in office buildings in the 90 s. Many research results regarding the personal air-conditioning (PAC) system were focused on thermal comfort, localized ventilation efficiency and energy savings. However, the conventional PACs wereonly developed for application in office buildings. In this study, as a type of PAC, a portable cooler was analyzed in termsof indoor temperature distribution changes with the passage of time. The measurement was performed in a bedroom in an apartment house. The results showed that indoor temperature was controlled at about 24 ℃ around the human body. However,the ambient zone up to 1.5 m away from the the human body stayed at about 27.5 ℃ . Key words Portable cooler(이동형 냉방기기), Personal cooling(개별냉방), Indoor thermal environment(온열 환경), Task area(작업영역), Field measurement(현장 실측)†Corresponding author, E-mail:

デシカント方式除湿器を用いた間接気化式冷却によるパーソナル空調システムの省エネルギーに関する検討

デシカント方式除湿器を用いた間接気化式冷却によるパーソナル空調システムの省エネルギーに関する検討

Study of a Micro Thermal Environment of a Personal Air-Conditioning

In a highly developed living, people are always looking for a comfortable indoor environment with minimum energy use. Regional air conditioning mechanism (RACM) can create a personal thermal comfort control in a workroom which can contribute to save air-conditioning energy. In this study, we analyze the airflow circulation cell of the RACM with varied inlet port opening and inlet port position dimensions using the computational fluid dynamics (CFD) technique. We created a RACM, two workstations, lightings, and a cabinet in a 3-dimensional room. The fluid was assumed to be Newtonian, unsteady, and incompressible. A Bossinesq approximation was determined in order to consider the buoyancy effect. We examined the effects of the inlet port opening and inlet port position on airflow circulation establishing process. Air temperatures along the various midline of the occupied zone were predicted and compared for a range of inlet port opening and inlet port position by using nondimensional form. We also showed the occupied zone temperature at various planes in the workroom. Results will indicate the suitable inlet port opening and inlet port position for maintaining individual satisfied occupants’ requirements and improving energy saving potential.