Enhanced effects of footwarmer by wearing sandals in winter office: A Swedish case study

2020 ◽  
pp. 1420326X2091397 ◽  
Author(s):  
Bin Yang ◽  
Zhe Li ◽  
Bin Zhou ◽  
Thomas Olofsson ◽  
Angui Li
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Heating Temperature ◽  
Whole Body ◽  
Thermal Stimulus ◽  
Body Parts ◽  
Heating Effects ◽  
Localized Heating ◽  
Cooling Devices ◽  
Local Thermal Comfort

Human-centred thermal environment conditioning can guarantee thermal comfort needs of human occupants in their micro-environments by using localized heating/cooling devices. Meanwhile, less intensified thermal conditioning of unoccupied surrounding environments can achieve heating/cooling energy efficiency. The concept was originated from task/ambient conditioning, which was developed for personal comfort systems. Most of the localized heating/cooling devices are workstation based or chair based. Task conditioning would become more closely to targets (human bodies) by using special clothing materials or thermoelectric elements. From thermal physiological viewpoints, thermal stimulus to thermally sensitive body parts may generate better results for not only local thermal comfort but also for whole body thermal comfort. Thermal stimulus to the extremities (feet) has demonstrated good thermal comfort effects. Scandinavians are accustomed to outdoor harsh environments and prefer wearing heavy shoes' outdoors in winter. They have the habit of changing heavy shoes to sandals when entering offices, which give the opportunity to enhance localized heating effects of footwarmers by reducing shoes’ thermal resistance. Climatic chamber tests with 32 Nordic subjects were performed under different indoor ambient heating temperatures with/without the aid of footwarmers. With footwarmers and sandals, indoor heating temperature at 16°C was acceptable, which achieved energy efficient thermal comfort.

scholarly journals Development of a Deep Neural Network Model for Estimating Joint Location of Occupant Indoor Activities for Providing Thermal Comfort

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 696
Author(s):  
Eun Ji Choi ◽  
Jin Woo Moon ◽  
Ji-hoon Han ◽  
Yongseok Yoo
Keyword(s):  
Neural Network ◽  
Thermal Comfort ◽  
Deep Neural Network ◽  
Mean Squared Error ◽  
Thermal Environment ◽  
The Body ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Body Parts ◽  
Joint Location

The type of occupant activities is a significantly important factor to determine indoor thermal comfort; thus, an accurate method to estimate occupant activity needs to be developed. The purpose of this study was to develop a deep neural network (DNN) model for estimating the joint location of diverse human activities, which will be used to provide a comfortable thermal environment. The DNN model was trained with images to estimate 14 joints of a person performing 10 common indoor activities. The DNN contained numerous shortcut connections for efficient training and had two stages of sequential and parallel layers for accurate joint localization. Estimation accuracy was quantified using the mean squared error (MSE) for the estimated joints and the percentage of correct parts (PCP) for the body parts. The results show that the joint MSEs for the head and neck were lowest, and the PCP was highest for the torso. The PCP for individual activities ranged from 0.71 to 0.92, while typing and standing in a relaxed manner were the activities with the highest PCP. Estimation accuracy was higher for relatively still activities and lower for activities involving wide-ranging arm or leg motion. This study thus highlights the potential for the accurate estimation of occupant indoor activities by proposing a novel DNN model. This approach holds significant promise for finding the actual type of occupant activities and for use in target indoor applications related to thermal comfort in buildings.

scholarly journals Interaction between Sound and Thermal Influences on Patient Comfort in the Hospitals of China’s Northern Heating Region

2019 ◽  
Vol 9 (24) ◽  
pp. 5551 ◽  
Author(s):  
Yue Wu ◽  
Qi Meng ◽  
Lei Li ◽  
Jingyi Mu
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Field Measurements ◽  
Negative Stimulus ◽  
Patient Comfort ◽  
Thermal Stimulus ◽  
Acoustic Environment ◽  
Heating Region ◽  
Increased Risk ◽  
Wide Range

Previous studies have found that hospitals are often inadequately ventilated in the heating region of China, which causes an increased risk of negative impacts on patients. The complex interaction between thermal comfort and acoustics presents considerable challenges for designers. There is a wide range of literature covering the area of the interaction between the sound–thermal, sound–odor, and acoustic–visual influences, but a focused research on the sound –thermal influence on comfort in hospitals has not been published yet. This paper describes a series of field measurements and subjective evaluations that investigate the thermal comfort and acoustic performance of eighteen hospitals in China. The results showed that the thermal comfort in the monitored wards was mostly acceptable, but the temperatures tended to be much higher and the humidity much lower, in practice than they were designed to be in the heating season. The most significant conclusion is that a positive thermal stimulus can create a comfortable thermal environment, which can improve patients’ evaluation of the acoustics, while a negative stimulus has the opposite effect. A comfortable acoustic environment also caused patients to positively evaluate thermal comfort. Moreover, the relationship between thermal and sound effects in the overall evaluation showed that they are almost equal.

scholarly journals Thermal Comfort Characteristics of Knitted Fabrics for Abaya

2012 ◽  
Vol 627 ◽  
pp. 164-169 ◽  
Author(s):  
Salwa Tashkandi ◽  
Li Jing Wang ◽  
Sinnappoo Kanesalingam ◽  
Amit Jadhav
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Whole Body ◽  
Transmission Characteristics ◽  
Knitted Fabrics ◽  
Hot Environment ◽  
Middle East Countries ◽  
Fabric Weight ◽  
Outer Garment ◽  
Fabric Material

Fabric material plays an important role in the thermal comfort of Abaya because it is the outer garment of Muslim women. Abaya is black in colour and covers the whole body except the hands, feet and face. It is mandatory to wear Abaya in the Saudi Arabia and certain parts of Middle East countries irrespective of the outside environmental temperature which could be up to 45°C. Therefore, the thermal transmission characteristics of the abaya are extremely important as human body responds to the external thermal environment through clothing. In a hot environment, it is extremely uncomfortable to wear several layers of clothing under the Abaya. Hence it is essential to enhance the thermal comfort of fabrics used for Abaya. This study investigated five selected knitted fabrics that could be used as Abaya fabrics for thermal resistance, air permeability, thermal comfort and vapour resistance. The results indicated that the fabrics with different knit structures, fibre composition and fabric weight have greater influence on thermal comfort performance.

Investigation and comparison on thermal comfort and energy consumption of four personalized seat heating systems based on heated floor panels

2020 ◽  
pp. 1420326X2093914
Author(s):  
Guoqing Yu ◽  
Zhaoji Gu ◽  
Zhenye Yan ◽  
Hengtao Chen
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Yangtze River Basin ◽  
High Energy ◽  
Body Parts ◽  
Lower Body ◽  
Heating Systems ◽  
Heated Floor

The climate of Yangtze River Basin in China is cold and humid in winter. Conventional air-conditioning systems may cause high energy consumption and uncomfortable microclimatic conditions especially for lower body of indoor occupants. This study investigated four personalized seat heating systems, in a typical office room in Shanghai during winter, based on heated floor panels including heated floor panels + ordinary chair (HF-OC), heated floor panels + insulated chair (HF-IC), heated floor panels +insulated chair and leg box (HF-IC-LB) and overall personalized heating (OPH). The surface temperature of walls and heated floor panels, and the indoor air temperature at different positions were recorded with thermocouples. The hourly energy consumptions of the proposed personalized seat heating systems were measured and compared with a conventional split type air conditioner. Questionnaires of thermal sensation and comfort were carried out among 10 university students. Compared with HF-OC, HF-IC could improve the thermal comfort to a certain extent, while HF-IC-LB provided the optimal thermal micro-environment for the lower body other than other body parts. The OPH systems were proven effective to provide satisfactory thermal environment for all body parts at lower indoor temperature (12–16°C) with much less energy consumption than room air conditioners.

Exploring the effect of mattress cushion materials on human–mattress interface temperatures, pre-sleep thermal state and sleep quality

2020 ◽  
pp. 1420326X2090337
Author(s):  
Xiaxia Li ◽  
Bo Zhou ◽  
Liming Shen ◽  
Zhihui Wu
Keyword(s):  
Sleep Quality ◽  
Thermal State ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Cold Climate ◽  
The Body ◽  
Whole Body ◽  
Interface Temperature ◽  
Body Parts ◽  
Human Thermal Comfort

A comfortable mattress can create a good sleep environment, but the thermal behaviour of the interaction between the human body and mattress materials is still not well understood. The effect of mattress materials on human–mattress interface temperature and human thermal state was evaluated by subjective questionnaire and measurements to detemine the human–mattress interface temperatures of the whole body and various locations of the body (WTH-M and ETH-M). The woollen fabric and polymeric foam of mattresses were evaluated as optimal cushion materials; these were indicated by measurements at 15.5 and 20°C, due to the higher WTH-M and ETH-M. Moreover, the interface temperatures measured at the back, buttock and thigh were higher with most materials than at other parts of the body, indicating a lower temperature response at the body extremities due to the body–mattress interface. Under the cold climate, people would prefer warm thermal sensation rather than the neutral thermal feeling. There should be more consideration on the thermal insulation of the extremities such as the feet. The human thermal response was not only affected by mattress materials, but also by body parts and indoor air temperatures. These findings are important to understand the heat transfer and human thermal comfort requirements, providing a comfortable thermal environment to ensure sleep quality.

The effects of firefighting boots and personal protective equipment load on foot thermal comfort

2021 ◽  
pp. 004051752110265
Author(s):  
Miao Tian ◽  
Xianghui Zhang ◽  
Xumei Tang
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Personal Protective Equipment ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Whole Body ◽  
Protective Equipment ◽  
Human Foot ◽  
Physiological Variables ◽  
Psychological Scales

Maintaining foot comfort is important as it influences the overall comfort of the human body. Shoe microclimate and foot skin temperature have been suggested to contribute to the thermal sensation of the foot. Considering the thermal environment and personal protective equipment (PPE) used for structural and proximity firefighting, climatic chamber tests with 13 male participants were conducted during standing and walking. Four test conditions – unloaded with training shoes, loaded with training shoes, unloaded with firefighting boots, and loaded with firefighting boots – were designed to investigate the effects of firefighting boots and PPE load on the thermal comfort of the human foot. Physiological variables of in-shoe and foot skin temperature at the whole and local regions of the foot were measured and subjective responses were gathered using psychological scales. The results showed that wearing firefighting boots may elevate the thermal sensation of wearers. The PPE load increased the in-shoe and foot skin temperature as well as subjective ratings. Subjective sensations of the foot were strongly correlated with in-shoe and skin temperature in the plantar regions. Correlation analysis of thermal sensation at the whole and local foot regions indicated that the sensation at the forefoot was closest to the whole foot, followed by the midfoot and heel. The findings address the relationship of physiological and subjective variables as well as the thermal sensation of whole and local foot regions, which can be considered for footwear design and thermal comfort prediction of the foot and whole body.

scholarly journals Effect of thermochromic coatings on the indoor thermal behavior of a case study building

2021 ◽  
Vol 238 ◽  
pp. 06003
Author(s):  
Claudia Fabiani ◽  
Anna Laura Pisello
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Positive Impact ◽  
Central Italy ◽  
Research Work ◽  
Research Field ◽  
Building Envelope ◽  
Local Boundary ◽  
Local Thermal Comfort

Passive systems and solutions aimed at improving local thermal comfort conditions represent a cutting-edge research field in building applications. However, only a few investigations were performed by taking into account the local distribution and spatial variability of the airflow generated by the application of both traditional and innovative passive strategies. The present research work is aimed at bridging such gap by modelling the indoor thermal environment of a case study prototype building, i.e. test-room, situated in central Italy, by taking into account the indoor heat transfer phenomena. In particular, a CFD model of the building is elaborated and used to predict the indoor thermal effect of an adaptive thermochromic envelope, compared to more traditional solutions. The simulation results are post-processed in terms of (i) indoor temperature and (ii) indoor airflows. The main findings confirm a non-negligible and positive impact of the thermochromic building envelope on the local indoor thermal comfort conditions in both summer and winter conditions, due to its capability of selectively tailor the absorption of heat gains and a function of the local boundary conditions.

scholarly journals Assessment of Thermal Environment in a Kitchen with a New Ventilation System

2019 ◽  
Vol 111 ◽  
pp. 02034 ◽  
Author(s):  
Sumei Liu ◽  
Xiaojie Zhou ◽  
Xuan Liu ◽  
Xiaorui Lin ◽  
Ke Qing ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Great Influence ◽  
Comfort Level ◽  
Whole Body ◽  
Body Parts

Chinese kitchen environment is usually hot and humid in summer and cold in winter, while housewife spends considerable time there. This investigation developed a new ventilation system for Chinese kitchens to improve thermal comfort level. To assess the thermal performance of the ventilation system, 32 cooks were asked to prepare the same dishes in the kitchen with or without the system in summer in Changsha, China. The assessment was carried out by subjective questionnaire survey on thermal sensation vote (TSV) and objective on-site measurements of the indoor air temperature and cook’s skin temperature. The indoor air temperature was measured at different locations in the kitchen. The skin temperature was measured at 18 body parts of the cooks. The results show that the thermal environment in the kitchen was non-uniform and local thermal sensation had a great influence on the whole body sensation. Without the new ventilation system, the cooks complained that the hottest parts were thorax, head and face areas. Reasonably good correlation existed between the cooks’ skin temperatures and their thermal sensation votes. The increase of cooks’ skin temperature with the ventilation system was lower than that without the ventilation system. TSV was improved with the new ventilation system.

scholarly journals An Exploration of Relationships among Thermal Insulation, Area Factor and Air Gap of Male Chinese Ethnic Costumes

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1302
Author(s):  
Ying Ke ◽  
Faming Wang
Keyword(s):  
Thermal Insulation ◽  
Minority Groups ◽  
Body Part ◽  
Air Gap ◽  
Whole Body ◽  
Gap Size ◽  
Body Parts ◽  
Air Volume ◽  
Local Thermal Insulation ◽  
Local Thermal Comfort

The present study investigated total and local thermal insulations of 39 sets of male Chinese ethnic costumes. Total and local clothing area factor, air gap size and air volume were determined by a 3D body scanner. Relationships between thermal insulation and air gap for the whole body, as well as local body parts, were explored. Correlations of both the total and local clothing area factor with the intrinsic insulation were also developed. Results demonstrated that the clothing total thermal insulation first increased with the increasing air gap size/air volume, followed by a decrease when the air gap size/air volume exceeded 37.8 mm/55.8 dm3. Similarly, it was also found that parabolic relationships widely existed between the local thermal insulation and local air gap at each body part. Our research findings provide a comprehensive database for predicting both global and local thermal comfort of male Chinese minority groups.

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