Evaluation of Human Thermal Comfort Using Near-Infrared Spectroscopy

2014 ◽  
Author(s):  
Keiichi Watanuki ◽  
Lei Hou ◽  
Yuuki Kondou
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Brain Activation ◽  
Indoor Temperature ◽  
Prefrontal Area ◽  
Human Thermal Comfort ◽  
Conditioning Control

Air-conditioning equipment is used in various places such as houses, office buildings, and public facilities and is indispensable in modern-day life. Therefore, the energy consumption of air-conditioning equipment accounts for a large percentage of the total energy consumption in the average household. Specifically, it accounts for 26% of the annual energy consumption in ordinary homes and 27% in industry, according to the Annual Energy Report for Japan, which was presented by the Ministry of the Economy, Trade, and Industry, and the Agency for Natural Resources and Energy in 2010. Therefore, it is desirable to reduce energy consumption by reducing the air-conditioning load. The Ministry of the Environment recommends a constant preset temperature of 28°C in summer to decrease energy consumption. However, many people feel uncomfortable in such a thermal environment. Thus, an air-conditioning control to simultaneously suppress energy consumption and maintain human thermal comfort is desired. To develop such a control, an index to accurately evaluate human thermal comfort is needed. When a person feels comfortable or uncomfortable, their prefrontal area, which is involved in thinking and the feeling of emotions, is activated. It is presumed that the measurement of the brain activation reaction of a person will reveal whether the person feels comfortable or uncomfortable in the thermal environment. The evaluation of thermal comfort by means of brain activation reactions will allow one to develop the optimum air-conditioning control to maintain human thermal comfort. This paper proposes a method to evaluate thermal comfort via brain signals and ultimately aims to develop an air-conditioning control system utilizing this evaluation method. This paper will describe the measurement procedure of brain activation reactions to indoor-temperature change by using near-infrared spectroscopy and the relationship between thermal comfort and brain activation reaction. This study also investigated the changes in oxyHb levels together with indoor-temperature changes, measured with the NIRS. We measured the changes in the oxyHb levels of the prefrontal area when the temperature increased and decreased. As a result, the oxyHb level in the prefrontal area correlated with the indoor-temperature change, the PMV, and the subjects’ declaration of thermal sensation. Conversely, the change in the oxyHb level with the inclusion of wind and a constant indoor temperature significantly differed with that with a varying indoor temperature. Furthermore, the oxyHb change correlated with the PMV and the subject’s declaration of thermal sensation. Therefore, the measured oxyHb change may represent the thermal comfort of a person.

Analysis of the influence of cooling jets on the wind and thermal environment in football stadiums in hot climates

2019 ◽  
Vol 41 (5) ◽  
pp. 561-585 ◽  
Author(s):  
Fangliang Zhong ◽  
John K Calautit ◽  
Ben R Hughes
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Optimized Design ◽  
Outdoor Temperature ◽  
World Cup ◽  
Wind Environment ◽  
The Spectator

After winning the bid of the FIFA’s World Cup 2022, Qatar is facing the greatest challenges in terms of minimizing substantial energy consumptions for air-conditioning of stadiums and maintaining aero-thermal comfort for both players and spectators inside stadiums. This paper presents the results of temperature distributions and wind environment of the original stadium under the hot-humid climate and improvements on them for optimized scenarios of cooling jets. A combined computational fluid dynamics and building energy simulation approach was used to analyse the cooling performance and energy consumption per match of cooling air jets for 10 scenarios with different supply velocities, supply temperatures and locations of jets. The optimal scenario is to employ vertical jets above the upper tiers at supply temperature of 20°C and velocities of 2–12 m/s, integrated with horizontal jets of the same temperature at the lower tiers with 4 m/s and around the pitch with 7 m/s. This scenario can maintain the spectator tiers at an average temperature of 22°C and reduce the maximum predicted percentage of dissatisfied of thermal comfort from the original 100% to 63% for the pitch and 19% for the tiers, respectively. In terms of the energy consumption for the air-conditioning system per match, compared with one of the 2010 South Africa World Cup stadiums Royal Bafokeng stadium which consumed approximately 22.8 MWh energy for air-conditioning in winter (highest outdoor temperature 24.4°C), the maximum energy consumption of the optimal scenario in November (highest outdoor temperature 34.2°C) can reach 108 MWh. In addition, the spectator zones with scenario 8 have the potential to be resilient to the seasonal change of outdoor temperature if slight modifications of the supply velocities and precise temperature control on the spectator zones are applied. Moreover, the configurations presented in this paper can be used as a foundation of jets arrangement for future stadium retrofits in the hot climates. Practical application: This study assesses the aero-thermal conditions of a case study stadium under the hot climate of Qatar and explores the potential of applying cooling jets with different supply velocities, supply temperatures and their locations on the enhancement of both thermal and wind environment of spectator tiers and pitch. The assessment of the original stadium indicates that the ascending curved roof structure impedes the fresh air entering into the stadium and results in an asymmetric temperature distribution on the spectator tiers. The optimized design suggests a combination of vertical jets under the roof and both three arrays of horizontal jets at lower tiers and around pitch for future stadium optimizations in hot climates. It also recommends enhancing the thermal conditions on the pitch by optimizing the velocity of horizontal jets around the pitch. Moreover, the future design of the exact stadiums to be resilient to the seasonal changing outdoor temperature can be implemented based on scenario 8.

scholarly journals Thermal Comfort Assessment at Parcel and Logistic Industry: A Field Study in Malaysia

2011 ◽  
Vol 72 (3) ◽  
Author(s):  
Ahmad Rasdan Ismail ◽  
Norfadzilah Jusoh ◽  
Mohd nizam ab. rahman Ab. rahman ◽  
Rozli Zulkifli ◽  
Kumaran Kardigama
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Time Series Data ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Series Data ◽  
Energy Research ◽  
Iso Standard ◽  
Environment Factors ◽  
Solar Energy Research Institute

This paper presents the workers thermal sensation votes and perception of the thermal environment in air conditioning at one of the workspace in Malaysian parcel and logistic industry. The environment factors examined was the relative humidity (%), wind speed (m/s), air temperature (C) and CO2 (ppm) of the surrounding workstation area. These factors were measured using custom integrated thermal comfort apparatus namely as Thermal Comfort Equipment developed by Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, which is capable of measuring various environmental factors. The time series data of fluctuating level of environment factors were plotted to identify the significant changes and patterns among the factors. Then the thermal comfort of the workers was assessed by using ISO Standard 7730 and thermal sensation scale by using Predicted Mean Vote (PMV). Further Predicted Percentage Dissatisfied (PPD) is used to estimate the thermal comfort satisfaction of the occupant. Finally the PMV and PPD were plotted to present the thermal comfort scenario of workers involved in related workspace. The results revealed that the thermal comfort at the particular workplace was warming followed by thermal sensation and likely to be dissatisfied by dominant of occupants. The results also indicated that the CO2and index of clothing (clo) dominated the parameters of comfort to the occupants.

scholarly journals Impact of ventilation system type on indoor thermal environment and human thermal comfort in a ceiling cooling room

2021 ◽  
pp. 277-277
Author(s):  
Xiaozhou Wu ◽  
Genglin Liu ◽  
Jie Gao ◽  
Shuang Wu
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Physical Parameters ◽  
Curtain Wall ◽  
Indoor Thermal Environment ◽  
Human Thermal Comfort ◽  
System Type

A ceiling cooling (CC) system integrated with a mechanical ventilation system is an advanced HVAC system for the modern office building with glass curtain wall. In this paper, considering the influence of heat transfer of external envelope, the indoor thermal environment and human thermal comfort were objectively measured and subjectively evaluated in a ceiling cooling room with mixing ventilation (MV) or underfloor air distribution (UFAD). Indoor physical parameters and human skin temperatures were measured as the chilled ceiling surface temperature and supply air temperature were 17.1?C-17.6?C and 22.2?C - 22.6?C. Simultaneously, 16 subjects (8 males and 8 females) were selected to subjectively evaluate the thermal environment. The results showed that the difference between mean radiant temperature and air temperature in the occupied zone was 0.8?C with CC+MV and 1.2?C with CC+UFAD, and the indoor air velocity was 0.17m/s with CC+MV and 0.13m/s with CC+UFAD. In addition, the calculated and measured thermal sensation votes with CC+MV were all slightly less than those with CC+UFAD. Therefore, ventilation system type had a slight impact on the indoor thermal environment and human thermal comfort in the ceiling cooling room.

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.

scholarly journals Does a neutral thermal sensation determine thermal comfort?

2018 ◽  
Vol 39 (2) ◽  
pp. 183-195 ◽  
Author(s):  
Sally Shahzad ◽  
John Brennan ◽  
Dimitris Theodossopoulos ◽  
John K Calautit ◽  
Ben R Hughes
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Building Design ◽  
Thermal Preference ◽  
Practical Application ◽  
Comfort Zone ◽  
Indoor Thermal Environment ◽  
Human Thermal Comfort ◽  
Comfort Condition

The neutral thermal sensation (neither cold, nor hot) is widely used through the application of the ASHRAE seven-point thermal sensation scale to assess thermal comfort. This study investigated the application of the neutral thermal sensation and it questions the reliability of any study that solely relies on neutral thermal sensation. Although thermal-neutrality has already been questioned, still most thermal comfort studies only use this measure to assess thermal comfort of the occupants. In this study, the connection of the occupant’s thermal comfort with thermal-neutrality was investigated in two separate contexts of Norwegian and British offices. Overall, the thermal environment of four office buildings was evaluated and 313 responses (three times a day) to thermal sensation, thermal preference, comfort, and satisfaction were recorded. The results suggested that 36% of the occupants did not want to feel neutral and they considered thermal sensations other than neutral as their comfort condition. Also, in order to feel comfortable, respondents reported wanting to feel different thermal sensations at different times of the day suggesting that occupant desire for thermal comfort conditions may not be as steady as anticipated. This study recommends that other measures are required to assess human thermal comfort, such as thermal preference. Practical application: This study questions the application of neutral thermal sensation as the measure of thermal comfort. The findings indicate that occupant may consider other sensations than neutral as comfortable. This finding directly questions the standard comfort zone (e.g. ASHRAE Standard 55) as well as the optimum temperature, as many occupants required different thermal sensations at different times of the day to feel comfortable. These findings suggest that a steady indoor thermal environment does not guarantee thermal comfort and variations in the room temperature, which can be controlled by the occupant, need to be considered as part of the building design.

Field Test for Heat and Humidity Environment and Analysis of Air-Conditioning System Consumption

2012 ◽  
Vol 610-613 ◽  
pp. 2875-2878
Author(s):  
Hui Xing Li ◽  
Wei Xiao ◽  
Geng Geng ◽  
Bei Ni Li ◽  
Wei Wang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Building Energy ◽  
Future Research ◽  
Main Body ◽  
Indoor Temperature ◽  
Air Conditioning System ◽  
Air Conditioning Systems ◽  
Humidity Environment

Museum has its particularity in public buildings and high research value for its thermal and humidity environment and building energy efficiency status. According to a investigation of air-conditioning systems and a test of indoor heat and humidity parameters in summer and winter for a museum in Shenyang, this article analysis its thermal environment and air-conditioning energy consumption status, draw the winter and summer indoor temperature and humidity and air-conditioning energy consumption chart, research the indoor temperature change rules and the energy consumption status of air-conditioning system in winter and summer. The results show that as air-conditioning energy consumption accounted for the main body of museum’s total building energy consumption, more energy-efficient technologies can be used to reduce the energy consumption of air-conditioning systems. And how to control the thermal environment of different types of collections in this museum, and take a consideration of energy saving, are focues of future research.

Effect of Wind Velocity on Clothing Thermal Resistance and Indoor Comfortable Temperature Design

2011 ◽  
Vol 332-334 ◽  
pp. 1600-1603
Author(s):  
Sha Li ◽  
Rui Wang ◽  
Xiao Ming Qian ◽  
Zi Jun Zhao
Keyword(s):  
Energy Consumption ◽  
Thermal Resistance ◽  
Wind Velocity ◽  
Indoor Air ◽  
Air Conditioning ◽  
Thermal Sensation ◽  
Air Velocity ◽  
Indoor Temperature ◽  
Air Conditioning System ◽  
Current Specification

In this paper, it uses a manikin to test effect of wind velocity on the surface of clothing thermal resistance, and concludes that with the increase of wind velocity, the heat resistance of the clothing decrease rapidly. A seven-point thermal sensation scale was used to evaluate thermal sensation in Tianjin area, the result shows that the neutral temperature is 27.2 °C when the wind velocity is 0.82 m/s . Above 3.2°C is higher than the current specification recommended indoor temperature 24°C. It shows an appropriate increase indoor air velocity can improve the building comfortable temperature. Saving energy 29.7％一41.6％.So provides an effective way reducing the energy consumption of the air conditioning system.

scholarly journals Experimental Study and Analysis of Thermal Comfort in a University Campus Building in Tropical Climate

2020 ◽  
Vol 12 (21) ◽  
pp. 8886
Author(s):  
Milen Balbis-Morejón ◽  
Javier M. Rey-Hernández ◽  
Carlos Amaris-Castilla ◽  
Eloy Velasco-Gómez ◽  
Julio F. San José-Alonso ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Sensitivity ◽  
Tropical Climate ◽  
Air Conditioning System ◽  
Humidity Measurements ◽  
Air Conditioning Systems ◽  
Thermal Preferences

This study presents the evaluation of the performance and acceptability of thermal comfort by students in the classrooms of a university building with minisplit-type air-conditioning systems, in a tropical climate. To carry out the study, temperature and humidity measurements were recorded, both outside and inside the selected classrooms, while the students were asked to complete thermal surveys on site. The survey model is based on the template proposed by Fanger and it was applied to a total number of 584 students. In each classroom, the Predicted Mean Vote (PMV) and the Predicted Percentage Dissatisfied (PPD) were estimated according to Fanger’s methodology, as well as the Thermal Sensation Vote (TSV) and the Actual Percentage Dissatisfied (APD), which were obtained from the measurements and the surveys. The results of this study showed that the PMV values, although they may vary with the insulation of the clothing, do not affect the TSV. Furthermore, comparing PMV vs. TSV scores, a 2 °C to 3 °C difference in operating temperature was found, whereby the thermal sensitivity for TSV was colder, so it could be assumed that the PMV model overestimates the thermal sensitivity of students in low-temperature conditions. In addition, an acceptability by 90% with thermal preferences between 23 °C and 24 °C were also found. These results indicate that it is possible to increase the temperature set point in minisplit-type air-conditioning system from 4 °C to 7 °C with respect to the currently set temperatures, without affecting the acceptability of the thermal environment to the students in the building.

A Pilot Test to Analyse the Differences of Pedestrian Thermal Comfort Between Locals and Internationals in Malacca Heritage Site

2020 ◽  
Vol 11 (2) ◽  
pp. 326-341
Author(s):  
Golnoosh Manteghi ◽  
Tasneem Mostofa ◽  
Hasanuddin Bin Lamit
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Outdoor Thermal Comfort ◽  
Pilot Test ◽  
Physiological Equivalent Temperature ◽  
Demographic Groups ◽  
Human Thermal Comfort ◽  
Heritage Site ◽  
Outdoor Spaces

The present study aims to establish a correlation between the physiological equivalent temperature (PET) and subjective thermal sensation in the Tropics, assessing their impact on local as well as international pedestrians. The pilot test was conducted in six scenarios in the Malacca region of Malaysia. The RayMan model calculated the PET, which is further used to synthetically evaluate the thermal environment for six scenarios, each with a different river width and pavement material. The independent t-test and regression analysis determined the correlation between human thermal comfort acceptability and the thermal environment indices of outdoor spaces. Most of the outdoor thermal comfort assessments have been carried out focusing on local urban residents, while the same assessments on tourists are limited. This research provides necessary insight into the perception of outdoor microclimatic conditions in the Malacca heritage area and also identifies the perception on a few important psychological factors of these two demographic groups. An awareness of such issues would be fruitful for architects, planners and urban designers engaged in the process of designing and planning tourist destinations.

scholarly journals Energy-Saving Potential of Extending Temperature Set-Points in a VRF Air-Conditioned Building

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2160 ◽  
Author(s):  
Joowook Kim ◽  
Doosam Song ◽  
Suyeon Kim ◽  
Sohyun Park ◽  
Youngjin Choi ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Control Strategies ◽  
Hvac Systems ◽  
Set Point ◽  
Energy Saving Potential ◽  
Human Thermal Comfort

Building energy savings and occupant thermal comfort are the main issues in building technology. As such, the development of energy-efficient heating, ventilation, and air-conditioning (HVAC) systems and the control strategies of HVAC systems are emerging as important topics in the HVAC industry. Variable refrigerant flow (VRF) systems have efficient energy performance, so the use of VRF systems in buildings is increasing. However, most studies on VRF systems focus on improving mechanical efficiency, with few studies on energy-efficient control while satisfying the thermal comfort of occupants. The goal is to estimate the energy-saving potential of adjusting the temperature set-points and dead-band (range) in VRF air-conditioned building. To do so, we analyzed the influence of control strategies of a VRF system on human thermal comfort and energy consumption using a simulation method. The results showed that energy consumption can be reduced by 25.4% for predicted mean vote (PMV)-based control and 27.0% for the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) comfort range control compared with the typical set-point temperature control of a VRF system. The indoor thermal environments of the analyzed control strategies are controlled in the thermal comfort range, which is based on a PMV at ±0.5. Compared with the typical set-point control, PMV and ASHRAE comfort range-based control reduced the operation time of the compressor in the VRF system.

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