scholarly journals The role of clothing in thermal comfort: how people dress in a temperate and humid climate in Brazil

2017 ◽  
Vol 17 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Renata De Vecchi ◽  
Roberto Lamberts ◽  
Christhina Maria Candido
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
International Standards ◽  
Humid Climate ◽  
Great Opportunity ◽  
Input Variables ◽  
Air Speed ◽  
And Gender ◽  
Save Energy

Abstract Thermal insulation from clothing is one of the most important input variables used to predict the thermal comfort of a building's occupants. This paper investigates the clothing pattern in buildings with different configurations located in a temperate and humid climate in Brazil. Occupants of two kinds of buildings (three offices and two university classrooms) assessed their thermal environment through 'right-here-right-now' questionnaires, while at the same time indoor climatic measurements were carried out in situ (air temperature and radiant temperature, air speed and humidity). A total of 5,036 votes from 1,161 occupants were collected. Results suggest that the clothing values adopted by occupants inside buildings were influenced by: 1) climate and seasons of the year; 2) different configurations and indoor thermal conditions; and 3) occupants' age and gender. Significant intergenerational and gender differences were found, which might be explained by differences in metabolic rates and fashion. The results also indicate that there is a great opportunity to exceed the clothing interval of the thermal comfort zones proposed by international standards such as ASHRAE 55 (2013) - 0.5 to 1.0 clo - and thereby save energy from cooling and heating systems, without compromising the occupants' indoor thermal comfort.

scholarly journals Investigation of Indoor Thermal Environments in a Two-Story Corner Terrace House in Malaysia

2019 ◽  
Author(s):  
Ng Wai Tuck ◽  
Sheikh Ahmad Zaki ◽  
Aya Hagishima ◽  
Hom Bahadur Rijal ◽  
Mohd Azuan Zakaria ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Assisted Ventilation ◽  
International Standards ◽  
Actual Condition ◽  
Air Conditioner ◽  
Humid Climate ◽  
Ground Floor ◽  
Hot Humid Climate

An effective passive cooling strategy is essential for reducing energy consumption in a residential building without ignoring thermal comfort. Therefore, a field measurement on the thermal performance of a corner terrace house in Kuala Lumpur was conducted to reveal the effectiveness of free running (FR) with four different approaches – no ventilation, full ventilation, day ventilation, and night ventilation. The measurement was done for all bedrooms and family area on the first floor. Also, mixed mode (MM) consisting of natural ventilation, mechanical ventilation with ceiling fan, and cooling with an air-conditioner that represents the actual condition of this house was also measured at living and dining area on the ground floor for comparison. The results reveal that FR from all approaches recorded a mean indoor air temperature of approximately 31 ∘C. The actual thermal condition of the house with MM on the ground floor was recorded at 30 ∘C, 1 ∘C lower than FR approach on the first floor. When compared with relevant international standards on predicting indoor comfort temperature based on outdoor temperature, FR was approximately 5 ∘C higher than predicted temperature based on American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55 (2017), 3.4 ∘C higher than European Standard EN15251 and 1.5 ∘C higher than adaptive thermal comfort equation (ACE) for hot-humid climate. In comparison, MM performed better and was closer to relevant international standards, especially ACE for the hot-humid climate. As a conclusion, FR is not suitable for a hot-humid climate such as Malaysia to achieve a comfortable indoor thermal environment without any assisted ventilation use in MM.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

Some evidence of a time-varying thermal perception

2021 ◽  
pp. 1420326X2110345
Author(s):  
Marika Vellei ◽  
William O’Brien ◽  
Simon Martinez ◽  
Jérôme Le Dréau
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Time Of Day ◽  
Time Varying ◽  
Thermal Perception ◽  
Indoor Thermal Environment ◽  
Human Circadian Rhythm ◽  
Comfort Criteria

Recent research suggests that a time-varying indoor thermal environment can lead to energy savings and contribute to boost buildings' energy flexibility. However, thermal comfort standardization has so far considered thermal comfort criteria as constant throughout the day. In general, very little attention has been given to the ‘ time of day' variable in the context of thermal comfort research. In this paper, we show some evidence of a time-varying thermal perception by using: (1) data from about 10,000 connected Canadian thermostats made available as part of the ‘ Donate Your Data' dataset and (2) about 22,000 samples of complete (objective + ‘ right-here-right-now' subjective) thermal comfort field data from the ASHRAE I and SCATs datasets. We observe that occupants prefer colder thermal conditions at 14:00 and progressively warmer ones in the rest of the day, indistinctively in the morning and evening. Neutral temperature differences between 08:00 and 14:00 and 14:00 and 20:00 are estimated to be of the order of 2°C. We hypothesize that the human circadian rhythm is the cause of this difference. Nevertheless, the results of this study are only based on observational data. Thermal comfort experiments in controlled environmental chambers are required to confirm these findings and to better elucidate the effects of light and circadian timing and their interaction on thermal perception.

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.

A Review of the Impact of Vegetation in Solar Control towards Enhanced Thermal Comfort and Energy Performance in Buildings

2019 ◽  
Vol 887 ◽  
pp. 428-434
Author(s):  
Dorcas A. Ayeni ◽  
Olaniyi O. Aluko ◽  
Morisade O. Adegbie
Keyword(s):  
Thermal Comfort ◽  
Adaptive Capacity ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Building Design ◽  
Energy Performance ◽  
Tropical Region ◽  
Indoor Climate ◽  
Solar Control ◽  
The Impact

Man requires a thermal environment that is within the range of his adaptive capacity and if this fluctuates outside the normal, a reaction is required beyond its adaptive capacity which results to health challenges. Therefore, the aim of building design in the tropical region is to minimize the heat gain indoors and enhance evaporative cooling of the occupants of the space so as to achieve thermal comfort. In most cases, the passive technologies are not adequate in moderating indoor climate for human comfort thereby relying on active energy technique to provide the needed comfort for the building users. The need for the use of vegetation as a panacea for achieving comfortable indoor thermal conditions in housing is recognised by architects globally. However, the practice by architects in Nigeria is still at the lower ebb. The thrust of this paper therefore is to examine the impact of vegetation in solar control reducing thermal discomfort in housing thereby enhancing the energy performance of the buildings. Using secondary data, the paper identifies the benefits of vegetation in and around buildings to include improvement of indoor air quality through the aesthetics quality of the environment and concludes that vegetation in and around building will in no small measure contributes to saving energy consumption.

scholarly journals ANALISIS PENGARUH BENTUK SERAMBI MASJID TERHADAP KENYAMANAN TERMAL ADAPTIF

2020 ◽  
Vol 4 (3) ◽  
pp. 261
Author(s):  
Abdul Qodir ◽  
Erni Setyowati ◽  
Suryono Suryono
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Temperature Range ◽  
Adaptive Thermal Comfort ◽  
Environment Variables ◽  
Average Condition ◽  
Radiant Temperature ◽  
Thermal Preferences ◽  
Neutral Conditions

This study examines the effect of the porch on the adaptive thermal comfort of mosques by taking 2 mosques that have different porch shapes with the specific purpose of obtaining data on the neutrality, acceptability and preferences of the mosque respondents' thermal conditions in the framework of developing adaptive thermal comfort standards for Indonesia. Measurement of physical environment variables is done by taking data on temperature, humidity, air velocity, and mean radiant temperature (MRT) at 2 mosques and at the same time the impression and thermal preference questionnaire data are taken, examination of clothing types and activities, and list of thermal environment controls to 40 respondents in each mosque. Data of thermal neutrality and thermal preferences were analyzed by regression analysis using SPSS 19 software, while thermal acceptance was analyzed based on the results of the questionnaire answers. The analysis showed that the neutrality value at Ulul Albab mosque was Tdb = 28.47 OC, ET * = 30.11 OC, SET * = 23.11 OC, TSENS = 1.17, DISC = -1.06, and PMV = -0.65, this data shows that the neutral condition desired by respondents is slightly below the average condition, while the neutrality in Nurul Ilmi mosque at Tdb = 30.27 OC, ET * = 31.65 OC, SET * = 29.05 OC, TSENS = 1.03, DISC = 1.68, and PMV = 1.22, this data also shows that the neutral conditions desired by respondents are slightly below average conditions. While the preference value at Ulul Albab mosque is Tdb = 22.25 OC, ET * = 28.62 OC, SET * = 24.24 OC, TSENS = 0.23, DISC = 0.23, and PMV = -0.60 and preference conditions at Nurul Ilmi mosque at Tdb = 29.11 OC, ET * = 31.17 OC, SET * = 28.50 OC, TSENS = 1.04, DISC = 1.45, and PMV = 1.03. As many as 92% of respondents in the Ulul Albab mosque can accept local thermal conditions in the temperature range of 27oC - 31oC. While 90% of respondents in the Nurul Ilmi mosque can accept local thermal conditions in the temperature range of 27oC-32oC. The results of the neutrality, acceptance and preference analysis show that the Ulul Albab mosque is better than the Nurul Ilmi mosque.

scholarly journals Diseño de un controlador para sistemas de refrigeración aplicando índice de confort térmico simplificado

2020 ◽  
pp. 30-40
Author(s):  
Francisco Javier Alejo-Chan ◽  
Sósimo Emmanuel Díaz-Méndez ◽  
Hussain Alazki
Keyword(s):  
Mathematical Models ◽  
Thermal Comfort ◽  
Cooling System ◽  
International Standards ◽  
Measuring Instruments ◽  
Comfort Index ◽  
Input Variables ◽  
Standardized Index ◽  
Proportional Controller ◽  
Comfort Indices

This work, the objective is to study a simplified thermal comfort index and apply it to a model of a building with a cooling system in order to check if this simplified comfort index works as a substitute for the standardized index that is indicated in international standards and lead to the decrease in the use of six input variables to only two, which would present a reduction in the number of measuring instruments to be used in real applications. This application presents a Derivative Integral Proportional Controller (PID) to calculate the temperature that satisfies the conditions so that inside the building a comfortable environment is maintained following the scales of the comfort indices. Comparisons of temperatures, thermal comfort scales and percentage of dissatisfied people in both models are required to obtain a validation. The programming of the building’s mathematical models as of the simplified and standard thermal comfort indices is planned to demonstrate based on block diagrams using the software Matlab® on its Simulink platform.

scholarly journals Thermal Comfort Condition in Affandi Museum Yogyakarta

2021 ◽  
Vol 2 (1) ◽  
pp. 20-27
Author(s):  
Azka Millatina ◽  
Nedyomukti Imam Syafii
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Architectural Design ◽  
Research Collaboration ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Primary Data ◽  
Humid Climate ◽  
Artificial Environment ◽  
Temperature Radiation

Thermal comfort is a basic human demand in interacting with space/architectural design. Determination of thermal comfort criteria can help the designer/architect in improving quality, function, and user thermal experience in an artificial environment. ISO 7730: 1994 standard states that the thermal sensation experienced by humans is the result of climate parameters (such as air temperature, radiation temperature, humidity, and wind speed) and human parameters (such as activity and clothing). These parameters were the focus of this study. The work program of this research collaboration was basically divided into 2 phases of activity, namely measuring and monitoring the conditions of thermal comfort in the Gallery 1 environment, Affandi Museum and providing recommendations for improvement of Gallery 1 thermal environment conditions. Primary data was taken from the indoor and outdoor measurement of air temperature, relative humidity and air velocity for 6 months. Physical architectural measurement of this study building and questionnaire methods followed the ASHRAE scale which was simplified to determine the level of thermal comfort, the scale of which was 2 (hot) to -2 (cold). The result of the measurement and analysis using a calculator based upon the ASHARE standard indicated that Gallery 1 of the Affandi Museum was in uncomfortable conditions. While the results of the questionnaire of 20 analyzes showed that at least 87,5% of respondents felt discomfort in Gallery 1, however, 60% of the respondent were still able to enjoy the collection and the atmosphere in gallery 1. The effective temperature index which provide 27,5-27,6 C and 66,7% RH as acceptable indoor environment in warm humid climate at Affandi museum case.

scholarly journals Occupant behavior and thermal comfort field analysis in typical educational research institution: A case study

2018 ◽  
Vol 22 (Suppl. 3) ◽  
pp. 785-795 ◽  
Author(s):  
Nikolina Pivac ◽  
Sandro Nizetic ◽  
Vlasta Zanki
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Educational Research ◽  
Energy Savings ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Co2 Concentration ◽  
Field Analysis ◽  
Occupant Behavior ◽  
Research Institution

An experimental field study has been conducted for typical educational research building facility (office building). The research data was gathered by the systematic monitoring of the offices and adaptive occupant behavior during the typical working day in the spring period. Different sensors and data loggers for temperature, relative humidity, CO2 concentration, had been mounted in order to collect data for analysis of thermal comfort conditions. Moreover, occupant surveys and interviews in form of questionnaire were also brought to examine the psychological and social impacts of the occupants? behavior regarding energy consumption. The inductive scientific method is used for data processing, i. e. descriptive and inferential statistical analysis of the results was made. Based on the analysis of the conducted study, it was found that thermal environment of the observed building is within the standards (i. e. specific parameters are within the range) and that the occupants are generally satisfied with thermal conditions in their offices. However, they do not pay much attention to conserving energy which is an important finding as it is directly related to the energy consumption. Thus, more attention should be directed to the education of the users and in general, to enable energy savings in the future.

Differences of Hemorrhagic and Ischemic Strokes in Age Spectra and Responses to Climatic Thermal Conditions

2020 ◽  
Author(s):  
Pan Ma
Keyword(s):  
Heat Stress ◽  
Cold Stress ◽  
Thermal Environment ◽  
Age Groups ◽  
Additive Model ◽  
Thermal Conditions ◽  
Climate Index ◽  
Thermal Environments ◽  
Distributed Lag ◽  
And Gender

<p>The risks of Emergency Room (ER) visits for cerebral infarction (CI) and intracerebral hemorrhage (ICH) is found to differ in different age groups under different climatic thermal environments. Based on CI and ICH related ER-visit records from three major hospitals in Beijing, China, from 2008 to 2012, the advanced universal thermal climate index (UTCI), was adopted in this study to assess the climatic thermal environment. Particularly, daily mean UTCI was used as a predictor for the risk of ER visits for CI and ICH. A generalized quasi-Poisson additive model combined with a distributed lag non-linear model was performed to quantify their association. The results indicated that (ⅰ) the highest growth rate of ER visits for ICH occurred in age 38 to 48, whereas an increasing ER admissions for CI maintained at age 38 to 78. (ⅱ) The frequency distribution of UTCI in Beijing peaked at -8 and 30 ℃, corresponding to moderate cold stress and moderate heat stress, respectively. (ⅲ) Correlation analysis indicated that ICH morbidity was negatively correlated with UTCI, whereas occurrence of CI showed no significant association with UTCI. (ⅳ) The estimated relative risk of ER visits corresponding to 1℃ change in UTCI, which was then stratified by age and gender, indicated that all sub-groups of ICH patients responded similarly to thermal stress. Namely, there is an immediate ICH risk (UTCI = -13℃, RR=1.35, 95% CIs: 1.11~1.63) from cold stress on the onset day, but non-significant impact from heat stress. As for CI occurrences, no effect from cold stress was identified, except for only those aged 45 to 65 were threatened by heat stress (UTCI = 38℃, RR=1.64, 95% CIs: 1.10~2.44) on lag 0~2d. </p>

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