scholarly journals Effects of Supply Angle on Thermal Environment of Residential Space with Hybrid Desiccant Cooling System for Multi-Room Control

2020 ◽  
Vol 10 (20) ◽  
pp. 7271
Author(s):  
Joon Ahn ◽  
Ho Yup Choi
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Cooling System ◽  
Living Room ◽  
Comfort Zone ◽  
Computational Fluid Dynamics Cfd ◽  
Dining Room ◽  
Typical Summer ◽  
Globe Temperature ◽  
American Society

In this study, local measurement and computational fluid dynamics (CFD) were employed to evaluate the thermal comfort in a residential environment where desiccant cooling is performed in an outdoor air condition, which is the typical summer weather in Korea. The desiccant cooling system in the present study has been developed for multi-room control with a hybrid air distribution, whereby mixing and displacement ventilation occur simultaneously. Due to this distribution of air flow, the thermal comfort was changed, and the thermal comfort indicators conflicted. The evaluation indicators included the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) comfort zone, predicted mean vote (PMV), and effective draft temperature (EDT). The dry-bulb temperature displayed a distribution of 26.2–26.8 °C in the cooling spaces, i.e., living room, kitchen, and dining room. When determined based on the standard ASHRAE comfort zone, the space where desiccant cooling takes place entered the comfort zone for summer. Due to the influence of solar radiation, the globe temperature was more than 2 °C higher than the dry-bulb temperature at the window. A difference of up to 6% in humidity was observed locally in the cooling space. In the dining room located along the outlet of the desiccant cooling device, the PMV entered the comfort zone, but was slightly above 1 in the rest of the space. Conversely, as for the EDT, its value was lower than −1.7 in the dining room, but was included in the comfort zone in the rest of the space. By adjusting the discharge angle upward, the PMV and EDT were expected to be more uniform in the cooling space. In particular, the optimum discharge angle obtained was 40° upward from the discharge surface.

scholarly journals Analysis of the Wind Environment to Improve the Thermal Comfort in the Colonnade Space of a Qilou Street Based on the Relative Warmth Index

2019 ◽  
Vol 11 (16) ◽  
pp. 4402 ◽  
Author(s):  
Xianfeng Huang ◽  
Zhen Lu ◽  
Zhixiang Zhuang
Keyword(s):  
Wind Speed ◽  
Thermal Comfort ◽  
Architectural Design ◽  
Thermal Environment ◽  
Transitional Space ◽  
Wind Environment ◽  
Warmth Index ◽  
Research Findings ◽  
Building Components ◽  
Computational Fluid Dynamics Cfd

By analyzing measurements of the thermal environment of a qilou (arcade building) street, this study used the relative warmth index (RWI) to evaluate the thermal comfort in the colonnade space of a qilou. The analysis of the influence of the temperature, humidity, and wind speed on the thermal comfort in the colonnade space of a qilou street was conducted, and it was shown that the ambient wind speed had a strong influence on the RWI, indicating that a proper increase in the wind speed positively affected thermal comfort in this space. Then, this study also analyzed the effects of different forms of qilou streets on the wind environment by employing computational fluid dynamics (CFD) and summarized the architectural design measures that can improve the thermal comfort, including adopting back chamfer, street gaps, and the appropriate sizing of building components. It was concluded that the wind environment of a qilou could be optimized in terms of these measures, and the average RWI value decreased by 0.06, effectively enhancing the thermal comfort in the colonnade space. The research findings are applicable toward designing a thermally comfortable environment in the transitional space.

MAPEAMENTO DE CONTORNO BIOCLIMÁTICO EM AVIÁRIO DE REGIÃO TROPICAL NA CIDADE DE DRACENA/SP

2018 ◽  
Vol 33 (1) ◽  
pp. 52
Author(s):  
Robert Guaracy Aparecido Cardoso Araujo ◽  
Leda Gobbo de Freitas Bueno ◽  
Silvia Regina Lucas de Souza
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Tropical Region ◽  
Poultry Production ◽  
Poultry Facilities ◽  
Relative Air Humidity ◽  
Bioclimatic Variables ◽  
Different Seasons ◽  
Globe Temperature ◽  
Equidistant Points

O ambiente dentro dos galpões avícolas é um dos fatores primordiais para se conseguir bons índices zootécnicos e retornos financeiros. Assim, o objetivo deste estudo foi avaliar o ambiente térmico no interior do galpão de aves poedeiras em diferentes estações do ano na tentativa de proporcionar uma melhor relação ao bem-estar das aves. O estudo foi realizado no galpão de aves poedeiras na UNESP - campus de Dracena/SP. Foram distribuídos e aferidos em doze pontos equidistantes as principais variáveis bioclimáticas, como temperatura de globo negro, temperatura do ar, temperatura de bulbo seco, temperatura de bulbo úmido, temperatura de superfície de telhado, umidade relativa do ar e velocidade do vento. As medições foram feitas nas transições entre as estações do inverno e primavera, primavera e verão e verão e outono, com o intuito de observar qual é a melhor estação do ano em que as aves apresentam um melhor conforto térmico dentro das instalações avícolas. As médias das variáveis bioclimáticas foram comparadas utilizando o teste estatístico Tukey (95%) através do software Statigrafics Centurion, e o software de superfície SURFER para o mapeamento do aviário. Os resultados indicaram que a transição entre inverno e primavera apresentou melhores valores com relação ao conforto térmico dentro do galpão, possibilitando um melhor bem-estar das aves e consequentemente melhor desempenho e retorno financeiro.PALAVRAS-CHAVES: Ambiência, Aquecimento Global, Ondas De Calor, Zootecnia De Precisão. MAPPING BIOCLIMATIC CONTOUR OF A POULTRY SHED IN A TROPICAL REGION IN THE CITY OF DRACENA/SPABSTRACT: The environment inside poultry houses is one of the main factors to achieve good zootechnical indexes and financial returns. Thus, the objective of this study was to evaluate the thermal environment inside the shed of laying hens in different seasons of the year in an attempt to provide a better relation to the welfare of birds. The study was carried out in the poultry shed at UNESP campus in Dracena / SP. The main bioclimatic variables, such as black globe temperature, air temperature, dry bulb temperature, wet bulb temperature, roof surface temperature, relative air humidity and wind speed were distributed and measured at twelve equidistant points. The measurements were taken at the transition between the seasons of winter and spring, spring and summer and summer and fall, in order to obtain the best season of the year in which the birds can obtain better thermal comfort inside the poultry facilities. The averages of the bioclimatic variables were compared using the Tukey statistical test (95%) using the Statigrafics Centurion software, where the SURFER surface software was used to map the aviary. The results indicated that the transition between winter and spring presented better values with respect to thermal comfort inside the shed, allowing a better welfare of the birds and consequently better performance and financial return.KEYWORDS: Environment, Global Warming, Heatwaves, Precision Poultry Production.

scholarly journals Analyzing the Effect of Water Body on the Thermal Environment and Comfort at Indoor and Outdoor Spaces in Tropical University Campus

2021 ◽  
Vol 12 (10) ◽  
pp. 282-288
Author(s):  
Farhadur Reza ◽  
◽  
Shoichi Kojima ◽  
Wataru Ando
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Outdoor Thermal Comfort ◽  
University Campus ◽  
Clothing Insulation ◽  
Comfort Index ◽  
Outdoor Spaces ◽  
Globe Temperature ◽  
And Performance ◽  
University Spaces

Water bodies play a significant role in its surrounding thermal environment. Thermal comfort in university spaces is critical that affects the students’ health and performance as well as the staffs. This study investigated thermal environment and comfort near lakeside and non-lakeside tropical university spaces. Standard Effective Temperature (SET*) have been calculated using recorded air temperature, relative humidity, globe temperature, air velocity, clothing insulation and metabolic rate to evaluate the thermal comfort in outdoor and indoor spaces. The effects of weather parameters have been clearly visible on the comfort index. The calculated SET* values indicate that the outdoor thermal comfort near a lake is much closer to the standard comfort zone than non-lakeside outdoor space. In the case of indoor thermal comfort, however, slightly a different scenario has been observed. To achieve the desirable indoor thermal environment, some design considerations are recommended based on findings.

scholarly journals Summer sleep quality and change of bedroom thermal environment – from the beginning to the end of sleep

2019 ◽  
Vol 111 ◽  
pp. 06054
Author(s):  
Noriko Umemiya ◽  
Kurumi Yamagata ◽  
Tomohiro Kobayashi
Keyword(s):  
Sleep Quality ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Subjective Sleep Quality ◽  
Wet Bulb Globe Temperature ◽  
Subjective Sleep ◽  
Environment Changes ◽  
Globe Temperature

Relations between bedroom thermal environment changes and subjective sleep quality and thermal comfort were surveyed for 63 apartment occupants during midsummer in Osaka. Changes of Wet Bulb Globe Temperature (WBGT) of 123 air-conditioned and 41 naturally ventilated nights were compared. 1) For air-conditioned bedrooms, sleep quality was better for smaller changes of WBGT from the beginning of sleep and for faster changes of WBGT to constant from the beginning of sleep. 2) For naturally ventilated bedrooms, a) WBGT increased from the beginning of sleep and decreased toward the end of sleep for higher sleep quality nights. However, WBGT decreased from the beginning of sleep and increased toward the end of sleep for lower sleep quality nights. b) The WBGT change was smaller for thermally comfortable nights.

scholarly journals Thermal comfort indices in individual shelters for dairy calves with different types of roofs

2011 ◽  
Vol 31 (6) ◽  
pp. 1044-1051 ◽  
Author(s):  
Patrícia C. de F Fonseca ◽  
Eduardo A. de Almeida ◽  
Roberta Passini
Keyword(s):  
Thermal Comfort ◽  
Building Materials ◽  
Statistical Difference ◽  
Thermal Environment ◽  
Dairy Calves ◽  
Asbestos Cement ◽  
Humidity Index ◽  
Globe Temperature ◽  
Materials Used ◽  
Comfort Indices

Among the building materials used in rural facilities, roofs are noteworthy for being largely responsible for thermal comfort, influencing the thermal balance within the shelter. This study aimed to evaluate the influence of roof on the Enthalpy (H), Thermal Load of Radiation (TLR), and Black Globe Temperature and Humidity Index (BGHI) in individual shelters for dairy calves. The design was completely randomized with three treatments: Z - zinc tile, AC - asbestos-cement tile and ACW - asbestos-cement tile painted white on the upper side. The averages were compared by the Scott Knott test at 1% probability. The results showed no statistical difference between treatments (P<0.01) and the external environment for H. For TLR, there was statistical difference among all treatments, where ACW showed the lowest TLR, 489.28 W m-2, followed by AC with 506.72 W m-2 and Z with the highest TLR, 523.55 W m-2. For BGHI, the lowest values were observed for ACW (76.8) and AC (77.4), differing significantly from Z, which obtained the highest value (81.6). The tiles with white paint on the upper side promoted the lowest TLR and the lowest BGHI, favoring the thermal environment in the shelter.

scholarly journals Thermal comfort findings: Scenario at Malaysian automotive industry

2013 ◽  
Vol 17 (2) ◽  
pp. 387-396 ◽  
Author(s):  
Ahmad Ismail ◽  
Kumar Karagaratnan ◽  
Kumaran Kadirgama
Keyword(s):  
Thermal Comfort ◽  
Automotive Industry ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Human Subjects ◽  
Demographic Data ◽  
Working Environment ◽  
Paint Shop ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature

This paper discusses the findings of thermal comfort assessment at Malaysian automotive industry. Nine critical workstations were chosen as subjects for the study in order to determine the thermal comfort among workers at Malaysian automotive industry. The human subjects for the study comprises of the operators from tire receiving, dashboard assembly, drum tester, body assembly, seat assembly, door check assembly, stamping workstation, engine sub assembly and paint shop of the factory. The environmental factors such as Wet Bulb Globe Temperature (WBGT), relative humidity, air velocity, illuminance were measured using BABUC A apparatus and Thermal Comfort Measurement equipment. Through questionnaire survey, the demographic data of subjects and their perceptions on thermal comfort at each workstation were assessed based on ISO Standard 7730 and thermal sensation scale using Predicted Mean Vote (PMV). Then, Predicted Percentage of Dissatisfied (PPD) is used to estimate the thermal satisfaction of occupants. The results indicated that most of the workstations of the automotive industry are considered as uncomfortable. Tire receiving station is considered having better working environment compared to other stations with lowest PMV index of 1.09 to 1.41 and PPD of 46%. Meanwhile, the engine sub assembly station and paint shop of assembly are considered the worst thermal environment with the PMV index values ranging between 2.1 to 2.9 and PPD values of 81% to 99%. Therefore, these two workstations are considered not comfortable because the thermal sensation scale is warm and almost hot.

scholarly journals CONFORTO TÉRMICO E DESEMPENHO DE LEITÕES CRIADOS EM GAIOLAS ENRIQUECIDAS COM PISO DE RESÍDUOS DE EVA (ETILENO-ACETATO DE VINILA)

2019 ◽  
Vol 34 (2) ◽  
pp. 230-240 ◽  
Author(s):  
Silvia Noelly Ramos de Araújo ◽  
José Pinheiro Lopes Neto ◽  
José Wallace Barbosa do Nascimento ◽  
Fernanda Fernandes de Melo Lopes ◽  
Maria Luíza de Souza Rezende
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Productive Performance ◽  
Weaned Piglets ◽  
Alternative Material ◽  
Globe Temperature ◽  
And Performance ◽  
Comfort Indices ◽  
Black Globe Temperature

CONFORTO TÉRMICO E DESEMPENHO DE LEITÕES CRIADOS EM GAIOLAS ENRIQUECIDAS COM PISO DE RESÍDUOS DE EVA (ETILENO-ACETATO DE VINILA)   SILVIA NOELLY RAMOS DE ARAÚJO1, JOSÉ PINHEIRO LOPES NETO2, JOSÉ WALLACE BARBOSA DO NASCIMENTO3, FERNANDA FERNANDES DE MELO LOPES4, MARIA LUIZA DE SOUZA REZENDE5   Engenharia Agrícola, Universidade Federal de Campina Grande, Rua Aprígio Veloso, 882 – Universitário, 58429-900, Campina Grande, Paraíba, Brasil, [email protected]; [email protected]; [email protected]; [email protected]; [email protected].   RESUMO: Objetivou-se analisar o conforto térmico de leitões na fase de creche, mantidos em instalações com piso de placas de resíduos EVA, utilizadas para reduzir a transferência de calor dos animais para a superfície de contato, utilizando-se 24 leitões desmamados, com idade média de 23 + 2 dias, distribuídos em 8 baias, utilizando-se dois tipos de pisos: tratamento 1- Placas de EVA + piso plástico vazado e o tratamento 2- piso plástico vazado. O delineamento experimental foi inteiramente casualizado (DIC) e a comparação entre as médias através do teste de Tukey (P<0,05). A caracterização do ambiente térmico foi realizada por meio do registro da temperatura do ar, umidade relativa, temperatura de globo negro, luminosidade e velocidade do vento. Para a análise do conforto térmico proporcionado pelos pisos utilizou-se os índices de conforto térmico (temperatura de globo negro e umidade e a carga térmica de radiação), o mapeamento térmico superficial (pisos e leitões) e o desempenho produtivo dos animais. Os resultados indicaram que, as placas sobre o piso mostraram ser eficiente na redução da transferência de calor sensível entre o piso-leitão, o que tornou o aquecimento mais eficaz para os animais.   Palavras-chaves: conforto térmico, creche suína, material alternativo, piso plástico.   THERMAL COMFORT AND PERFORMANCE OF PIGLETS CREATED IN ENRICHED CAGES WITH EVA WASTE FLOOR (VINYL ETHYLENE ACETATE)   ABSTRACT: The aim of this study was to analyze the thermal comfort of piglets in nursery phase, maintained in systems with EVA waste plates floor, used to reduce the animal heat transfer to the contact surface, using 24 weaned piglets, average age 23 + 2 days, distributed in 8 bays, using two types of floors: treatment 1: EVA plates + leaked plastic floor and treatment 2: leaked plastic floor. The experimental design was completely randomized (CRD) and the means were compared using Tukey's test (P<0.05). The characterization of the thermal environment was performed by recording the air temperature, relative humidity, black globe temperature, luminosity and wind speed. Thermal comfort indices (black globe temperature and humidity and thermal radiation load), thermal thermal mapping (floors and piglets) and the productive performance of animals were used to analyze the thermal comfort provided by the floors. The results indicated that the boards on the floor were shown to be efficient in reducing the transfer of sensible heat between the floor-piglet, which made heating more effective for the animals.   Keywords: thermal comfort, nursery, alternative material, plastic floor.

Conserving Energy by Expanding the Thermal Comfort Envelope

1978 ◽  
Vol 22 (1) ◽  
pp. 533-536 ◽  
Author(s):  
Frederick H. Rohles
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Heating And Cooling ◽  
American Society ◽  
Psychrometric Chart ◽  
Sedentary Activities

Standard 55–74 entitled “Thermal Conditions for Human Occupancy” which is published by The American Society of Heating, Refrigerating, and Air Conditioning Engineers, (ASHRAE) defines an “acceptable thermal environment” as one in which “at least 80 percent of the normally clothed men and women while engaged in indoor sedentary or near sedentary activities would express thermal comfort.” This is pictured on the ASHRAE psychrometric chart as an envelope that includes dry bulb temperatures between 74°F and 77°F at relative humidities between 20% and 60%. The paper will describe five human factors approaches that have been used or are being considered to expand this envelope and thereby conserve energy. These are (1) the use of small radiant heaters which are installed in the modesty panels of desks so comfort may be attained at lower temperatures; (2) the demonstration that night set-back of thermostats to temperatures as low as 50°F do not effect sleeping patterns; (3) the role that interior decor can play in making people feel warmer; (4) the effect that temperature “swings” associated with solar heating and cooling has upon acceptance of the thermal environment and (5) the acceptance of a reduced quality of indoor air as a result of heating with an increased ratio of recirculated air to outside air.

scholarly journals Study on the Performance of Adjustable Platform Screen Door in Subway Stations

2020 ◽  
Vol 172 ◽  
pp. 24008
Author(s):  
Su Ziyi ◽  
Li Xiaofeng ◽  
Zhang Yue
Keyword(s):  
Thermal Comfort ◽  
Cfd Simulation ◽  
Rapid Progress ◽  
Comfort Zone ◽  
Thermal Discomfort ◽  
Warmth Index ◽  
Computational Fluid Dynamics Cfd ◽  
Subway Stations ◽  
Arrival Pattern ◽  
Occupied Zone

In the last decades, the construction of subway systems has been in rapid progress in metropolis. Former studies have pointed out that substantial amount of energy is consumed by subway stations. Thus, the adjustable platform screen door (APSD) system is widely adopted, which is characterized by the energy-saving in both the cooling season and the transitional season. However, the installation of APSD system might result in thermal discomfort for passengers, which lacks investigation. This study aims to study the performance on the thermal comfort of subway station with APSD system. In this process, Computational Fluid Dynamics (CFD) Simulation was conducted using PHOENICS to obtain the velocity and temperature distribution under 3 kinds of train arrival patterns. Furthermore, Relative Warmth Index (RWI) was used to assess thermal comfort. The results show that the velocities of the platform and station hall are below 2.5m/s and 3.7m/s respectively, which is closely related to the train arrival pattern. With regard to the platform occupied zone, the RWI is between 0.04 to 0.19, which is almost within the thermal comfort zone according to the ASHRAE comfort classification. Nevertheless, for the occupied zone of the hall, the RWI is between 0.15 to 0.52, indicating relatively warm.

Summer thermal comfort and overheating in the elderly

2019 ◽  
Vol 40 (4) ◽  
pp. 426-445 ◽  
Author(s):  
Caroline Hughes ◽  
Sukumar Natarajan
Keyword(s):  
Thermal Comfort ◽  
Elevated Temperatures ◽  
Thermal Conditions ◽  
The Elderly ◽  
Vulnerable Groups ◽  
Climate Projections ◽  
Living Room ◽  
Warm Summer ◽  
Typical Summer ◽  
The Impact

Atypically warm summers such as 2003 and 2018 are predicted to become normal by 2050. If current climate projections are accurate, this could cause heat-related mortality to rise by 257% by 2050, the majority of which will be in vulnerable groups such as the elderly. However, little is known about the temperatures achieved in the homes of the elderly even in typical summers, and even less on whether these are comfortable. This study examines, for the first time, the validity of current thermal comfort models in predicting summer comfort levels in the 65+ demographic over a typical and an atypically warm summer. This was achieved through the first longitudinal study of thermal conditions in homes of the elderly in the South West UK, utilising repeated standardised monthly thermal comfort and health surveys with continuous temperature monitoring in both living and bed rooms. Results show that neither the PMV/PPD model (ISO 7730) nor the adaptive model (ISO 15251) accurately predict true thermal comfort in our sample. Overheating analysis using CIBSE TM59 (based on ISO 15251) suggests significantly more homes (50% living room, 94% bed room = 94% overall) overheated during the atypically warm summer, compared to the typical summer (3% living room, 57% bed room = 57% overall). These are worrying results, especially for the elderly, given the projected increases in both the severity and the frequency of extreme summers in a future, changed, climate. Practical application: This paper provides new data on the performance of the homes of the elderly in both a typical and atypically warm summer. Our results could be considered for building performance evaluation in homes with elderly occupants to mitigate overheating risk. Crucially, we not only examine the impact of CIBSE criteria on these homes but also look at thermal acceptance, which is important to understand the true impact of elevated temperatures in this demographic.

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