scholarly journals Comparison of Static Model, Adaptation Study, and CFD Simulation in Evaluating Thermal Comfort Based on Köppen Climate Classification System in Churches in Indonesia

2021 ◽  
Vol 53 (6) ◽  
pp. 210606
Author(s):  
Cornelia Hildegardis ◽  
Anak Agung Ayu Oka Saraswati ◽  
I Dewa Gede Agung Diasana Putra ◽  
Ni Ketut Agusinta Dewi
Keyword(s):  
Thermal Comfort ◽  
Cfd Simulation ◽  
Thermal Sensation ◽  
Static Model ◽  
Model Adaptation ◽  
Air Velocity ◽  
Measuring Point ◽  
Climatic Regions ◽  
Köppen Climate Classification ◽  
Church Buildings

This research examined thermal comfort in  church buildings in Indonesia by making a comparison between three different Indonesian climatic regions using three different research models. A static model, an adaptation study model and a CFD simulation were used to find the similarities and differences between the results generated from determining thermal comfort in church buildings in the three regions. The comparison revealed that church buildings had different PMV scores at each measuring point that were inversely proportional to the subjects’ response on thermal comfort inside the buildings, i.e. points adjoining with openings affect a low PMV score and a high perceived thermal sensation, and vice versa. The CFD simulation showed that changing the conditions of the openings affects air velocity and flow into the building, which influences the subjects’ thermal comfort response inside the churches.

Comparative research on the air pollutant prevention and thermal comfort for different types of ventilation

2020 ◽  
pp. 1420326X2092552
Author(s):  
Yang Zhang ◽  
Wenxuan Yu ◽  
Youli Li ◽  
Han Li
Keyword(s):  
Thermal Comfort ◽  
Cfd Simulation ◽  
Thermal Sensation ◽  
Side Wall ◽  
Air Pollutant ◽  
Indoor Thermal Comfort ◽  
Subjective Experiment ◽  
Different Types ◽  
Computational Fluid Dynamics Cfd ◽  
Indoor Comfort

In this article, a comparative study on the outdoor air pollutant prevention and indoor thermal comfort for different types of ventilation was carried out. Both objective experiment, subjective experiment and computational fluid dynamics (CFD) simulation were conducted to investigate the differences in air pollutant prevention and thermal comfort between four common ventilation methods, namely supplying on the ceiling and returning on the ceiling (SC-RC), supplying on the ceiling and returning on the side wall (SC-RSW), supplying on the side wall and returning on the ceiling (SSW-RC), and supplying on the side wall and returning on the side wall (SSW-RSW). Results show that SSW-RSW can provide the highest indoor air quality according to the indoor average PM2.5 concentration. Overall thermal sensation was introduced to evaluate the indoor comfort under the four ventilation methods. The voting results show that the indoor thermal comfort can be enhanced by 29–36% under SSW-RSW and SSW-RC. Therefore, SSW-RSW is more suitable for providing a healthy and comfortable indoor environment.

The effect of correlated colour temperature of lighting on thermal sensation and thermal comfort in a simulated indoor workplace

2016 ◽  
Vol 27 (3) ◽  
pp. 308-316 ◽  
Author(s):  
Rupak R Baniya ◽  
Eino Tetri ◽  
Jukka Virtanen ◽  
Liisa Halonen
Keyword(s):  
Thermal Comfort ◽  
Room Temperature ◽  
Thermal Sensation ◽  
Light Emitting Diode ◽  
Air Velocity ◽  
Light Emitting ◽  
Colour Temperature ◽  
Test Room ◽  
Illuminance Level ◽  
Colour Rendering

The ‘hue-heat’ hypothesis states that an environment which has wavelengths predominantly toward the red end of the visual spectrum feels ‘warm’ and one with wavelengths mainly toward the blue end feels ‘cool’. In order to test the hypothesis and to study the impacts of the correlated colour temperature of a light source on thermal sensation and thermal comfort, a study was conducted in a test room illuminated with an Light Emitting Diode (LED) lighting system with an adjustable correlated colour temperature where air temperature, air velocity, and relative humidity were kept constant. The correlated colour temperature of lighting inside the test room was changed gradually while keeping the colour rendering index values greater than 90, an illuminance level of 500 lx, and chromaticity difference (Duv) values within the limits of ±0.005. Sixteen study subjects were exposed to a ‘high room temperature’ (25℃) and a ‘low room temperature’ (20℃) on different days. The subjects were adapted to low correlated colour temperature (2700 K), medium correlated colour temperature (4000 K), and high correlated colour temperature (6200 K) lighting for 10 min and subsequently completed the questionnaire about their thermal comfort and thermal sensation. The results of this survey did not provide support for the hue-heat hypothesis and indicated that people felt thermally more comfortable in an indoor workplace at the correlated colour temperature of 4000 K than at the correlated colour temperature of 2700 K or 6200 K.

A Data-Driven Thermal Sensation Model Based Predictive Controller for Indoor Thermal Comfort and Energy Optimization

2014 ◽  
Author(s):  
Xiao Chen ◽  
Qian Wang
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Energy Optimization ◽  
Data Driven ◽  
Air Velocity ◽  
Comfort Index ◽  
Indoor Thermal Comfort ◽  
Occupant Feedback ◽  
Predictive Controller ◽  
Radiant Temperature

This paper proposes a model predictive controller (MPC) using a data-driven thermal sensation model for indoor thermal comfort and energy optimization. The uniqueness of this empirical thermal sensation model lies in that it uses feedback from occupants (occupant actual votes) to improve the accuracy of model prediction. We evaluated the performance of our controller by comparing it with other MPC controllers developed using the Predicted Mean Vote (PMV) model as thermal comfort index. The simulation results demonstrate that in general our controller achieves a comparable level of energy consumption and comfort while eases the computation demand posed by using the PMV model in the MPC formulation. It is also worth pointing out that since we assume that our controller receives occupant feedback (votes) on thermal comfort, we do not need to monitor the parameters such as relative humidity, air velocity, mean radiant temperature and occupant clothing level changes which are necessary in the computation of PMV index. Furthermore simulations show that in cases where occupants’ actual sensation votes might deviate from the PMV predictions (i.e., a bias associated with PMV), our controller has the potential to outperform the PMV based MPC controller by providing a better indoor thermal comfort.

scholarly journals Thermal comfort in the low energy building - validation and modification of the Fanger model

2021 ◽  
Vol 246 ◽  
pp. 15003
Author(s):  
Natalia Krawczyk
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Thermal Sensation ◽  
Carbon Dioxide Concentration ◽  
Low Energy ◽  
Air Velocity ◽  
University Of Technology ◽  
Calculation Results ◽  
Thermal Comfort Model ◽  
The Impact

Nowadays, we spend most of our time inside buildings. Thus, ensuring adequate thermal comfort is an important issue. The paper discusses the issue of thermal comfort assessment in the intelligent low energy building “Energis” of Kielce University of Technology (Poland). The tests conducted in a selected lecture theater focused on collecting anonymous questionnaires containing thermal sensation and air quality votes of the respondents as well as performing measurements of indoor air parameters (air and globe temperatures, relative humidity, air velocity and CO2 concentration). Based on the obtained data a comparison has been done between the actual sensation votes of the volunteers and the calculation results performed with the Fanger thermal comfort model. Two indices have been considered in the paper: PMV (Predicted Mean Vote) and PPD (Predicted Percentage Dissatisfied). A modification of the model has also been proposed, which considers the impact of the carbon dioxide concentration on thermal comfort.

scholarly journals Thermal comfort, thermal sensation and skin temperature measurements using demand-controlled ventilation for individual cooling

2020 ◽  
Vol 172 ◽  
pp. 06001
Author(s):  
Håkon Solberg ◽  
Kari Thunshelle ◽  
Peter Schild
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Energy Demand ◽  
Thermal Sensation ◽  
Air Velocity ◽  
Climate Chamber ◽  
Biometric Data ◽  
Ongoing Research ◽  
Demand Controlled Ventilation ◽  
The Relationship

An increasing part of modern building's energy demand is due to cooling. An ongoing research project investigates the possibility to reduce the energy consumption from cooling by utilizing an individually controlled active ventilation diffuser mounted in the ceiling. This study looks at thermal sensation and thermal comfort for 21 test persons exposed to an innovative user controlled active ventilation valve, in a steady and thermally uniform climate chamber. Furthermore, the relationship between biometric data from the test persons skin temperature and sweat, and the test persons thermal sensation scores has been investigated. Each test person was exposed to three different room temperatures in the climate chamber, 24°C, 26°C and 28°C respectively, to simulate typical hot summer conditions in an office in Norway. At a room temperature of 26°C it was possible to achieve acceptable thermal comfort for most test persons with this solution, but higher air velocity than 0.75 m/s around the test persons bodies at room temperatures of 28°C is required to ensure satisfactory thermal comfort.

A Fan in Winter

1983 ◽  
Vol 27 (8) ◽  
pp. 742-745 ◽  
Author(s):  
Frederick H. Rohles ◽  
Byron W. Jones
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Test Chamber ◽  
Air Velocity ◽  
Subjective Responses ◽  
Human Thermal Comfort ◽  
Significant Difference ◽  
Maximum Period ◽  
Air Space ◽  
Indoor Conditions

In order to determine the effect of ceiling fans on human thermal comfort under winter indoor conditions, 72 subjects (36 men and 36 women) were exposed to 21°C/40% rh for 3 hours while experiencing still air conditions (0.08 m/s) and air velocities where a ceiling fan was operating in a upward-thrust mode at 2 velocities (0.18 and 0.28 m/s). Two subjective responses, thermal sensation and thermal comfort, were recorded each half hour. The results showed that after 2 hours, which may be assumed to be the maximum period of time that an individual would sit without getting up, the subjects recorded (1) the same neutral thermal sensation when the fan was at the still air condition (0.0 8 m/s) as when it was producing an air velocity of 0.18 m/s, (2) a slightly cool thermal sensation at a velocity of 0.28 m/s and (3) no significant difference in thermal comfort between still air (0.08 m/s) and velocities up to 0.28 m/s. It was concluded that the air movement created by operating the ceiling fan under winter conditions does not contribute to nor detract from human comfort nor did it produce any response resembling wind chill. These results were considered conservative since no temperature stratification existed in the test chamber air space which would be expected in exist in a conventionally heated room space.

Cooling with Box Fans

1982 ◽  
Vol 26 (2) ◽  
pp. 123-127
Author(s):  
Eric Rosen ◽  
Stephan Konz
Keyword(s):  
Thermal Comfort ◽  
Room Temperature ◽  
Thermal Sensation ◽  
Office Work ◽  
Air Velocity ◽  
Preferred Direction ◽  
The Subject ◽  
Paper And Pencil ◽  
C 78

Two experiments are described. Experiment 1 investigated the preferred direction of air upon a person. Forty males sat in front of a box fan in 12 different seating orientations (30° increments). Air velocity was .7 m/s (140 ft/min); room temperature was 28 C (82 F) with 40% rh. The preference was bimodal with the most preferred directions from the front or the rear; velocities from the side were less preferred. Experiment 2 investigated 3 velocities (“still air”, .8 m/s (160 ft/min) and 1.3 m/s (260 ft/min)) at 3 temperatures (25.6, 27.8 and 30 C; 78, 82, 86 F). Eight subjects each spent three hours in each of the 9 conditions. Clothing was standardized at about .5 clo. Subjects did a paper and pencil task (maze) and a peg into hole task. Thermal comfort and thermal sensation ballots were completed every 15 min. At the end of 150 min., they moved their chair in relation to the fan so as to select their preferred velocity. The current recommended ceiling of .8 m/s for sedentary office work is too low as the subject-selected velocity was .7 m/s at 25.6 C, was 1.0 m/s at 27.8 C and was 1.2 m/s at 30 C. These results were confirmed by the thermal comfort and thermal sensation ballots. Depending on the criterion used, for seated sedentary work in warm conditions, every 0.1 m/s (20 ft/min) increase in air velocity offsets approximately a 0.4 C (0.7 F) increase in temperature (0.7 < V < 1.2 m/s).

scholarly journals Investigation on Wintry Thermal Comfort in Traditional Houses of Nepalese Three Climatic Regions

2020 ◽  
Vol 15 (3) ◽  
pp. 133-140
Author(s):  
Basudev Gautam ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya
Keyword(s):  
Thermal Comfort ◽  
Thermal Condition ◽  
Building Materials ◽  
Thermal Sensation ◽  
New Technology ◽  
Cold Climate ◽  
Clothing Insulation ◽  
Climatic Regions ◽  
The Mean ◽  
Temperate Climates

The traditional houses are well adapted to the climate and socio-culture using local building materials and techniques. However, traditional practices are being replaced by the artificial materials, modern design and new technology. It requires strong policies to sustain the traditional architecture. The objectives of this study are to evaluate the thermal condition of traditional houses and to estimate the comfort temperature of residents. The thermal comfort survey was conducted during winter in the traditional houses. The thermal sensation votes were collected from 275 people in cold, temperate and sub-tropical climatic regions. This study was revealed that the mean indoor air temperature in cold climatic region is 12.3°C, which was 9.5K and 4.4K lower than sub-tropical and temperate climates. The comfort temperature of the residents in the cold climate was 13.9°C, which was 8.8K and 3.8K lower than sub-tropical and temperate climates. The mean clothing insulation in cold climate was 1.63 clo which was 0.48 clo and 0.31 clo higher than sub-tropical and temperate climates. It concludes that the people were well adapted to each climate with clothing adjustments and made themselves satisfied with the thermal condition of their houses.

scholarly journals Enhancement of Thermal Comfort Inside the Kitchen of Non-Airconditioned Railway Pantry Car

2021 ◽  
Vol 39 (1) ◽  
pp. 275-291
Author(s):  
Md Sarfaraz Alam ◽  
Urmi Ravindra Salve
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Comfort Level ◽  
Air Velocity ◽  
Sustainable Improvement ◽  
Study Results ◽  
Air Ventilation

There are ample literature studies available, focusing on hot-humid built environment, which have achieved an increase in thermal comfort conditions by proper installation of ventilation-systems. The present thermal comfort study has been carried out in the kitchen environment of a non-air-conditioned railway pantry car in Indian Railways. The purpose is to enhance thermal comfort level under the currently applied ventilation system inside the kitchen of pantry car by determining the standard effective temperature (SET) index. During the summer and winter seasons, a field study was carried out to obtain the value of air temperature, globe temperature, relative humidity, and air velocity inside the pantry car for estimation of the SET index. A computational fluid dynamics (CFD) analysis was used to obtain a better-modified case model of the pantry car kitchen for the improvement of thermal comfort. The design interventions for the pantry car kitchen were created, with emphasis on increasing energy efficiency based on low-power consumption air ventilation system. The study results indicated that, modified case-I model has a better ventilation design concept as compare to the existing and other models, which increased the air velocity and significantly decreased the air temperature inside the kitchen of pantry car at all cooking periods. A value of SET (28.6–30℃) was found with a comfortable thermal sensation within all cooking periods, which is better for the pantry car workers. This finding suggests a sustainable improvement in the thermal environment of the "non-air-conditioned" pantry car kitchen in the Indian Railways, which can be applied immediately.

scholarly journals Ventilation Characteristics and Performance Evaluation of Different Window-Opening Forms in a Typical Office Room

2021 ◽  
Vol 11 (19) ◽  
pp. 8966
Author(s):  
Yuanyuan Wang ◽  
Yanzhe Yu ◽  
Tianzhen Ye ◽  
Quan Bo
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Thermal Sensation ◽  
Ventilation Rate ◽  
Window Opening ◽  
Ventilation Modes ◽  
Ventilation Performance ◽  
Scale Experiment ◽  
And Performance

As most existing office buildings in China lack fresh air systems for ventilation, natural ventilation with windows remains the main means of improving indoor air quality and adjusting indoor thermal comfort. However, knowledge of the ventilation characteristics of various window-opening forms in actual buildings is limited and current methods for evaluating ventilation performance lack a comprehensive consideration of ventilation rate and thermal comfort. In this study, the ventilation characteristics of different window-opening forms were systematically compared by conducting computational fluid dynamics (CFD) simulations. A full-scale experiment was conducted in a typical office room in a university in Tianjin to validate the CFD simulation. Two ventilation modes (wind-driven cross-ventilation and temperature-driven single-sided ventilation), three window-opening angles, and seven window types were investigated. Additionally, the ratio of the ventilation rate to the absolute value of thermal sensation was used to quantify the indoor natural-ventilation performance. The results showed that a sliding window with a full opening has the highest discharge coefficients of 0.68 and 0.52 under wind-driven cross-ventilation and temperature-driven single-sided ventilation, respectively, and top-hung windows opening both inwards and outwards have better ventilation performance than other window types under the two ventilation modes. This study is applicable to the design and practice of natural ventilation.

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