Simulation of Thermal Comfort Conditions of an Air-Conditioned Cafeteria in the Tropics

2014 ◽  
Vol 564 ◽  
pp. 263-268
Author(s):  
A. Zainuddin ◽  
Nor Maria Adam ◽  
I.H. Rusli ◽  
Qi Jie Kwong
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Field Measurements ◽  
Cfd Modeling ◽  
Airflow Rate ◽  
Computational Fluid Dynamics Cfd ◽  
Predicted Values ◽  
The Tropics ◽  
Comfort Parameters ◽  
Indoor Comfort

This paper studies the current thermal comfort condition of an air-conditioned cafeteria based on objective measurements and computational fluid dynamics (CFD) modeling. Indoor comfort parameters such as temperature and airflow rate were simulated by a CFD tool. The results from field measurements and predicted values were then compared and contrasted. A simulated model that has the same geometrical configuration as the cafeteria was set as a benchmark model. Several additional models with different configuration of cafeteria layouts were proposed to achieve the required air temperature. It was found that the predicted results from the proposed models showed even distributions of airflow characteristics and temperature gradients. To maintain a thermally-acceptable air temperature of 28 °C, it is proposed that an additional air-conditioning unit be retrofitted to the current cafeteria layout.

scholarly journals An Assessment of the Spatial Comfort at the Open Piazza of Baiturrahman Mosque, Banda Aceh, Indonesia

2020 ◽  
Vol 9 (2) ◽  
pp. 50-62
Author(s):  
Laina Hilma Sari ◽  
Izziah Hasan ◽  
Erna Meutia
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Sensation ◽  
Field Measurements ◽  
Outdoor Thermal Comfort ◽  
Visual Comfort ◽  
Outdoor Air ◽  
White Marble ◽  
The Tropics ◽  
Banda Aceh

 The Baiturrahman Grand Mosque is well-known as the identity of Banda Aceh town, Indonesia. The extensive renovation was carried out in 2015 to the Mosque, presenting an open piazza coated with glossy white marble replacing the previous greeneries and grass. This change creates a much different thermal sensation of the prior environment. This condition also invites the contrast to respond and define spatial comfort, including thermal and visual comfort. Therefore, this study conducts an assessment of thermal and visual comfort at the open piazza, which was done through field measurements. The outdoor thermal comfort was calculated using the equations proposed by Sangkertadi that are appropriate for the tropics. The visual comfort was examined using the De Boer glare scale. The result shows the discomfort appearance for both thermal and visual comfort. The study gives recommendations, such as planting greeneries, providing more shades for achieving lower outdoor air temperature. Replacing the glossy marble with the diffusing and rough surface will reduce the glare for getting the more acceptable visual comfort against the marbles.

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.

scholarly journals KONDISI TERMAL PADA PENGHAWAAN ALAMI DI RUANG TUNGGU UTAMA STASIUN SEMARANG TAWANG

2018 ◽  
Vol 2 (3) ◽  
pp. 144
Author(s):  
Hana Faza Surya Rusyda ◽  
Erni Setyowati ◽  
Gagoek Hardiman
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Research Method ◽  
Thermal Condition ◽  
Natural Ventilation ◽  
Thermal Conditions ◽  
Field Measurements ◽  
Waiting Room ◽  
Train Station ◽  
State Of Mind

Abstract:. Thermal comfort is a state of mind that expresses a user's satisfaction with thermal conditions. This study focuses on the design of natural ventilation which is one of the efforts to reduce the heat that exists in the building, especially in maintaining the thermal conditions. Tawang Train Station, Semarang has a natural ventilation design that is still maintained especially in the waiting room. This study aims to determine the thermal conditions of the design of ventilation using the theory of Mom and Wiseborn, SNI 03-6572-2001, and Olgyay chart. This research method uses quantitative and field measurements were done for 14 hours to know the movement of air, temperature, humidity. The results were then compared with the standard and the theory. It was found that thermal comfort conditions that still utilize the movement of the wind from natural ventilation in the main waiting room of Tawang Semarang Station.Keyword: Thermal Condition, Natural Ventilation, Semarang Tawang Station.Abstrak: Kenyamanan termal merupakan suatu kondisi pikir seseorang yang mengekspresikan kepuasan pengguna terhadap kondisi termal.  Penelitian ini berfokus pada desain penghawaan yang merupakan salah satu upaya mengurangi panas yang ada dalam bangunan terutama dalam menjaga kondisi termal. Stasiun Tawang Semarang, mempunyai desain penghawaan alami yang masih dipertahannkan terutama pada ruang tungguya. Penelitian ini  bertujuan untuk mengetahui kondisi termal dari desain penghawaan dengan menggunakan teori mom dan wiseborn, SNI 03-6572-2001, serta grafik olgyay. Metode penelitian ini menggunakan kuantitatif dan pengukuran dilapangan dilakukan selama 14 jam untuk mengetahui pergerakan udara, temperature, kelembaban. Hasil penelitian kemudian di bandingkan dengan standar SNI, Mom & Wiseborn dan Diagram Olgyay. Ditemukan bahwa kondisi kenyamanan termal yang masih memanfaatkan pergerakan angin dari ventilasi alami pada ruang tunggu utama Stasiun Semarang Tawang.Kata Kunci: Kondisi Termal, Ventilasi Alami, Ruang tunggu, Stasiun Semarang Tawang

CFD-Based Parametric Analysis on the Performance of Personalized Partition Air Distribution Systems

Solar Energy ◽  
2006 ◽  
Author(s):  
Kybum Jeong ◽  
Moncef Krarti ◽  
Zhiqiang Zhai
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Distribution System ◽  
Distribution Systems ◽  
Comfort Level ◽  
Cfd Modeling ◽  
Air Distribution ◽  
Air Velocity ◽  
Comfort Index ◽  
System Mode

The partition air distribution systems evaluated in this study allow occupants to control the system mode (on/off) and the supply air velocity and direction with similar flexibility as occupants in automobiles. To find optimal specifications for the partition air distribution systems that are able to achieve comfortable micro-environment, a CFD modeling tool was used to simulate the airflow and thermal performance of the partition air distribution systems in a typical office space. By analyzing the distribution characteristics of indoor air temperature, air velocity and thermal comfort index, the study assessed the performance of the partition air distribution systems with different operating parameters. The simulation results were analyzed and evaluated to assess both occupant’s thermal comfort and system energy consumption. The study shows that space cooling energy can be reduced while maintaining acceptable indoor thermal comfort level using a partition air distribution system with a higher supply air temperature.

scholarly journals The Effect of Tree-Planting Patterns on the Microclimate within a Courtyard

2019 ◽  
Vol 11 (6) ◽  
pp. 1665 ◽  
Author(s):  
Junying Li ◽  
Jiying Liu ◽  
Jelena Srebric ◽  
Yuanman Hu ◽  
Miao Liu ◽  
...  
Keyword(s):  
Air Temperature ◽  
Local Heat Transfer ◽  
Field Measurements ◽  
Weather Conditions ◽  
Local Heat ◽  
Tree Planting ◽  
Cfd Model ◽  
Planting Pattern ◽  
Wind Velocities ◽  
Computational Fluid Dynamics Cfd

Current landscape design within a courtyard usually does not take into account the influence of the tree-planting pattern, which has an important influence on the outdoor microclimate and occupants’ thermal comfort. At present, the extent of the influence on the microclimate has not yet been made clear. Computational Fluid Dynamics (CFD) was employed to run this model under hot summer weather conditions. Field measurements validated the performance of the CFD model. This study conducted numerical simulations for five different tree-planting patterns, including (i) focused tree-planting (F), (ii) cornered tree-planting (C), (iii) multi-row tree-planting (R), (iv) surround tree-planting (S) and (v) no tree-planting (N). Our study found that the tree-planting pattern affects both the distribution of air temperature and the degree of local heat transfer. Specifically, the C, S and N patterns allow for higher ventilation in the studied courtyard, while the F and R patterns cause lower wind velocities and associated courtyard ventilation. The average air temperature for the C pattern is lower during summer afternoons than the other patterns. The wind flow pattern in the studied courtyard does not vary significantly with different tree-planting patterns. Nevertheless, the general relative humidity in the courtyard does not vary significantly with different tree-planting patterns, except for the N pattern. A future analysis is needed to investigate the mechanisms of the phenomenon.

scholarly journals Determination of thermal and acoustic comfort inside a vehicle’s cabin

2018 ◽  
Vol 32 ◽  
pp. 01002
Author(s):  
Alexandra Ene ◽  
Tiberiu Catalina ◽  
Andreea Vartires
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
The Other ◽  
Air Velocity ◽  
Acoustic Comfort ◽  
Comfort Parameters

Thermal and acoustic comfort, inside a vehicle’s cabin, are highly interconnected and can greatly influence the health of the passengers. On one hand, the H.V.A.C. system brings the interior air parameters to a comfortable value while on the other hand, it is the main source of noise. It is an intriguing task to find a balance between the two. In this paper, several types of air diffusers were used in order to optimize the ratio between thermal and acoustic interior comfort. Using complex measurements of noise and thermal comfort parameters we have determined for each type of air diffuser the sound pressure level and its impact on air temperature and air velocity.

scholarly journals CFD-modeling of fume formation in kraft recovery boilers

TAPPI Journal ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 25-32 ◽  
Author(s):  
AINO LEPPÄNEN ◽  
ERKKI VÄLIMÄKI ◽  
ANTTI OKSANEN ◽  
HONGHI TRAN
Keyword(s):  
Field Measurements ◽  
Enrichment Factors ◽  
Cfd Modeling ◽  
Cfd Model ◽  
Metal Chemistry ◽  
Kraft Recovery Boilers ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Potassium Enrichment ◽  
Particle Mass Concentration

A computational fluid dynamics (CFD) model was developed to simulate alkali metal chemistry and fume particle formation in a kraft recovery boiler. The modeling results were partially validated against previously obtained field measurements. The model provides information about fume composition, chlorine and potassium enrichment factors, and particle mass concentration at different locations in the boiler.

scholarly journals How Parks Provide Thermal Comfort Perception in the Metropolitan Cores; A Case Study in Madrid Mediterranean Climatic Zone

2020 ◽  
Author(s):  
Farshid Aram ◽  
Ebrahim Solgi ◽  
Sepideh Baghaee ◽  
Ester Higueras García ◽  
Amir Mosavi ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Field Measurements ◽  
Urban Heat Islands ◽  
Cooling Effect ◽  
P Value ◽  
Physical And Mental Health ◽  
Physiological Equivalent Temperature ◽  
Urban Green Spaces ◽  
Urban Heat

The combined effects of global warming and increasing urban heat islands (UHIs) on air temperature and heat stress in cities are notable physical and mental health implications for citizens. With research having shown the effective role of urban green spaces in decreasing urban heat, this study investigated the cooling effect of a large urban park on thermal comfort outside the park area, from psychological and physiological perspectives. The studied park is located in the center of Madrid and adjacent to UHI. The study was performed by conducting field measurements and a survey with questionnaires. The measurements made on six summer days (with two-week intervals) showed that the park’s cooling effect could decrease the air temperature by 2.4-2.8°C right up to the edge of the heat island (600m), and decrease the physiological equivalent temperature (PET) by about 3.9°C. By decreasing air temperature and PET, this park was also shown to increase the perceived thermal comfort (PTC) of the citizens from the psychological perspective in the defined area of effect. This perceived thermal comfort was found to have a significant inverse relationship with PET (P-value <0.05). The examination of cognitive maps drawn by citizens showed that out of the 145 respondents, 68.3% marked the park as the area that they perceive as having the greatest thermal comfort, and prefer as the place to spend time enjoying thermal comfort, irrespective of its distance from their location.

scholarly journals Thermal Comfort Analyses in Naturally Ventilated Buildings

2014 ◽  
Vol 10 (3) ◽  
pp. 60-66 ◽  
Author(s):  
Ioana Udrea ◽  
Cristiana Croitoru ◽  
Ilinca Nastase ◽  
Angel Dogeanu ◽  
Viorel Badescu
Keyword(s):  
Thermal Comfort ◽  
Thermal Regime ◽  
Field Survey ◽  
Thermal Sensation ◽  
Residential Buildings ◽  
Experimental Results ◽  
Current Requirement ◽  
Naturally Ventilated Buildings ◽  
Comfort Parameters ◽  
Indoor Comfort

Abstract Global current requirement is to increase thermal comfort in residential and non residential buildings. A field survey was accomplished in a naturally ventilated university classroom in Bucharest, Romania, in winter and spring. Comfort parameters were measured and comfort questionnaires were distributed to the students. Questions were related to thermal sensation of the occupants. This paper compares the experimental results with the occupant’s response. It analyzes the variation of Predicted Mean Vote (PMV) and Predicted Percent of Dissatisfied (PPD) with temperature. It is made a comparison between PMV and thermal sensation vote. The results show PMV values different from Thermal Sensation Vote (TSV) values which means there is a poor approximation of indoor comfort. In conclusion the comfort parameters should be reviewed and should be proposed other evaluation methods. Possible explanations are discussed in relation with thermal regime of the buildings.

CFD Investigation of Air Flow Patterns and Thermal Comfort in a Room with Diverse Heating Systems

2019 ◽  
Vol 6 (2) ◽  
pp. 150-158
Author(s):  
Mohammed Sobhi ◽  
Essam E. Khalil
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Cfd Simulation ◽  
Thermal Environment ◽  
Ventilation Rate ◽  
Current Work ◽  
Medium Temperature ◽  
Heating Systems ◽  
Computational Fluid Dynamics Cfd ◽  
Temperature Heating

Objective: The main focus in the current work is to investigate how diverse heating systems and their locations influence the indoor thermal environment in an exhaust- ventilated room. Methods: Four systems for heating the room were used in the current study, in which, heat was transferred by convection and radiation. The four systems were: wall and floor heating at low temperatures, Medium Temperature Radiator (M.T. radiator) heating and High Temperature Radiator (H.T. radiator). Computational Fluid Dynamics (CFD) simulation was used to investigate indoor temperature, vertical air temperature gradient and thermal comfort for each case. The ventilation rate was set to be 6 air changes per hour (ACH) entering the room through a vent over the window. Results: The findings from the current work were that the low temperature heating systems had better temperature distributions with lower vertical Air Temperature Differences compared to high and medium temperature radiator systems. Conclusion: The Predicted Mean Vote (PMV) and the predicted percentage of dissatisfied (PPD) based on Fanger’s model were calculated for all cases, and were found to be in the recommended ranges.

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