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

Solar Energy ◽  
2006 ◽  
Author(s):  
Kybum Jeong ◽  
Moncef Krarti ◽  
Zhiqiang Zhai

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.

2016 ◽  
Vol 26 (10) ◽  
pp. 1382-1396 ◽  
Author(s):  
Eusébio Z. E. Conceição ◽  
Cristina I. M. Santiago ◽  
Hazim B. Awbi

This paper presents a comparative numerical study of different ceiling-mounted-localized air distribution systems placed above students in a virtual classroom in summer conditions. The influence of four different ceiling-mounted-localized air distribution systems, using vertical descendent jets, on the thermal comfort, local thermal discomfort, and air quality levels was numerically evaluated. The air distribution index, developed previously, was used for non-uniform environment. This index considers the thermal comfort level, air quality level, effectiveness for heat removal, and effectiveness for contaminant removal. Numerical simulations were conducted for a virtual classroom equipped with one of four different ceiling-mounted-localized air distribution systems and with 6 desks, 6 or 12 students, and 2 upper airflow outlets. Inlet air supply temperature of 20 and 24℃ and an outdoor air temperature of 28℃ were used. The simulation results show that the air supply system having a vertical air jet placed at 1.8 m above the floor level (Case III), and with an inlet area of 0.01 m2 and a supply air velocity of 3 m/s would represent the best option in comparison with other air supply methods. In general, the air distribution index value decreases with an increase in inlet air temperature and the number of occupants. The air distribution index values are highest for Case III representing a classroom with 6 or 12 occupants with an inlet air temperature of 20 or 24℃.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.


Author(s):  
Hamza Begdouri ◽  
Luis Rosario ◽  
Muhammad M. Rahman

This study considers airflow simulations to evaluate the impact of different window air-conditioner locations on the thermal comfort in an office rooms (OR). This paper compares the air distribution for an office room by using computational fluid dynamics (CFD) modeling. The air distribution was modeled for a typical office room window air conditioning unit, air supply from a high pressure on the top and the low pressure exhaust on the bottom considering the existing manufacturing ratios for surface areas. Calculations were done for steady-state conditions including an occupant and a light source. The discharge angle for the supply grill of the AC unit was varied from 20 to 40 degrees. The position of the air conditioner was also varied and studied at 60%, 75% and 90% of the total height of the room. In addition the location of the occupant within the office room was varied. Predictions of the air movement, room temperature, room relative humidity, comfort level, and distribution of contaminants within the office room are shown. Analysis of these simulations is discussed. The positions of the air-conditioner unit, the inlet angle and the occupant position in the office room have shown to have important impacts on air quality and thermal comfort. Results are in good agreement with available experimental data.


Author(s):  
Anastacio Silva Junior ◽  
Nathan Mendes ◽  
Rogério Vilain ◽  
Marcelo Pereira ◽  
Katia Cordeiro Mendonça

Abstract Thermal comfort conditions may vary substantially within an air-conditioned room equipped by split-type systems. In this work, the comfort conditions in a classroom were evaluated experimentally based on the PMV index, according to ISO 7730 Standard that defines the thermal satisfaction in occupied environments. The experiment was carried out at three different supply airflows (high, medium and low) and three set-point temperatures (23, 24 and 25°C). The results showed that there is a considerable variation in the air velocity field in the room as well as in the PMV values for three different supply airflows, consequently significant changes of thermal comfort indices can be noticed. Several curves were adjusted aiming to express the values of PMV, deriving a simplified comfort index for rooms conditioned by split-type systems based on dry-bulb air temperature and air speed. The purpose of this adjustment is to obtain an equation that provides the value of the comfort index for cooling purposes. Thus, for a certain condition of use, one can predict what will be the value of PMV in an occupied environment, enabling the implementation of a control system of the comfort according to this new index (ICS). The variables considered in obtaining the curve were the air temperature (Tar) and the air velocity (Var), since these two variables can be controlled directly by the split-type system. The general purpose of this work is to provide experimental data for the development of a low-cost device to automatically control ICS-based thermal comfort in a space conditioned by a split-type system through a single and representative point within the classroom.


2021 ◽  
Vol 39 (1) ◽  
pp. 275-291
Author(s):  
Md Sarfaraz Alam ◽  
Urmi Ravindra Salve

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.


2014 ◽  
Vol 663 ◽  
pp. 474-479
Author(s):  
Mohd Anas Mohd Sabri ◽  
Mohd Faizal Mat Tahir ◽  
Kamaruzaman Sopian ◽  
Muhammad Hadi Zabidi Rosdi

The successful of manufacturing factories in industry is highly dependent on a productivity of their employees especially operators. It was identified that comfort and noise level can reduce the productivity of their workers. This study is to determine the level of thermal and noise comfort in the battery plate factory. This study was conducted in three days and location of the study is at battery plate factory in Semenyih, Selangor, Malaysia. The scope of study is focused at plate manufacturing area where the employee estimated 40 persons. The thermal comfort level can be determined by calculating PMV and PPD. This study involved six factors of comfort which is air temperature, average radiant temperature, air velocity, relative humidity, metabolic rate and clothes insulation. Then the study of noise level was conducted by determining LAeq, T, Lmax and Lmin. To carry out this study, Babuc-A equipment were used. The analysis show the area of the manufacturing battery plate having a discomfort condition and PMV result is between 1.5 until 3. Air temperature on the other hand is between 27.4°C-37.8°C while relative humidity is between range 35.35% -92.1% and air velocity 0 m/s-1.28 m/s. Meanwhile the LAeq,T value in the factory is varied from 68 to 80 dB.


2021 ◽  
Vol 881 (1) ◽  
pp. 012029
Author(s):  
H Handri ◽  
L H Sari ◽  
A Munir ◽  
A Ariatsyah

Abstract Pesisir Selatan is one of the districts in West Sumatra with a humid tropical climate with temperatures reaching 32°C during the day. The majority of coastal communities work as fishermen and build houses on the beach, such as in fishermen’s housing in South Painan. In this area there are two models of fisherman housing, namely government-assisted fisherman housing and fisherman’s original housing. Housing on the beachfront will be faced with quite extreme climatic conditions such as air velocity, air temperature, and air humidity which are relatively high on average. Therefore, it is necessary to evaluate the level of thermal comfort in the space in both models of fisherman housing to determine the performance of each fisherman’s housing in dealing with the climate. This study uses a quantitative approach by measuring the parameters of thermal comfort, namely air temperature, humidity and air velocity using a thermohygrometer and anemometer. The data collection method uses descriptive quantitative. Comfort level is evaluated based on the Indonesian national standard (SNI 03-6572-2001) and adaptive thermal comfort. Based on the results of the study, the level of thermal comfort in both models of fisherman housing is classified as uncomfortable according to SNI 03-6572-2001 and adaptive thermal comfort.


2019 ◽  
Vol 10 (1) ◽  
pp. 63-69
Author(s):  
Mária Budiaková

The paper is focused on the influence of air distribution in modern large university lecture hall on the thermal comfort. Providing the optimal parameters of the thermal comfort in the interiors of a university is immensely important for the students. Meeting these parameters is inevitable not only from physiological point of view but also to achieve the desirable students' performance. Parameters of the thermal comfort are also influenced by air distribution system in large university lecture hall. Correct position of supply air and extract air is very important. Experimental measurements of thermal comfort were carried out in the winter season in the large lecture hall of Vienna University of Economics and Business. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, globe temperature, indexes PMV and PPD are presented in the charts. Modern air distribution system and air conditioning system of the large university lecture hall were evaluated on the basis of thermal comfort parameters. Conclusion of this paper states the principles of how to design modern air distribution systems and air conditioning systems in the new large university lecture halls.


2006 ◽  
Author(s):  
A. A. Mozafari ◽  
M. H. Saidi ◽  
J. Neyestani ◽  
A. E. Sany

Investigation of air distribution and wind effect on a vehicle body from the point of view of underhood heat transfer effect and proper positioning of vehicle elements such cooler, condenser and engine configuration is an important area for engine researchers and manufacturers as well. In this research, the effect of air velocity distribution and wind effect around a vehicle is simulated and temperature and velocity distribution around engine block which is influenced by the wind effect is investigated. Thermal investigation of the engine compartment components is performed using results of underhood air temperature and velocity distribution. The heat transfer from engine surface is calculated from the engine energy balance in which their input data are obtained from a comprehensive experimental study on a four cylinder gasoline engine.


2020 ◽  
Vol 2 (1) ◽  
pp. 82
Author(s):  
Agung Prabowo

Abstract -Thermal comfort is a state of mind that expresses satisfaction with the thermal environment. There are two main categories in the effort to obtain a comfort index; empirical and analytical. Empirical is based on social surveys, while analysis is based on the physics principle of heat flow.Bandung city is one of the historical cities in Indonesia which has many historical heritage buidings. One of them which is commonly known as colonial buildings in Bandung is Lautze 2 Mosque, located at Tamblong Street in the city center of Bandung. This research was conducted to analyze the thermal comfort in the Lautze 2 Mosque Bandung. The analytical method used in this study is a quantitative research method by measuring the main factors namely air temperature, air humidity and air velocity. The main factors become obstacles to get thermal comfort data at the Lautze 2 Mosque Bandung is the location of buildings located in areas with tropical climate conditions with high air temperatures, high air humidity, and low air velocitys.The research conclude that thermal comfort in the Lautze 2 Mosque Bandung building can be categorized as uncomfortable, it can be seen from the measurement results of related factors, namely the temperature and humidity that exceeds the comfort limit and the low air velocity in the building becomes an obstacle to obtain thermal comfort. Keywords: colonial buildings, mosque, thermal comfort, tropical climate.


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