scholarly journals Influence of air distribution in modern large university lecture hall on thermal comfort

2019 ◽  
Vol 10 (1) ◽  
pp. 63-69
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Distribution System ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Winter Season ◽  
Point Of View ◽  
Air Distribution ◽  
Lecture Hall ◽  
Globe Temperature ◽  
Air Conditioning Systems

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.

scholarly journals Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang
Keyword(s):  
Thermal Comfort ◽  
Working Conditions ◽  
Distribution System ◽  
Distribution Systems ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Air Distribution ◽  
Large Space ◽  
Air Conditioners ◽  
Air Supply

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.

Evaluation of Indoor Climate in Small University Lecture Hall

2016 ◽  
Vol 861 ◽  
pp. 369-375
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Architectural Design ◽  
Winter Season ◽  
Lecture Hall ◽  
Experimental Measurements ◽  
Optimal Parameters ◽  
Indoor Climate ◽  
Air Velocity ◽  
Globe Temperature ◽  
The University

This paper is focuses on the evaluation of the indoor climate in the small university lecture hall. Providing the optimal parameters of thermal comfort in the interiors of a university is immensely important for the students of the university. Fulfilling these parameters is inevitable not only for the physiological needs of students but also for the required performance of students. Reconstruction took place in the small university lecture hall. The original windows were exchanged for the modern wood tight windows. Experimental measurements were carried out in the winter season in 2016 in this small university lecture hall in order to evaluate the thermal comfort after the reconstruction. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, globe temperature and indexes PMV, PPD are presented in the graphs. Heating, operation and architectural design of the small university lecture hall were evaluated on the basis of the parameters of thermal comfort. In the conclusion of this paper, there are principles how to design new small university lecture halls. Furthermore, there are presented recommendations how to operate the existing small university lecture halls.

Evaluation of Indoor Climate in Big Lecture Hall

2019 ◽  
Vol 887 ◽  
pp. 475-483
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Ventilation System ◽  
Winter Season ◽  
Point Of View ◽  
Lecture Hall ◽  
Experimental Measurements ◽  
Optimal Parameters ◽  
Indoor Climate ◽  
Air Velocity ◽  
Operation System

The paper is oriented on the evaluation of the indoor climate in the big lecture hall. Providing the optimal parameters of the thermal comfort and the CO2 concentration is immensely important for the students in the interiors of a university. Meeting these parameters is inevitable not only from physiological point of view but also for achieving the desirable students' performance. The high CO2 concentration is related to incorrect and insufficient ventilation in the lecture hall and causes distractibility and feeling of tiredness of students. Experimental measurements were carried out in the winter season in 2016 in the big lecture hall in order to evaluate the thermal comfort and the CO2 concentration. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, CO2 concentration are presented in the charts. Mechanical ventilation system and operation system of the big university lecture hall were evaluated on the basis of the parameters of the thermal comfort and on the basis of the CO2 concentration. Based on the findings, design recommendations for new big university lecture halls are derived. Furthermore, there are presented recommendations how to operate the existing big university lecture halls.

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.

Indoor Environment Numerical Simulation of All Cold Air Distribution System With Stratified Air Conditioning

2008 ◽  
Author(s):  
Wei Bing ◽  
Li Li ◽  
Jiang Lu ◽  
Zhang Wei
Keyword(s):  
Numerical Simulation ◽  
Distribution System ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Dew Point ◽  
Air Distribution ◽  
Large Space ◽  
Cold Air ◽  
Point Temperature ◽  
Dew Point Temperature

At present all cold air distribution systems are being used widely due to their advantages of smaller ductwork, shorter floor-to-floor height and less energy consumption etc. They are mostly used in VAV (Variable Air Volume) systems or with the radiant panel systems in the office and residential buildings at the supply air dew point temperature of 6∼10°C, rarely used in large space buildings. The technology of stratified air conditioning is one of the energy saving technologies to large space buildings, which has been popularly used in the conventional air supply systems with the supply air dew point temperature of 11∼16°C. In this paper, the cold air distribution system and the stratified air conditioning technology in a large space building are combined to study. With the method of CFD, the indoor thermal environment of a large space workshop is simulated. The velocity and the temperature as well as the relative humidity fields under different air flow modes are presented, analyzed and compared. With the help of numerical simulation results, the optimal airflow mode is proposed, which show that the all cold air distribution with the stratified air conditioning is a good option for large space buildings. All these above will be good references to the application of cold air distribution system and the selection of the airflow mode in large space buildings.

Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Air Supply ◽  
Air Conditioning Systems ◽  
Air Diffusion

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.

scholarly journals Thermal adaptive behavior and thermal comfort for occupants in multi-person offices with air-conditioning systems

2021 ◽  
pp. 108432
Author(s):  
Peiping Zheng ◽  
Chunxiao Wang ◽  
Yanchen Liu ◽  
Borong Lin ◽  
Huijun Wu ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Adaptive Behavior ◽  
Air Conditioning ◽  
Air Conditioning Systems

scholarly journals Thermal comfort control via air conditioning system using fuzzy neural network feedback controller

2020 ◽  
Vol 19 (2) ◽  
pp. 586
Author(s):  
Somaye A. Mohamadi ◽  
Abdulraheem J. Ahmed
Keyword(s):  
Neural Network ◽  
Thermal Comfort ◽  
Environmental Conditions ◽  
Air Conditioning ◽  
Fuzzy Controller ◽  
Environmental Parameters ◽  
Thermal Conditions ◽  
Real Time Control ◽  
Air Conditioning System ◽  
Air Conditioning Systems

<span>Despite their complexity and uncertainty, air conditioning systems should provide the optimal thermal conditions in a building. These controller systems should be adaptable to changes in environmental parameters. In most air conditioning systems, today, there are On/Off controllers or PID in more advanced types, which, due to different environmental conditions, are not optimal and cannot provide the optimal environmental conditions. Controlling thermal comfort of an air conditioning system requires estimation of thermal comfort index. In this study, fuzzy controller was used to provide thermal comfort in an air conditioning system, and neural network was used to estimate thermal comfort in the feedback path of the controller. Fuzzy controller has a good response given the non-linear features of air conditioning systems. In addition, the neural network makes it possible to use thermal comfort feedback in a real-time control.</span>

scholarly journals Some Aspects of HVAC Design in Energy Renovation of Buildings

2021 ◽  
Author(s):  
Taghi Karimipanah
Keyword(s):  
Renewable Energy ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Energy System ◽  
Building Energy ◽  
Hvac Systems ◽  
Heat Losses ◽  
Energy Sources ◽  
Air Distribution ◽  
Building Energy System

It is well-known fact that air conditioning systems are responsible for a significant part of all energy systems in building energy usage. In EU buildings, the building HVAC systems account for ca 50% of the energy consumed. In the U.S., air-conditioning accounts on average about 12% of residential energy expenditures. The proper choice of air distribution systems and sustainable energy sources to drive the electrical components have a vital impact to achieve the best requirements for indoor climate including, hygienical, thermal, and reasonable energy-saving goals. The building energy system components that have a considerable impact on the demand for final energy in the building are design, outdoor environment conditions, HVAC systems, water consumption, electrical appliances, indoor thermal comfort, and indoor human activities. For calculation of the energy balance in a building, we need to consider the total energy flows in and out from the building including ventilation heat losses, the perimeters transmission heat loses, solar radiation, internal heat from occupants and appliances, space and domestic water heating, air leakage, and sewage heat losses. However, it is a difficult task to handle the above time-dependent parameters therefore an energy simulation program will always be used. This chapter aims to assess the role of ventilation and air-conditioning of buildings through the sustainability approaches and some of the existing renewable energy-based methods of HVAC systems are presented. This comprehensive review has been shown that using the new air distribution systems in combination with renewable energy sources are key factors to improve the HVAC performance and move toward Nearly Zero Carbon Buildings (NZCB).

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