A Study on the Improvement of ADPI and Ventilation Effectiveness in a Small Theater

2016 ◽  
Vol 24 (03) ◽  
pp. 1650019
Author(s):  
Yong-Il Kwon
Keyword(s):  
Distribution System ◽  
Volume Flow Rate ◽  
Ventilation System ◽  
Air Distribution ◽  
Air Exchange Rate ◽  
Downward Displacement ◽  
Upward Displacement ◽  
Ventilation Effectiveness ◽  
Displacement System ◽  
Selection Of

In the air distribution design of a small theater, either a downward or an upward displacement ventilation is applied generally. The cool air is supplied from openings distributed over the ceiling and extracted beneath the seats for the downward flow and supplied from beneath the seats and extracted from the ceiling for the upward flow system. By the change of air exchange rate (ACH) produced by two divergent ventilation systems inside theater, thermal comfort and ventilation effectiveness around the seats show a different phenomenon. Thereby, it can be seen that the selection of the ventilation system is a significant factor in energy saving. CFD calculations for this study were performed to investigate the effects of various parameters (ADPI and ACE) of air distribution system applied in order to save the cooling energy. This paper focuses mainly on the effect of the varied volume flow rate depending on the ventilation system. The ventilation performances of the downward displacement system are compared quantitatively with the upward displacement system using the concept of the LMA of fresh air.

scholarly journals Operation Testing of an Advanced Personalized Ventilation System

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1596 ◽  
Author(s):  
Csáky ◽  
Kalmár ◽  
Kalmár
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Distribution System ◽  
Noise Level ◽  
Background Noise ◽  
Ventilation System ◽  
Air Distribution ◽  
Personalized Ventilation

Using personalized ventilation systems in office buildings, important energy saving might be obtained, which may improve the indoor air quality and thermal comfort sensation of occupants at the same time. In this paper, the operation testing results of an advanced personalized ventilation system are presented. Eleven different air terminal devices were analyzed. Based on the obtained air velocities and turbulence intensities, one was chosen to perform thermal comfort experiments with subjects. It was shown that, in the case of elevated indoor temperatures, the thermal comfort sensation can be improved considerably. A series of measurements were carried out in order to determine the background noise level and the noise generated by the personalized ventilation system. It was shown that further developments of the air distribution system are needed.

scholarly journals Ventilation of engine rooms in diesel engines ships

2020 ◽  
Vol 43 ◽  
pp. 69-78
Author(s):  
Victor Mihai ◽  
Liliana Rusu ◽  
Adrian Presura
Keyword(s):  
Pressure Drop ◽  
Diesel Engines ◽  
Distribution System ◽  
High Efficiency ◽  
Ventilation System ◽  
Air Distribution ◽  
Cooling Air ◽  
Principal Design

"Engines room are equipped with a ventilation system which should provide fresh air for combustion and for removing the heat radiated by main engines, auxiliary engines, boilers, generators and other hot equipment installed in compartment. The paper presents the main requirements, recommendations and challenges regarding designing and construction of the ventilation system. The principal design aspects highlighted in this material are related to reducing the pressure drop across the distribution system to reduce the energy used by the fan to blow the air inside the room and to identify the best arrangement of air distribution inlet/outlet in order to get high efficiency of the cooling air."

Energy Use Comparison of Air Distribution Systems Serving a Section of a School Building

2012 ◽  
Author(s):  
Stillman Jordan ◽  
Randall D. Manteufel
Keyword(s):  
Total Energy ◽  
Distribution System ◽  
Energy Recovery ◽  
Distribution Systems ◽  
Energy Savings ◽  
Ventilation System ◽  
Space Distribution ◽  
Air Distribution ◽  
Displacement Ventilation ◽  
Humid Climate

An optimal air distribution design accomplishes both comfort and ventilation requirements while consuming as little energy as possible. This paper analyzes four different air distribution systems and technologies including single duct variable air volume air handlers, chilled beam cooling systems, total energy recovery wheels, displacement ventilation, and dedicated outside air systems; in an effort to determine the best air distribution system for a representative section of a school in hot and humid climate. The effectiveness of the air distribution systems is evaluated by analyzing how the different technologies take advantage of the natural convective properties of air to create a comfortable environment for the occupied region of the space. Distribution effectiveness and energy consumption must be weighed against considerations such as system complexity and ease of operation. This paper compares several alternative air distribution systems to a baseline single inlet VAV system that is commonly used in new schools designed today. Calculations show that the total energy recovery wheels result in a 16% energy savings over the baseline air distribution system because of the large amount of outside air required in school buildings. Chilled beams are not well suited for schools because of the large amount of outside air required by the space and the sophisticated design and operation needed to prevent condensation from occurring at the chilled beam. The results show that the air distribution system that consumes the least amount of energy is a displacement ventilation system. The system also inherently promotes better indoor air quality as it allows air to naturally rise out and return out of the space with minimal mixing of contaminates that may be recirculated within the room for others to breath. The displacement ventilation system’s overall energy savings of 20% over the baseline is mainly attributed to its total energy recovery wheel and the system’s ability to drastically reduce the cooling load seen by the air cooled chiller by effectively ventilating spaces using less outside air.

scholarly journals A Numerical Analysis of the Air Distribution System for the Ventilation of the Crew Quarters on board of the International Space Station

2018 ◽  
Vol 32 ◽  
pp. 01006 ◽  
Author(s):  
Florin Bode ◽  
Ilinca Nastase ◽  
Cristiana Verona Croitoru ◽  
Mihnea Sandu ◽  
Angel Dogeanu
Keyword(s):  
International Space Station ◽  
Distribution System ◽  
Ventilation System ◽  
Space Station ◽  
Personal Space ◽  
Air Distribution ◽  
Breathing Zone ◽  
Noise Levels ◽  
Lower Velocity ◽  
International Space

Quality of life on the International Space Station (ISS) has become more and more important, since the time spent by astronauts outside the terrestrial atmosphere has increased in the last years. The actual concept for the Crew Quarters (CQ) have demonstrated the possibility of a personal space for sleep and free time activities in which the noise levels are lower, but not enough, compared to the noisy ISS isle way. However, there are several issues that needs to be improved to increase the performance of CQ. Our project QUEST is intended to propose a new concept of CQ in which we will correct these issues, like the noise levels will be lower, more space for astronaut, increased thermal comfort, reduce the CQ total weight, higher efficiency for the air distribution, personalized ventilation system in CQ for the crew members in order to remove CO2 from the breathing zone. This paper presents a CFD study in which we are comparing the actual and a proposed ventilation solution for introducing the air in CQ. A preliminary numerical model of the present configuration of the air distribution system of the Crew Quarters on board of the ISS, shows the need for an improved air distribution inside these enclosures. Lower velocity values at the inlet diffuser, distributed over a larger surface, as well as diffusers with improved induction would appear to be a better choice. This was confirmed through the development of a new model including linear diffusers with a larger discharge surface. In this new configuration, the regions of possible draught are dramatically reduced. The overall distributions of the velocity magnitudes displaying more uniform, lower values, in the same time with more uniform temperatures. All these observations allow us to consider a better mixing of the air inside the enclosure.

A Study on Thermal Characteristics Affected by Air Distribution System Installed in Indoor Ice Rink Arena

2019 ◽  
Vol 27 (01) ◽  
pp. 1950007 ◽  
Author(s):  
Yong-Il Kwon
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Thermal Environment ◽  
Ventilation System ◽  
Thermal Characteristics ◽  
Heating System ◽  
Air Distribution ◽  
Winter Olympics ◽  
Ice Surface ◽  
The Republic

The Republic of Korea held the Winter Olympics in February 2018 and built several indoor ice rinks. Recently, the population of viewing and enjoying winter sports in indoor ice rink arenas is increasing and it is expected that the demand for building new indoor ice rink arenas will increase in the future. These indoor ice rinks generally should have an adequate dehumidification and heating system to provide optimal indoor air condition for users (spectators and athletes) under the required heat and humidity conditions. In addition, HVAC system designers should take steps to prevent fogging from condensation on the ice surface and to prevent condensation on the walls. This study was carried out to evaluate the formation of fog near the ice surface by using two air distribution systems applicable to the indoor ice rink arena. It was confirmed that the mixed ventilation method did not cause fog near ice surface, and that there is a great difference in the composition of the indoor thermal environment of the ice rink arena according to the type of ventilation system.

scholarly journals Experimental Investigation of the Ventilation Performance of Different Air Distribution Systems in an Office Environment—Cooling Mode

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1354 ◽  
Author(s):  
Arman Ameen ◽  
Mathias Cehlin ◽  
Ulf Larsson ◽  
Taghi Karimipanah
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Ventilation System ◽  
Impinging Jet ◽  
Air Distribution ◽  
Displacement Ventilation ◽  
Cooling Mode ◽  
Distribution Method ◽  
Ventilation Performance ◽  
Velocity Turbulence

The performance of a newly designed corner impinging jet air distribution method with an equilateral triangle cross section was evaluated experimentally and compared to that of two more traditional methods (mixing and displacement ventilation). At nine evenly chosen positions with four standard vertical points, air velocity, turbulence intensity, temperature, and tracer gas decay measurements were conducted for all systems. The results show that the new method behaves as a displacement ventilation system, with high air change effectiveness and stratified flow pattern and temperature field. Both local air change effectiveness and air exchange effectiveness of the corner impinging jet showed high quality and promising results, which is a good indicator of ventilation effectiveness. The results also indicate that there is a possibility to slightly lower the airflow rates for the new air distribution system, while still meeting the requirements for thermal comfort and indoor air quality, thereby reducing fan energy usage. The draught rate was also lower for corner impinging jet compared to the other tested air distribution methods. The findings of this research show that the corner impinging jet method can be used for office ventilation.

scholarly journals Evaluating the cooling capacity of diffuse ceiling ventilation system – Full-scale experimental study

2019 ◽  
Vol 111 ◽  
pp. 02006 ◽  
Author(s):  
Samira Rahnama ◽  
Peter Vilhelm Nielsen ◽  
Alireza Afshari ◽  
Niels Christian Bergsøe ◽  
Hicham Johra ◽  
...  
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Ventilation System ◽  
Cooling Capacity ◽  
Full Scale ◽  
Air Distribution ◽  
Controlled Environment ◽  
Airflow Rate ◽  
Heat Sources ◽  
Partial Coverage

Diffuse ceiling ventilation system is an air distribution system in which part of the suspended ceiling made of perforated panels is used as an air diffuser for the supply of fresh air. This method has been proven to have a higher cooling capacity compared to conventional air distribution systems. The cooling capacity of the system, however, depends on several parameters. This paper presents evaluation results regarding the cooling capacity of the diffuse ceiling ventilation system in connection to two essential parameters, i.e. the distribution of heat sources in the room and the ratio of perforated to non-perforated panels in the ceiling. The evaluation is based on full-scale experiments performed in a laboratory controlled environment and using a design chart which expresses the limits on the supply airflow rate and temperature. The experimental results indicate that the highest cooling capacity is achieved when the heat sources are distributed evenly and the perforated panels cover the entire ceiling. In the case of partial coverage, the cooling capacity is reduced when the heat sources are placed below the perforated panels. The system can have a higher cooling capacity in the partial coverage configuration compared to the full coverage one depending on the supply airflow rate.

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