Outdoor air supply in winter for large-space airport terminals: Air infiltration vs. mechanical ventilation

2021 ◽  
Vol 190 ◽  
pp. 107545
Author(s):  
Xiaochen Liu ◽  
Tao Zhang ◽  
Xiaohua Liu ◽  
Yi Jiang
Keyword(s):  
Mechanical Ventilation ◽  
Outdoor Air ◽  
Large Space ◽  
Air Infiltration ◽  
Air Supply ◽  
Airport Terminals

scholarly journals Research on Air Infiltration Characteristics of High-speed Railway Station

2021 ◽  
Vol 261 ◽  
pp. 03041
Author(s):  
Qian Bin ◽  
Sun Liangliang ◽  
Yu Tao ◽  
Lei Bo ◽  
Bi Haiquan
Keyword(s):  
Mechanical Ventilation ◽  
High Speed ◽  
Thermal Environment ◽  
Dominant Role ◽  
Ventilation System ◽  
Large Space ◽  
Railway Station ◽  
High Speed Railway ◽  
Air Infiltration ◽  
Air Volume

High-speed railway station has a large space and a large amount of air infiltration, which has great influences on the thermal load, the thermal environment and the air quality. In this paper, the air infiltration and its distribution characteristics in winter and summer in different climatic zones are determined by CO2 concentration method. The results showed that buoyancy-driven pressure played a dominant role, and the infiltration air volume of 2.8 h-1 in winter is larger than that of 2.0 h-1 in summer. The infiltration air volume in the hot summer and cold winter zone and the hot summer and warm winter zone is larger than that in the cold zone. When the mechanical ventilation system for fresh air is turned off, the indoor CO2 concentration meets the human safety threshold. But it can be found that when the air infiltration volume is small enough to a certain extent, the air infiltration volume has a poor dilutive effect on pollutants in the deeper parts of the station. The tradeoff between the utilization of air infiltration and the elimination of mechanical ventilation needs to be furthered considered.

On-site measurement of winter indoor environment and air infiltration in an airport terminal

2018 ◽  
Vol 28 (4) ◽  
pp. 564-578 ◽  
Author(s):  
Xiaochen Liu ◽  
Xiaohua Liu ◽  
Tao Zhang ◽  
Bowen Guan
Keyword(s):  
Energy Consumption ◽  
Thermal Environment ◽  
Space Heating ◽  
Large Space ◽  
Heating Systems ◽  
Indoor Thermal Environment ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Airport Terminal ◽  
Airport Terminals

Currently, many airports in China are being built or retrofitted. Reducing energy consumption in airport terminals is of the utmost urgency. This paper describes on-site measurements of indoor thermal environment and air infiltration of a hub airport in winter in southwest China. Air velocity measurements with air volume balance check and thermal balance check were applied to assess air infiltration rates in terminal buildings. In unsecured halls, air infiltration rates were 0.61 air change per hour (ACH) (6.6 m3/(h m2)) and 0.28 ACH (3.0 m3/(h m2)) when space heating was on and off, respectively; while in secured piers, those two air infiltration rates were 0.42 ACH (2.6 m3/(h m2)) and 0.24 ACH (1.5 m3/(h m2)). Air infiltration consumed 66–92% of heat supplied by space heating systems, showing that winter air infiltration significantly affects indoor thermal environment and energy consumption in terminal buildings where air flows out through the doors of service walkways and open skylights on the roof. Furthermore, influences of building characteristics, space heating systems and outdoor temperatures on winter air infiltration in large space buildings were analysed. This research helps to clarify the key issues influencing indoor thermal environment and proposes solutions for energy saving in terminal buildings.

Winter air infiltration induced by combined buoyancy and wind forces in large-space buildings

2021 ◽  
Vol 210 ◽  
pp. 104501
Author(s):  
Xiaochen Liu ◽  
Xiaohua Liu ◽  
Tao Zhang ◽  
Chao Lin ◽  
Huai-Yu Zhong ◽  
...  
Keyword(s):  
Large Space ◽  
Air Infiltration

scholarly journals The Required Amount of Ventilation Air for the Classroom and the Possibility of Air Infiltration through the Windows

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7537
Author(s):  
Piotr Lis ◽  
Anna Lis
Keyword(s):  
Mechanical Ventilation ◽  
Urban Population ◽  
Heat Recovery ◽  
Main Issue ◽  
School Buildings ◽  
Air Leakage ◽  
Air Infiltration ◽  
Technical Requirements ◽  
Leakage Coefficient

The majority of education buildings in Poland are equipped with natural (gravity) ventilation, where the air inflow depends on the level of window airtightness. A complete statistical urban population of 50 school buildings in Czestochowa have been examined. The main issue to be clarified is the answer to the following questions: Is it theoretically possible to supply enough air to meet the ventilation requirements with gravity ventilation? What is the airtightness of the windows at which it will be possible? The average technical conditions of windows in the analysed buildings were bad. However, only in the case in which high external air leakage coefficient a = 7.0 m3/(h m daPa2/3) (q100KL = 32.4912 m3/(h m) is the amount of air passing through the leaks similar to the quantitative ventilation requirements for classrooms. The quantity of air flowing from the outside through modernized windows that meet the technical requirements (a = 0.6 to 1.0 m3/(m h daPa2/3)) covers on average only about 12% and about 21% of the ventilation needs. Without installing additional vents in the rooms, or better yet, installing mechanical ventilation with heat recovery, meeting the ventilation norm requirements will be impossible.

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.

Heat transfer between occupied and unoccupied zone in large space building with floor-level side wall air-supply system

2020 ◽  
Vol 13 (6) ◽  
pp. 1221-1233
Author(s):  
Xinqi Yang ◽  
Haidong Wang ◽  
Chunxiao Su ◽  
Xin Wang ◽  
Yi Wang
Keyword(s):  
Heat Transfer ◽  
Side Wall ◽  
Supply System ◽  
Large Space ◽  
Floor Level ◽  
Air Supply

Numerical investigation of radon dispersion and dose assessment for typical ventilation schemes with an air purifier

2020 ◽  
Vol 30 (1) ◽  
pp. 114-128
Author(s):  
Dong Xie ◽  
Chenhua Wang ◽  
Chuck W Yu ◽  
Hanqing Wang
Keyword(s):  
Mechanical Ventilation ◽  
Effective Dose ◽  
Natural Ventilation ◽  
Indoor Radon ◽  
Radioactive Decay ◽  
Dose Assessment ◽  
Radiological Protection ◽  
Ventilation Condition ◽  
Air Supply ◽  
Air Purifier

Radon is a radioactive pollutant that could pose hazards to the surrounding environment and people due to its radioactive decay progenies. In this study, numerical simulations of radon dispersion were conducted under natural and mechanical ventilation with an air-purifier for radon. Factors such as the air supply speed, position and air supply angles of the purifier were considered. Results showed that the increase in the air supply speed from the purifier was an effective solution to reduce indoor radon pollution. The effect was better when the purifier was in the middle of the room. The purification effect was similar when the air supply changed under natural ventilation, while purification function was more effective when the air supply angle was 60° under the mechanical ventilation condition. An effective dose estimation involving typical ventilation schemes with radon purifier was evaluated. Using this approach, the radiation effect on occupants was computed. The calculated effective dose was 0.9 mSv y−1 when the air supply speed of the purifier was 0.2 m s−1 under natural ventilation. As a result, the effective dose calculated was under the annual effective dose limit of 3–10 mSv y−1 recommended by the International Commission on Radiological Protection (ICRP) for public exposure.

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