scholarly journals Effect of mechanical ventilation on air infiltration rate in a concert hall

2019 ◽  
Vol 609 ◽  
pp. 032015
Author(s):  
Yuchen Shi ◽  
Xiaofeng Li
Keyword(s):  
Mechanical Ventilation ◽  
Infiltration Rate ◽  
Concert Hall ◽  
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 Swine Finishing Room Air Infiltration: Part 1. Quantification and Prediction

2018 ◽  
Vol 34 (2) ◽  
pp. 413-424
Author(s):  
H T Jadhav ◽  
S J Hoff ◽  
J D Harmon ◽  
Igancio Alvarez ◽  
D S Andersen ◽  
...  
Keyword(s):  
Sea Level ◽  
Power Law ◽  
Pressure Difference ◽  
Construction Material ◽  
Weather Conditions ◽  
Infiltration Rate ◽  
Mechanically Ventilated ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Single Room

Abstract. Air infiltration through unplanned inlets is an integral component of any ventilation process. Air infiltration affects the quality of the room environment and can also increase winter heating costs. Precise data on air infiltration is very important in the design of animal room ventilation systems. Nineteen mechanically ventilated (negative pressure type) swine finishing rooms in Iowa were tested for their air infiltration potential. Using the data of 17 rooms, air infiltration rate through the whole room (i.e., total air infiltration, It), curtains (Ic), fans (If), and net building shell (other components, Io) were quantified. Power law equations were developed for infiltration prediction of different room configurations grouped on the basis of their construction style, age, ceiling material, curtain perimeter, and fan backdraft shutter area. All power law models reported in this study were adjusted to predict standard (sea level) infiltration rates. At 20 Pa pressure difference across the room envelope, the predicted standard It infiltration rate for the 17 rooms was 5.96±1.49 air changes per hour (ach); whereas, the predicted standard Ic, If, and Io infiltration rates were 1.49 ±1.00 ach (about 25% of It), 1.52 ±1.38 ach (about 26% of It) and 2.90 ±1.42 ach (about 49% of It), respectively. The standard It infiltration rate trended lower for rooms (n=8) from single room layout barns (5.85 ±1.66 at 20 Pa), rooms (n=8) having a non-metal ceiling (5.85 ±2.15 at 20 Pa), and rooms (n=8) aged = 13 years (5.85 ±2.15 at 20 Pa). The infiltration resistances, calculated using standard sea level infiltration rates, indicated that the curtain, fan, and other infiltration areas of swine finishing rooms changes with barn layout, age, construction material, and pressure difference. Methodology to convert measured infiltration rates to standard sea level weather conditions and to any desired room location was included. Keywords: Infiltration, Swine finishing Barns, Swine finishing rooms, Infiltration prediction, Infiltration quantification, Ventilation.

Estimation of appropriate capacity of ventilation system based on the air infiltration rate in Korean classrooms

2008 ◽  
Vol 22 (4) ◽  
pp. 788-797 ◽  
Author(s):  
Jonghoon Park ◽  
Yongsung Jang ◽  
Youngchull Ahn ◽  
Seongir Cheong ◽  
Jaekeun Lee
Keyword(s):  
Ventilation System ◽  
Infiltration Rate ◽  
Air Infiltration

scholarly journals Evaluating methods for estimating whole house air infiltration rates in summer: implications for overheating and indoor air quality

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ben M. Roberts ◽  
David Allinson ◽  
Kevin J. Lomas
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Infiltration Rate ◽  
Estimation Methods ◽  
Tracer Gas ◽  
Content Type ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Fan Pressurisation

PurposeAccurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.Design/methodology/approachFifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.FindingsThe eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.Practical implicationsThe findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.Originality/valueDirect measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

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.

A new PM2.5-based CADR method to measure air infiltration rate of buildings

2020 ◽  
Author(s):  
Cong Liu ◽  
Siyu Ji ◽  
Fengjiao Zhou ◽  
Qingbin Lin ◽  
Yiqi Chen ◽  
...  
Keyword(s):  
Infiltration Rate ◽  
Air Infiltration
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