A methodology to measure the rates of air infiltration into refrigerated compartments

2019 ◽  
Vol 97 ◽  
pp. 88-96 ◽  
Author(s):  
Paula do Vale Pereira ◽  
Cláudio Melo
Keyword(s):  
2021 ◽  
Vol 13 (12) ◽  
pp. 6875
Author(s):  
Irene Poza-Casado ◽  
Raquel Gil-Valverde ◽  
Alberto Meiss ◽  
Miguel Ángel Padilla-Marcos

Indoor air quality (IAQ) in educational buildings is a key element of the students’ well-being and academic performance. Window-opening behavior and air infiltration, generally used as the sole ventilation sources in existing educational buildings, often lead to unhealthy levels of indoor pollutants and energy waste. This paper evaluates the conditions of natural ventilation in classrooms in order to study how climate conditions affect energy waste. For that purpose, the impact of the air infiltration both on the IAQ and on the efficiency of the ventilation was evaluated in two university classrooms with natural ventilation in the Continental area of Spain. The research methodology was based on site sensors to analyze IAQ parameters such as CO2, Total Volatile Organic Compounds (TVOC), Particulate Matter (PM), and other climate parameters for a week during the cold season. Airtightness was then assessed within the classrooms and the close built environment by means of pressurization tests, and infiltration rates were estimated. The obtained results were used to set up a Computational Fluid Dynamics (CFD) model to evaluate the age of the local air and the ventilation efficiency value. The results revealed that ventilation cannot rely only on air infiltration, and, therefore, specific controlled ventilation strategies should be implemented to improve IAQ and to avoid excessive energy loss.


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

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7537
Author(s):  
Piotr Lis ◽  
Anna Lis

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.


Author(s):  
Rabbani Rasha ◽  
M. Tariq Iqbal

This paper represents an energy consumption and heat loss analysis of a heat recovery ventilator unit in a single-family detached house in St. John’s, NL, Canada. An energy-efficient house is a growing attraction to control the air infiltration, provide a comfortable environment with reduced yearly electricity cost. A mechanical induced ventilation system is inevitable to increase energy efficiency and to reduce greenhouse gas emissions of the house in order to supply fresh air. A heat recovery ventilator (HRV) is an air to air heat exchangers that recovers heat from inside of the house and delivers this preheated and fresh air to the space for maintaining the occupant’s comfort. In this paper, yearly energy consumption with the heat loss of a typical heat recovery ventilator unit is presented. MATLAB, BE opt, and Microsoft Excel are used to do all necessary simulation with calculation using one-year logged data. Methodology, results with graphs and detailed analysis of this research are included in this paper. This research indicates that the cost of running a HRV for a year in a house in St. John’s could be as high as $484 per year with an unknown air quality improvement.


2008 ◽  
pp. 185-185-10
Author(s):  
HR Trechsel ◽  
DT Harrje
Keyword(s):  

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