Associations of Indoor Carbon Dioxide Concentration and Symptoms of Sick Building Syndrome in Air-Conditioned Lecture Halls

Jayasooriya, Varuni; Rajapaksha, R M D H; Ng, A.; Muthukumaran, Shobha

doi:10.21203/rs.3.rs-95698/v1

Cited by 2 publications

(2 citation statements)

References 41 publications

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“…This problem attracted significant attention already in the 1990s, in particular in office buildings [53,54]. In recent years, factors that contribute to the SBS were also explored in residential buildings [55,56], schools [57] and lecture halls [58]. Symptoms of SBS have been more frequently reported in air-conditioned than in naturally ventilated premises.…”

Section: Mechanical Ventilationmentioning

confidence: 99%

The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

Skotnicka-Siepsiak

2020

Energies

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Energy-saving ventilation systems are designed to improve the energy efficiency of buildings. Low energy efficiency in buildings poses a considerable problem that needs to be addressed. Mechanical ventilation with heat recovery has gained increased popularity in recent years. Mechanical ventilation has numerous advantages, including easy adjustment and control, high indoor air quality and elimination of indoor pollutants. Mixing ventilation is the most popular type of mechanical ventilation, in particular in residential buildings. Unsteady ventilation is a type of mixing ventilation that involves stronger mixing effects and smaller vertical temperature gradients to improve indoor air quality (IAQ) and minimize energy consumption. This study examines the possibility of controlling and modifying Coanda effect hysteresis (CEH) to generate unsteady flow and simulate the conditions of unsteady mixing ventilation. The experiment was performed on a self-designed test bench at the University of Warmia and Mazury in Olsztyn. It demonstrated that an auxiliary nozzle can be applied at the diffuser outlet to control CEH and the angles at which the air jet becomes attached to and separated from the flat plate positioned directly behind the nozzle. The study proposes an innovative mixing ventilation system that relies on CEH. The potential of the discussed concept has not been recognized or deployed in practice to date. This is the first study to confirm that an auxiliary nozzle by the diffuser outlet can be operated in both injection and suction mode to control CEH. In the future, the results can be used to design a new type of nozzles for unsteady ventilation systems that are based on CEH control.

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Section: Mechanical Ventilationmentioning

confidence: 99%

The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

Skotnicka-Siepsiak

2020

Energies

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“…The indicator most frequently used to represent air quality in rooms occupied by people is the concentration of CO 2 e.g., [14][15][16][17][18]. Carbon dioxide is a major, but not the only type, of indoor air contamination.…”

Section: Introductionmentioning

confidence: 99%

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

Lis

2021

Energies

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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.

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Associations of Indoor Carbon Dioxide Concentration and Symptoms of Sick Building Syndrome in Air-Conditioned Lecture Halls

Cited by 2 publications

References 41 publications

The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

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

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