Ventilation Systems
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Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 408
Author(s):  
Aneta Grodzicka ◽  
Franciszek Plewa ◽  
Marcin Krause ◽  
Andrzej Figiel ◽  
Magdalena Rozmus

The way in which rescue actions are carried out in a hard coal mine is conditioned by a number of factors, including the type, scale, and location of the hazard; location of employees at the danger and level of their endangerment; and the ventilation system used in the impacted area. In this article, the importance and necessity to take into account a human factor, specifically the propensity for risky behavior, alongside the selection of rescuers for rescue action is pointed out. As an introduction to the key research studies presented in this article, main ventilation systems used in hard coal mines are described and three real cases of natural hazard occurrences in hard coal mines are discussed. An analysis of these events has shown that the degree of difficulty of a rescue action depends, among other aspects, on the ventilation system applied. Next, a study covering a synthetic assessment of 25 mining rescuers taking into account the ‘risky behavior’ parameter is presented. The results were interpreted considering the—described earlier—cases of hazard occurrence in coal mines and ventilation systems applied there. For the research sample, a selection of rescuers to carry out actions in particular types of ventilation systems, taking as a criterion the mark they obtained in the synthetic assessment, is proposed.


Author(s):  
Farhad Forouharmajd ◽  
Shiva Soury ◽  
Mehran Mokhtari ◽  
Zahra Mohammadi

Background and purpose: Vibration caused by ventilation systems in buildings is one of the harmful physical factors that can cause harm to residents. Therefore, measuring and controlling vibration is important. Materials and Methods: In the first step of the study, the vibration accelerometer was placed on the base of a fan where the vibrations were sent toward the duct wall. A vibration assessment of the building was conducted in the other steps to compare with guidelines. In the next step, isolation method was used to control vibration. By placing the isolator on the duct wall, the accelerometer was located on the body of the duct wall and the value of vibration was measured in a millimeter per second. All stages of the experiment were performed in the Faculty of Health of Isfahan University of Medical Sciences in 2018. Results: The maximum vibration velocity reduction in the building was related to the frequency of 68 Hz, which reached 33 mm/s after isolation. In addition, the fan vibration at 485 Hz was equal to 2.1 m /s, which decreased to 2 mm /s after isolation. Conclusion: Comparison of vibration after fan isolation with standard showed that this method has been effective in reducing the fan vibration resulting in the vibration to reach below the standard.


2022 ◽  
Vol 354 ◽  
pp. 00030
Author(s):  
Florin Rădoi ◽  
Ion Gherghe ◽  
Alexandru Cămărășescu

The activity of evaluation and verification of industrial ventilation installations has a strong preventive role in terms of explosion risk mainly due to the fact that of the three determining elements that can lead to an explosion phenomenon, ventilation installations can determine the presence of two elements namely the presence of fuel (gases, vapours, dusts, mists) and the source of initiation (hot surface, flame, sparks of mechanical origin, electrical sparks, static electricity, etc.). The development of experimental systems on„ which particular hazardous aspects that may occur during the operation of industrial ventilation systems can be studied are vital to avoid dangerous situations in the current operation of ventilation installations. Knowledge of the dynamics of formation of explosive / toxic / asphyxiating environments is achieved by analysing explosive mixtures in relation to specific explosive intervals and is one of the most important priorities in ensuring optimal health and safety at work in industrial activities. The information obtained by analysing the dynamics of the formation of explosive / toxic / asphyxiating atmospheres is extremely useful for personnel responsible for health and safety at work, because with their help relevant decisions can be made to ensure safety and health conditions at the level of industrial premises. The paper presents an experimental equipment usable for the study of industrial ventilation systems.


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 220
Author(s):  
Yeo-Kyung Lee ◽  
Young Il Kim

Owing to the recent increase in the number of warning reports and alerts on the dangers of fine dusts, there has been an increasing concern over fine dusts among citizens. In spaces with poor ventilation, the occupants are forced to open the window to initiate natural ventilation via the direct introduction of the outside air; however, this may pose a serious challenge if the external fine-dust concentration is high. The lack of natural ventilation increases the indoor carbon dioxide (CO2) concentration, thus necessitating the installation of mechanical ventilation systems. This study analyzed the frequency of the application of mechanical ventilation systems in the Multi-purpose activity space of elementary schools, which are spaces where children require a higher indoor air quality than adults owing to the rapid increase in the CO2 concentration of the Multi-purpose activity space during activities. In addition, the architectural and equipment factors of the Multi-purpose activity spaces of nine elementary schools were characterized. The results revealed that five out of the nine elementary schools installed mechanical ventilation systems, whereas the remaining four schools installed jet air turnover systems. The indoor air quality of the Multi-purpose activity space of D elementary school, which had the minimum facility volume among the schools investigated in this study (564.2 m3), with up to 32 participants for each activity, was investigated. The results revealed that the ultrafine-dust (PM2.5) concentration of the facility was as high as 4.75 µg/m3 at a height of 1.2 m, and the CO2 concentration was as high as 3183 ppm. The results of the analysis of three elementary schools with different volumes were compared and analyzed using CONTAM simulation. This study determined the required volume per occupant and the optimum number of occupants for a given volume and presented guidelines for the optimum number of occupants, activities, and volume to reduce the high concentration of pollutants in the analyzed Multi-purpose activity space. The guideline proposed in this study is aimed at maintaining the CO2 concentration of the Multi-purpose activity space below 1000 ppm, as prescribed by the Indoor Air Quality Control in Public-Use Facilities, Etc. Act in South Korea.


2021 ◽  
Vol 6 (4) ◽  
pp. 251-263
Author(s):  
Nangkula Utaberta ◽  
Hayder Jawwad Shakir

Mosques are places where Muslims perform prayers and other social activities. Those are built as a place for humans to worship the Almighty Allah at all times, as well as to provide an environment that responds to the needs of devotees and educates the future generation by the Quranic verses and the Prophet's teachings. Derived from the Holy Quran and the Prophet, purity is compulsory at all times for Muslims, and has many meanings that are applicable during prayers and the day. The ablution room is integrated into all mosque designs because it is an unseparated element. However, Malaysian mosques have been questioned in their application of some Islamic regulations to uniform a hygienically clean space that can respond the needs of Muslims. The design of the ablution rooms in Malaysian mosques is encountering a serious issue regarding the spaces' cleanliness. Although the ablution room has been designed to respond the Muslim's need to conduct the ablution practice and to cleanse a person spiritually and physically, several problems related to its design aspects were revealed. This research investigates the cleanliness of the Malaysian ablution space. It examines how the design aspects of the ablution rooms of the Iconic Malaysian Mosques impact the area's cleanliness and its users. Five case studies were selected for this study. Three methods of study were utilized: physical observation, architectural drawing analysis, and interviews. Aspects of design form, ventilation, cleaning status, and user experience were discussed. This research suggested that the larger mosques in Malaysia were suffering from serious hygiene issues that resulted from many aspects, including poor design, ventilation systems, and users' abuse. The research suggested some design guidelines for future and existing ablution areas that will improve the cleanliness.


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 98
Author(s):  
Effrosyni Giama

Buildings are responsible for approximately 30–40% of energy consumption in Europe, and this is a fact. Along with this fact is also evident the existence of a defined and strict legislation framework regarding energy efficiency, decarbonization, sustainability, and renewable energy systems in building applications. Moreover, information and communication technologies, along with smart metering for efficient monitoring, has come to cooperate with a building’s systems (smart buildings) to aim for more advanced and efficient energy management. Furthermore, the well-being in buildings still remains a crucial issue, especially nowadays that health and air quality are top priority goals for occupants. Taking all the above into consideration, this paper aims to analyze ventilation technologies in relation to energy consumption and environmental impact assessment using the life cycle approach. Based on the review analysis of the existing ventilation technologies, the emphasis is given to parameters related to the efficient technical design of ventilation systems and their adequate maintenance under the defined guidelines and standards of mechanical ventilation operation. These criteria can be the answer to the complicated issue of energy efficiency along with indoor air quality targets. The ventilation systems are presented in cooperation with heating and cooling system operations and renewable energy system applications ensuring an energy upgrade and reduced greenhouse gas emissions. Finally, the mechanical ventilation is examined in a non-residential building in Greece. The system is compared with the conventional construction typology of the building and in cooperation with PVs installation in terms of the environmental impact assessment and energy efficiency. The methodology implemented for the environmental evaluation is the Life Cycle Analysis supported by OpenLca software.


Author(s):  
Дмитрий Валерьевич Лобанов ◽  
Игорь Иванович Звенигородский ◽  
Александр Александрович Мерщиев ◽  
Роман Александрович Шепс

Умственный труд достаточно разнообразен и характеризуется различной степенью ответственности, монотонности, внимания, уровнем эмоционального напряжения. Для обеспечения комфортных условий пребывания человека на постоянном рабочем месте, необходимо в том числе организовывать системы климатизации. Наиболее перспективными для указанной деятельности, являются персональные системы вентиляции, обеспечивающие качественную воздушную среду в зоне дыхания человека при одновременном снижении капитальных и эксплуатационных затрат по сравнению с традиционными видами систем вентиляции (смешивающая, вытесняющая вентиляция). Однако, при проектировании таких систем следует ориентироваться не на «среднего условного человека», а учитывать индивидуальные особенности работника (возраст, пол и др.), выполняющего конкретный вид умственной деятельности. С целью уточнения фактической величины углекислого газа, выделяемого человеком при определенной умственной работе, проведены натурные экспериментальные исследования, результатом которых является подтверждение характера и динамики изменения углекислого газа в помещении при отсутствии (бездействии) вентиляционных систем (линейная зависимость), а также уточнение величины выделяющейся двуокиси углерода при конкретном виде умственной деятельности (исследовался труд инженера-проектировщика). Intellectual work is quite diverse and is characterized by different degrees of responsibility, monotony, attention, the level of emotional tension. In order to ensure comfortable conditions for a person staying at a permanent workplace among other things it is necessary to arrange climate control systems. The most promising ventilation systems for the above activities are personal ones that provide high-quality air environment in the breathing zone of a person while reducing capital and operating costs compared with traditional types of ventilation systems (mixing, displacement ventilation). However, the design of such systems should be guided not by the "average conditional person" but by the individual characteristics of the worker (age, gender, etc.) performing a particular type of mental activity. In order to clarify the actual value of carbon dioxide emitted by a person doing a particular mental work, we conducted a series of field experimental studies. They resulted in confirmation of the nature and dynamics of changes in carbon dioxide in the room in the absence (inactivity) of ventilation systems (linear dependence). As well we clarified the value of emitted carbon dioxide at a particular type of mental activity (in this article we studied the work of an engineer-designer).


Author(s):  
Parastoo Sadeghian ◽  
Christophe Duwig ◽  
Olof Sköldenberg ◽  
Ann Tammelin ◽  
Ardalan Rahimi Hosseini ◽  
...  

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