Ventilation Equipment Research Articles

Influence of trains meeting on the ventilation performance of equipment compartment with independent air duct in high-speed train: numerical and experimental study

AbstractDuring the train meeting events, train equipment compartments are exposed to the worst pressure changes, potentially affecting the ventilation performance of equipment, particularly for electrical facilities equipped with independent air ducts. In this paper, a two-step method is used for numerical computation: (1) obtaining the temporal and spatial transient node data of the flow field sections during the train-passing simulation and (2) using the data as the input data for the equipment compartment simulation. In addition, this paper also compares the difference in equipment ventilation between the single-train and train-passing scenarios in real vehicle tests. The results indicate that the primary factors influencing ventilation effectiveness are the aerodynamic compression and deceleration of airflow induced by the other train’s nose, as well as the instability of the external flow field in the wake of the other train. During train crossing, the air is forced into the air duct, with a maximum ratio of the airflow in-duct to the airflow out-duct reaching 3.2. The average mass flow falls below the rated mass flow for the converter. Compared to the rated air volume of converter, the maximum suppression rates obtained from testing and simulation are – 24.5% and – 16.8%, respectively. Compared to the single-train operation, the maximum suppression rates obtained from testing and simulation are – 15% and – 18%, respectively. These findings provide valuable insights into the design and operation of high-speed trains.

Device-free crowd counting using multi-link WiFi CSI for occupant-driven energy management of HVAC systems

ABSTRACT Accurate estimation of the number of occupants in a building’s thermal zone is a crucial input for the dynamic estimation of the cooling load of a heating, ventilation, and air conditioning equipment. This data, in conjunction with an intelligent control algorithm, can be judiciously employed for enhancing occupant comfort and achieving substantial energy savings through demand-driven operation. In this work, we propose a WiFi channel state information (CSI) based passive people counting model that utilizes a wavelet-based signal denoising scheme and an artificial neural network (ANN) model for automatic feature extraction. The application of the proposed model on a public dataset shows more than 99% accuracy in detecting up to eight people in three rooms of varying sizes. The proposed model was also validated on CSI samples collected from a laboratory environment with five occupants, using ESP32, a low cost and low power IoT device. The results show that the proposed model can perform people counting with an accuracy of up to 98%, using single- and multi-link measurements.

Post-Occupancy Evaluation of Adaptively Reused Historical Ecological Buildings in Egypt: The Case of Wekalet Al-Ghoury

Ecological historical buildings were originally designed to maintain acceptable Indoor Environmental Quality (IEQ) for their users and their intended activity. The adaptive reuse of these buildings is considered a great potential opportunity. As a result, these structures and their passive applied strategies might be no longer as effective as they once were. The purpose of this study is to evaluate the user satisfaction with IEQ in an adaptively reused historical ecological building; Wekalet Al-Ghoury. This post-occupancy evaluation was conducted using a mixed method approach that involved the use of a questionnaire and a semi-structured interview. Quantitative results of the questionnaire were statistically evaluated using SPSS software and interviews were thematically analyzed. The questionnaire was first use to capture responses’ diversity among staff and tenants, the semi-structured interview has then helped to discuss and justify quantitative findings. Occupants were generally satisfied with thermal and acoustic conditions and dissatisfied the most with the low level of IEQ control, poor indoor air quality and inconsistent light distribution. On the other hand, the interview has reflected responsive occupant behaviour to perform their work where occupants are free to change their place, change their working hours and introduce some movable lighting and ventilation equipment.

Способ улучшения зоогигиенических условий выращивания цыплят-бройлеров

Abstract. The purpose of the study is to study the effect of bedding material on the physiological parameters of broiler chickens. Since the most important condition for optimizing the microclimate in the poultry house is compliance with the physiological state of the livestock and maintaining its vital activity at an optimal level. Research methods. The experiment was carried out in the industrial conditions of a poultry farm on broiler stock of the Arbor Acres+ cross in the experimental workshop, where four sections were formed. The growth and development of broilers was monitored daily, livestock records were carried out, and a weekly veterinary report was compiled on the causes of mortality. Also, laboratory studies were carried out according to approved methods for the following indicators: ammonia content, sanitary and hygienic indicators of bedding material, volume, weight and moisture content of bedding material, as well as productivity and basic blood parameters of broiler chickens. Results. Trends in the positive effect of the sorbent in the form of modified diatomite on the productivity of broiler chickens due to the improvement of zoohygienic growing conditions have been identified. In particular, the content of the total number of microorganisms, mold spores and ammonia content in the production experimental workshop is examined in detail. During the work, the volume and weight of bedding material was calculated, including at the exit from the poultry house. We tried to pay special attention to blood biochemistry, which made it possible to assess the physiological state of broiler chickens and draw conclusions about the quality of feeding rations. At the same time, problematic issues associated with feeding poultry were identified, which affect the content of mineral elements in the blood. When determining the performance criterion, calculations were carried out using the EPEF index. Scientific novelty. For the first time, it was proven that the use of diatomite with a bulk layer height of 0.5–1 cm with a granule size of at least 5 mm as bedding material leads to improved zoohygienic conditions for raising broiler chickens without additional capital investments in the form of installation of expensive ventilation equipment or the use of additional technological operations. This replacement option has a positive effect on the health of young poultry.

Anaesthetic practices and attitudes to patient safety in a sample of Australian veterinary practices

ObjectiveTo survey anaesthetic practices and attitudes towards veterinary patient safety in Australia. Study designThis was a cross-sectional sample population from Australian veterinary practices, including first opinion small animal, mixed animal and referral small animal practices. The survey included practices’ anaesthetic management, monitoring equipment and topics regarding patient safety. ResultsResponses were obtained from 310/1700 (18%) veterinary practices, with 208 respondents from small animal practices (67%), 71 mixed animal practices (23%) and 31 referral small animal centres (10%). Overall, 61% of respondents reported always having a dedicated staff member monitoring the anaesthetic, who was most commonly a certified veterinary nurse (89%). In 22% of the practices, some of the staff monitoring an anaesthetic did not have any qualification. Completion of anaesthetic plans for each animal prior to an anaesthetic was reported by 24.5% of respondents and labelling of syringes was completed in 80% of practices. Pulse oximetry (98%) and temperature (88%) were the most common clinical variables monitored. The use of capnography (46%) or an electrocardiogram (48%) was also reported by the respondents. Emergency drugs, airway and ventilation equipment are available in 96%, 88% and 59% of practices, respectively. A defibrillator was available in 11% of practices with only 54% respondents being confident in using it. Of the respondents 60% were aware of anaesthesia safety interventions and clinical guidelines regarding patient safety during anaesthesia. Conclusions and clinical relevanceDespite practices showing a relative improvement over the years in the standard of anaesthesia care, most of them are still not meeting international guidelines. Areas where changes could lead to improved safety practices could include: a trained person dedicated to monitor anaesthesia, pain scoring evaluation in patients recovering from anaesthesia, an increased use of standardised handover checklists, record keeping and an increase in open discussion of adverse events by the veterinary team.

Comparing the life cycle costs of a traditional and a smart HVAC control system for Australian office buildings

Many smart technologies have been introduced in buildings with the aim to reduce the energy and GHG emissions associated with their operation, particularly through improved control systems for regulating heating, ventilation and air conditioning (HVAC) equipment. Despite their energy saving potential, only a few studies have comprehensively assessed the costs associated with their practical implementation from a life cycle perspective. Accordingly, this study quantifies and compares the life cycle costs of a smart HVAC control system with that of a traditional control system, in the context of an Australian office building. For both systems, the required hardware are specified based on the characteristics of these systems and the layout of the serviced spaces in the reference building. The costs incurred over the period of assessment are quantified using the net present cost (NPC) approach. To evaluate the effects of these control systems on the operational energy costs of the building HVAC system, the control logics of both these systems are modelled through building energy simulations. The results show that, over the period of assessment, the smart control system incurred a higher total cost compared to the traditional control system. However, the findings from the simulations show that the HVAC energy cost savings achieved through the specification of the smart control system offset the additional cost incurred to deploy this system over the traditional control system. The smart control system resulted in HVAC operational cost savings between 9 % and 10 % compared to the traditional control system. Sensitivity analyses indicated that the total life cycle costs varied between −27 % and +50 %, with the discount rate and energy price increase rate being the most influential parameters.

Multimodal Framework for Smart Building Occupancy Detection

Over the years, building appliances have become the major energy consumers to improve indoor air quality and occupants’ lifestyles. The primary energy usage in building sectors, particularly lighting, Heating, Ventilation, and Air conditioning (HVAC) equipment, is expected to double in the upcoming years due to inappropriate control operation activities. Recently, several researchers have provided an automated solution to turn HVAC and lighting on when the space is being occupied and off when the space becomes vacant. Previous studies indicate a lack of publicly accessible datasets for environmental sensing and suggest developing holistic models that detect buildings’ occupancy. Additionally, the reliability of their solutions tends to decrease as the occupancy grows in a building. Therefore, this study proposed a machine learning-based framework for smart building occupancy detection that considered the lighting parameter in addition to the HVAC parameter used in the existing studies. We employed a parametric classifier to ensure a strong correlation between the predicting parameters and the occupancy prediction model. This study uses a machine learning model that combines direct and environmental sensing techniques to obtain high-quality training data. The analysis of the experimental results shows high accuracy, precision, recall, and F1-score of the applied RF model (0.86, 0.99, 1.0, and 0.88 respectively) for occupancy prediction and substantial energy saving.

Material Flow Analysis and Occupational Exposure Assessment in Additive Manufacturing End-of-Life Material Management.

Additive manufacturing (AM) offers a variety of material manufacturing techniques for a wide range of applications across many industries. Most efforts at process optimization and exposure assessment for AM are centered around the manufacturing process. However, identifying the material allocation and potentially harmful exposures in end-of-life (EoL) management is equally crucial to mitigating environmental releases and occupational health impacts within the AM supply chain. This research tracks the allocation and potential releases of AM EoL materials within the US through a material flow analysis. Of the generated AM EoL materials, 58% are incinerated, 33% are landfilled, and 9% are recycled by weight. The generated data set was then used to examine the theoretical occupational hazards during AM EoL material management practices through generic exposure scenario assessment, highlighting the importance of ventilation and personal protective equipment at all stages of AM material management. This research identifies pollution sources, offering policymakers and stakeholders insights to shape pollution prevention and worker safety strategies within the US AM EoL management pathways.

Twelve tips for developing and implementing an effective critical care simulation programme

Simulation training in healthcare settings has become a valuable training tool. It provides an ideal formative assessment for interdisciplinary teaching. It provides a high fidelity and highly immersive environment where healthcare staff and students can practice developing their skills in a safe and controlled manner. Simulation training allows staff to practice skills that better prepare them for clinical emergencies, therefore possibly optimising clinical care. While the benefits of simulation education are well understood, establishing a programme for use by critical care staff is complex. Complexities include the highly specialised scenarios that are not typically encountered in non-critical care areas, as well as the need for advanced monitoring equipment, ventilation equipment etc. These 12 tips are intended to assist healthcare educators in navigating the complexities in the establishment of a critical care simulation programme, providing advice on selecting target audiences, learning outcomes, creating a critical care simulation environment and recommendations on evaluation and development of the programme.

APPLICATION OF AUTOCAD SYSTEM FOR COMPUTER DESIGN IN ENVIRONMENTAL PROTECTION TECHNOLOGIES

Environmental protection technologies touch different issues, including modern technologies and the latest materials in the decoration of interiors and exteriors, modern equipment for ventilation, interior heating, modern lighting systems and energy-saving technologies, modern methods of project activities of an interior or exterior designer. AutoCad automated design system is a technology that allows you to ensure predictability, speed and quality of work with projects when creating and applying environmental protection and interior and exterior elements. The ability to develop accurate models and perform visualization in 3D improves the perception of what is being designed or developed.

Numerical Study of the Strength Radial Turbomachines Based on the Use of Stainless Steel 316L

By studying various properties of materials came to the conclusion that stainless steel 316L has good properties. This material is suitable for making radial wheel turbines compared to other materials. The object of the study is a radial wheel with 10 blades manufactured by “Schiele” (Germany), which specializes in the production of units for the chemical industry and ventilation equipment. The finite element method was chosen as the basic research method for solving problems of natural and forced vibrations, static stress and studying the degree of reactivity blades radial wheels of turbomachines. It can be argued that the numerical analysis of the strength characteristics of heavily loaded turbine elements with the help of electronic computers provides a greater depth of research, the breadth of the issues covered, significantly reduces the amount of expensive experimental research, reduces the time for designing new turbines in terms of efficiency, reliability, technology and resource saving of highly loaded units. In this paper, calculations were made of the characteristics of natural frequencies, equivalent stresses, deformation and the degree of reactivity blades when using material stainless steel 316L. It is noted that this material provides the criterion of stress concentration in the wheel as low as possible and the natural frequencies of the wheel are reduced, but it does not lead to a change in the oscillation modes of this wheel. So 316L stainless steel is recommended for evaluating options in the manufacture of this radial wheel of turbomachines in the field of power, chemical and transport engineering.

Problem of increased humidity in ice arenas and possible solutions

This paper reviews the problem of high humidity in an ice arena in Sochi and ways of solving it. The authors consider the ventilation system structure and determine the causes of the high humidity—moisture in the water vapor forms and a cold surface of ice cools the surrounding space and objects. The consequences of this air state are fogging over the ice surface, namely, condensate formation, which exacerbates the quality of the ice rink, corrosion of steel and iron structures, and mold attack. In addition, the facility microclimate is uncomfortable for people to stay there. During this study, the authors identified several ways to achieve the necessary indoor air parameters. The first method is sorption dehumidification. This system can function at low temperatures and cope with extreme dampness, but it has significant costs. The second method, which is simpler and more effective, is assimilation. This method is based on the ability of warm air masses to hold a larger amount of water vapor than cold air masses. This method for improving the air parameters is more effective when required to modify an existing ventilation system. In this particular case, in the ice arena in Sochi, assimilation was the most effective method. Air coolers with a drift eliminator were installed in the existing ventilation system. The calculation of the selected heat exchangers was performed using ventilation equipment selection software (VESS).

Study on causative model of acute occupational poisoning accidents based on interpretative structural model-Bayesian network

Objective: To further study the causes of acute occupational poisoning accidents, and to provide scientific basis and decision support for the prevention of accidents in advance. Methods: From September 2022 to May 2023, the literature was searched and 232 cases of acute occupational poisoning cases occurred from 2013 to 2022 were collected. The causal nodes of the accident were determined according to the expert score, and the interpretative structural model (ISM) was used to construct the correlation model between the causal nodes to obtain the hierarchical relationship between the factors. The influence of each causal node on the occurrence of acute occupational poisoning accidents was studied by using Bayesian network (BN), and the relationship and influence among the causal nodes were analyzed by Netica 5.18 software to establish the pre-prevention model of acute occupational poisoning accidents and identify the key causal factors. Results: A total of 23, 203, and 6 cases of significant, large, and medium acute occupational poisoning accidents were included, of which 179, 29, and 24 cases were asphyxiating gas, irritating gas, and mixed gas, respectively. ISM of acute occupational poisoning accidents divided the causal factors into a 7-layer and 3-level hierarchical structure model. Among them, operation conditions, protective measures, ventilation equipment, hidden trouble investigation, emergency management, illegal operation, equipment and facilities, and blind rescue were the direct causes of the occurrence and expansion of accidents. Warning devices, inspection situation, safety education situation, safety operation procedures, and technology in the production process were indirect influences that lead to the occurrence and expansion of accidents. Safety production responsibility system, enterprise supervision and management and government supervision were the deep-rooted influences. BN reasoning showed that the maximum probability causal chain of acute occupational poisoning accidents was as follows: safety production responsibility system→enterprise supervision and management→safety education and training→protective measures→accident occurrence. The key factors leading to the occurrence of acute occupational poisoning accidents were inadequate protective measures, equipment and facility failures, operational errors, ventilation equipment not being used properly and improper emergency management. Conclusion: In the prevention of acute occupational poisoning accidents, it is necessary to correctly use protective measures, test equipment and facilities before operation, operate according to regulations, ensure the normal use of ventilation equipment, and strengthen emergency management, so as to reduce the incidence of acute occupational poisoning accidents.

Background noise and reverberation time in a college classroom

A sound survey of noise levels in unoccupied classrooms on the Marietta Campus of Kennesaw State University identified one classroom as the most problematic in terms of background noise levels. This level is mostly associated with heating, ventilation, and air-conditioning equipment. Excessive background noise in learning spaces diminishes the speech intelligibility from the speaker to the listeners and can cause stress and fatigue. The overall A-weighted average sound levels are compared with ANSI-ASA S12.60-2010/Part 1 (Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools). In addition, frequency analysis of the background sound and time variations are studies. Binaural headset microphone measurements are compared to the single microphone measurements. Reverberation time is measured using the engineering survey method and compared to the ANSI guidelines.

Survey of background noise levels inside classrooms on a college campus

Sound level measurements were made for 18 classrooms and learning spaces on the Marietta Campus of Kennesaw State University, Georgia, USA. Excessive background noise in learning spaces diminishes the speech intelligibility from the speaker to the listeners. The noise measured was in empty or nearly empty classrooms with no one talking. The primary background noise source was observed to be due to heating, ventilation, and air-conditioning equipment. The results are compared with a student survey to see if the noise complaints correlate with the noisiest classrooms in terms of their average A-weighted decibel levels. In addition, conformance with ANSI-ASA S12.60-2010/Part 1 (Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools) is evaluated.

Research on mine ventilation network solution and collaborative control technology

With the development of intelligent ventilation system in domestic coal mines, the demand for ventilation network solving software is becoming more and more intense. Aiming at the problem that the traditional ventilation network solution algorithm is difficult to meet the increasingly complex ventilation system solution needs of domestic mines, and the lack of functions of the collaborative control of ventilation equipment and facilities, this paper uses theoretical analysis combined with mine reality to study the relevant theories and algorithms in the field of ventilation network solution and collaborative control at home and abroad, and optimizes the network solution and collaborative control related algorithms such as iterative calculation of ventilation network, identification and stability analysis of angle-linked wind network, natural wind pressure calculation, local fan collaborative control, and collaborative control of damper and wind window. Provide theoretical guidance for future network solution software development.

Performance evaluation of a mechanical ventilation simulation model for diverse respiratory complications

Medical life-saving techniques include mechanical ventilation. During the COVID-19 epidemic, the lack of inexpensive, precise, and accessible mechanical ventilation equipment was the biggest challenge. The global need exploded, especially in developing nations. Global researchers and engineers are developing inexpensive, portable medical ventilators. A simpler mechanical ventilator system with a realistic lungs model is simulated in this work. A systematic ventilation study is done using the dynamic simulation of the model. Simulation findings of various medical disorders are compared to standard data. The maximum lung pressure (Pmax) was 15.78 cmH2O for healthy lungs, 17.72 for cardiogenic pulmonary edema, 16.05 for pneumonia, 19.74 for acute respiratory distress syndrome (ARDS), 17.1 for AECOPD, 19.64 for asthma, and 15.09 for acute intracranial illnesses and head traumas. All were below 30 cmH2O, the average maximum pressure. The computed maximum tidal volume (TDVmax) is 0.5849 l, substantially lower than that of the healthy lungs (0.700 l). The pneumonia measurement was 0.4256 l, substantially lower than the typical 0.798 l. TDVmax was 0.3333 l for ARDS, lower than the usual 0.497 l. The computed TDVmax for AECOPD was 0.6084 l, lower than the normal 0.700 l. Asthma had a TDVmax of 0.4729 l, lower than the typical 0.798 l. In individuals with acute cerebral diseases and head traumas, TDVmax is 0.3511 l, lower than the typical 0.700 l. The results show the viability of the model as it performs accurately to the presented medical condition parameters. Further clinical trials are needed to assess the safety and reliability of the simulation model.

Are anesthesiologists and intensivists ready to fully working with domestically produced ventilators?

The objective was to determine the attitude of anesthesiologists and intensivists to the possibility of a complete transition to the use of domestic equipment for mechanical ventilation instead of imported ones.Materials and methods. An anonymous survey of members of the Association of anesthesiologists-intensivists, doctors with experience working on ventilators (code 232870 and 232890), using the Google Forms software service. The survey involved 227 specialists from different regions of the country working in hospitals with both more and less than 1000 beds.Results. At the workplaces of respondents, imported equipment predominates (91.6 %). The majority of experts (92.6 %) believe that the capabilities of domestic equipment relative to imported ones are lower, 0.4 % – higher, 7 % do not see any differences. The main complaints about modern domestic equipment: less reliability (84.1 %), fewer capabilities (71.4 %), worse interface work (60.4 %), worse service (25.6 %). 92.1 % do not consider it advisable to refuse to import devices, although 63.9 % of respondents do not work with domestically produced ventilators at all.Conclusion. Domestic anesthesiologists and intensivists are not ready to use exclusively domestically produced devices in their practical work. It is necessary to improve the interaction of the professional community with manufacturers of domestic respiratory equipment in order to disseminate the positive information about it.

Ventilation regulations and occupant practices: undetectable pollution and invisible extraction

This sociotechnical investigation examines the use of ventilation systems in homes in London, UK. These homes were built with ventilation systems as described by guidance in the UK Building Regulations Approved Document F. These systems are assumed to provide adequate ventilation rates. However, previous measurements in these homes show that ventilation rates are inadequate. Using social practice theory as a framework to analyse the qualitative data, the intended use of the ventilation systems is compared to participants’ actual practices of manipulating the indoor air, revealing discrepancies between the two. Occupants had limited knowledge of indoor pollutants but were highly motivated to control and interact with the smells and air in their homes. They primarily used technologies that were not part of the planned system, because the latter’s functioning was opaque to occupants and not well connected to their other practices. The highlighted discrepancies in four case study homes between planned and actual ventilation system operation help to identify how future systems could be improved to ensure adequate ventilation rates and good indoor air quality in airtight homes. Policy relevance This research investigates the extent to which the intended operation of domestic ventilation systems set out in Approved Document F to the UK Building Regulations is accomplished in practice. The findings show that ventilation equipment is not used as intended. The research suggests a need for future guidance to more actively consider routes by which occupants can learn how to use and maintain their ventilation systems, and how to identify and remove indoor air pollution. There is a risk of continuing underventilation in homes unless efforts are made to ensure the systems are easily interpretable and robust to a reasonable range of internal conditions and social contexts.

Effects of different dressings in the prevention of facial skin pressure injury related to non‐invasive ventilation: Systematic review and network meta‐analysis

AbstractTo investigate the preventive effect of different dressings on pressure injuries related to non‐invasive ventilation equipment and to screen the efficacy of dressings. Systematic review and network meta‐analysis. PubMed, the Cochrane Library, Web of Science, EMBASE, Cumulative Index to Nursing & Allied Health Literature (CINAHL), China Knowledge Resource Integrated Database (CNKI), Wanfang Database, Chinese Biomedical Database (CBM) and Weipu Database (VIP) were used for the search from the date of inception of each database to 15 October 2023. The quality of the data was assessed using the Cochrane Risk of Bias tool. Stata 16.0 Software was used to analysis and ranking of different types of dressings. A total of 23 randomized controlled trials on 7 interventions were included in the final analysis. The effectiveness of these in preventing the overall incidence of pressure injuries is ranked from best to worst as follows: hydrogel dressing > foam dressing > petroleum jelly gauze dressing > hydrocolloid dressing > film dressing > clean gauze dressing > sterile gauze. Sixteen studies reported the incidence of Stage I pressure injuries, the effectiveness in preventing the incidence of Stage I pressure injuries was ranked from best to least effective: foam dressing > hydrogel dressing > petroleum jelly gauze dressing > hydrocolloid dressing > film dressing > clean gauze dressing > sterile gauze dressing. Fourteen studies reported the incidence of Stages I/II pressure injuries, the effective in preventing the incidence of Stages I and II pressure injuries was ranked from best to least effective: foam dressing > hydrogel dressing > petroleum jelly gauze dressing > hydrocolloid dressing > clean gauze dressing > sterile gauze dressing. Considering the advantages and disadvantages of different dressings, both hydrogel and foam dressings are effective in preventing pressure injuries related to non‐invasive ventilation equipment.