Mechanical Ventilation System Research Articles

The effect of structural retrofitting and ventilation scenarios on the indoor microclimate of a historical library: The Necip Pasa Library, Turkiye

Structural retrofitting in buildings may result in changes in the indoor microclimate. Chemical, mechanical and biological deterioration can be seen in the cultural properties as a consequence of substrates and inappropriate microclimatic conditions such as high indoor temperature, relative humidity and fluctuations of them. The primary aim of the study is to evaluate the effect of the structural retrofitting, that the building underwent, on the chemical degradation risk of the library collection based on two different ventilation scenarios. One is natural ventilation which is an existing situation since the building is free-floating. The other one implementing a mechanical ventilation system into the building. To be able to compare the microclimate that affects the library collection pre- and post-retrofitting, two models are developed in DesginBuilder and simulated for both scenarios. According to the results of the post-retrofitting model, mechanical ventilation reduced the risk of chemical degradation by 38 %, while natural ventilation did not cause any effect. Natural ventilation gives a similar output in the pre-retrofitting model as in the post-retrofitting model. Mechanical ventilation in the pre-retrofitting model achieves a 33 % reduction in chemical degradation risk. Structural retrofitting only achieves a 1 % reduction in the chemical risk level for both ventilation scenarios. Thus, its effect on the indoor microclimate is insignificant. This study shows that creating simulation models effectively assesses potential risks pre-post-structural retrofitting or any retrofitting in historical buildings. Simulations reveal that mechanical ventilation is a better choice for decreasing chemical degradation risks for the library.

A New Tailored Approach to Calculate the Optimal Number of Outdoor Air Changes in School Building HVAC Systems in the Post-COVID-19 Era

Air conditioning systems can play a positive or negative role in the spread of COVID-19 infection. The importance of sufficient outdoor air changes in buildings was highlighted by the World Health Organization, therefore these should be guaranteed by mechanical ventilation systems or adequate air conditioning systems. The proposed case study concerns the optimal number of outdoor air changes to limit COVID-19 contagion for a school building in Central Italy. The Wells–Riley model is used to assess the risk of airborne infection, while energy consumption is calculated by a dynamic energy simulation software. The scope of the paper offers an innovative method to define the optimal ventilation strategy for the building’s HVAC system design to reduce the risk of infection with limited increases in energy consumption and greenhouse gas emissions. Results show that the desirable approach is the one in which the same low value of contagion risk is set in all rooms. This new approach results in significant energy savings, compared to the most common ones (setting the same high outdoor air rates for all rooms) to counteract the risk of infection. Finally, the zero-emission building target is verified by introducing a suitable photovoltaic system to offset pollutant emissions.

Airborne Influenza Virus in Daycare Centers.

In this study, we investigated the concentration of airborne influenza virus in daycare centers and influencing factors, such as common cold prevalence, air pollutants, and meteorological factors. A total of 209 air samples were collected from daycare centers in Kaohsiung and the influenza virus was analyzed using real-time quantitative polymerase chain reaction. Air pollutants and metrological factors were measured using real-time monitoring equipment. Winter had the highest positive rates of airborne influenza virus and the highest prevalence of the common cold, followed by summer and autumn. The concentration of CO was significantly positively correlated with airborne influenza virus. Daycare center A, with natural ventilation and air condition systems, had a higher concentration of airborne influenza A virus, airborne fungi, and airborne bacteria, as well as a higher prevalence of the common cold, than daycare center B, with a mechanical ventilation system and air purifiers, while the concentrations of CO2, CO, and UFPs in daycare center A were lower than those in daycare center B. We successfully detected airborne influenza virus in daycare centers, demonstrating that aerosol sampling for influenza can provide novel epidemiological insights and inform the management of influenza in daycare centers.

Integration of resilient cooling technologies in building stock: Impact on thermal comfort, final energy consumption, and GHG emissions

Buildings in the EU contribute significantly to energy consumption and greenhouse gas emissions, with HVAC systems being major contributors. This paper assesses the impact of the resilience of various cooling strategies on thermal comfort, energy consumption, and GHG emissions in the residential building stock in Belgium. This study uses an innovative approach for sizing and designing cooling systems, considering the impact of climate change on future weather conditions and extreme heatwaves. The findings reveal alarming temperature increases, with potential rises of up to 4.1 °C from the 2010s to the 2090s, particularly in the high-emission SSP5-8.5 scenario. The study investigates three cooling strategies: scenario 1 (mechanical ventilation), scenario 2 (mechanical ventilation and natural ventilation), and scenario 3 (mechanical ventilation, natural ventilation, and split system). In scenario 1, there is a notable increase in Indoor Overheating Degree (IOhD), reaching up to 586% in the 2090s for semi-detached buildings, while scenario 2 consistently reduces IOhD, reaching only 0.2 °C by the 2090s. Scenario 3 achieves near-zero IOhD by the 2050s and 2090s. Notably, the “Heatwave [2081–2100]" exhibits unprecedented daytime temperatures, peaking at 46.0 °C. During the 2054 heatwave, insulated buildings maintained the Indoor Operative Temperature (IOpT) below 40 °C, whereas non-insulated buildings reached 44.3 °C, indicating challenges in meeting thermal comfort standards. Furthermore, cooling energy consumption increased by 106%–141% in the 2050s and surge by 174%–280% in the 2090s compared to the 2010s, along with significant GHG emissions growth in the future scenarios, particularly in SSP5-8.5.

Integrating the Living Wall with Mechanical Ventilation to Improve Indoor Thermal Environment in the Transition Season

A living wall, when integrated with a mechanical ventilation system, can effectively improve the indoor thermal environment and reduce indoor CO2 concentration during the transition season. In this study, a control experiment was conducted to analyze the effect of a living wall integrated with mechanical ventilation (LW-V) on indoor air quality. During the experiment, indoor air temperature, relative humidity, indoor air speed, and CO2 concentration were measured, while the skin temperature was monitored and subjective questionnaires were administered to 60 subjects. The results show that the indoor environment was effectively improved by employing the LW-V system, with the average indoor temperature decreasing by 1.45 °C, while relative humidity increased by 19.1%. Due to the plant photosynthesis, CO2 concentrations were reduced by 13.83 ppm. Meanwhile, the mean skin temperature was reduced by 0.18 °C and was closer to the neutral mean skin temperature. Questionnaire analysis reveals the LW-V system improved overall air freshness sensation and thermal comfort level by 1.09 and 0.53, respectively. The LW-V system improved the indoor thermal environment as well as air quality during the transition season significantly.

Deep energy renovations’ impact on indoor air quality and thermal comfort of residential dwellings in Ireland – ARDEN project

As Europe's residential energy renovation programmes accelerate, field studies assessing their impact on indoor environmental quality are required to ensure maximum co-benefits to occupants' health and wellbeing. In this work, we evaluated the impact of deep energy renovation (DER) on indoor air quality (IAQ), ventilation, and thermal comfort in a sample of Irish homes (n = 12). Indoor air pollutants (IAPs), including particulate matter (PM2.5), carbon dioxide (CO2), carbon monoxide (CO), formaldehyde, radon, nitrogen dioxide (NO2), and BTEX, were measured pre and post DER. Performance of the newly installed mechanical ventilation systems was also assessed. Questionnaires and diaries were used to collect feedback regarding the retrofit and occupant activities. All occupants reported high levels of satisfaction with thermal comfort, and homes were significantly warmer post-retrofit (p < 0.0001). The DER improved indoor CO2 concentrations, indicating a positive impact on residential ventilation. However, many bedrooms were still under ventilated. PM2.5 (p < 0.0001) and formaldehyde (p < 0.05) concentrations increased post-retrofit. Higher concentrations of PM2.5 were most likely due to a combination of factors including inadequate ventilation, ingress from outdoors via open windows or doors, presence of a wood burning stove and other occupant activities. Retrofits were observed to have poor compliance with ventilation recommendations. Greater emphasis on pollutant source control along with proper installation and maintenance of mechanical ventilation systems is required to ensure DERs lead to sustainable and healthy homes.

A complete review on enhancing air circulation and filtration for improving internal air quality in a healthy school environment

The health of staff and students is impacted by Indoor Air Quality (IAQ) in educational environments. A healthy atmosphere depends on good IAQ, yet millions of students worldwide might develop respiratory illnesses due to poor air quality. Immediate action is required to alleviate the burden of IAQ consequences in the pandemic-dominated period. This detailed evaluation focuses on techniques for improving air circulation and filtration systems to meet the critical demand for improved IAQ in schools. This research demonstrates the negative impacts of inadequate IAQ on students and educators’ cognitive capacities, health and performance based on an extensive examination of current records. A healthy learning environment, on the other hand, can minimize absenteeism, raise test results and increase pupil/teacher education/teaching productivity. This review explores the effectiveness of different ventilation as well as filtration methods, such as air purifiers, mechanical ventilation, natural ventilation and advanced filtration systems, in lowering airborne pollutants like particulate matter, volatile organic compounds (VOCs) and microbiological contaminants. This study reviews current information, emphasizes recent findings along with options and provides guidelines for the future of education. It underlines the limits of previous studies, gives ideas for further research and indicates a path forward for more enhancements to the air quality in schools. Comprehensive analysis with greater sample numbers is required to evaluate student performance, indoor contentment and environmental health exposure. On-site measurements are essential for comprehending the properties of contaminants. Intricate mitigation strategies must take health impacts, IAQ and energy efficiency into effect.

Natural ventilation to improve indoor air quality (IAQ) in existing homes: The development of health-based and context-specific user guidelines

Acceptable indoor air quality (IAQ) is one of the most relevant aspects of a healthy home environment. Despite advances in mechanical and hybrid ventilation systems, natural ventilation still constitutes a crucial intervention to improve IAQ in existing homes; especially in older and/or vulnerable ones. The challenge, however, is optimizing natural ventilation strategies so IAQ is reached while thermal discomfort (and potentially associated energy consumption) is minimized.The complexity of identifying factors that may determine the possibilities of natural ventilation in existing homes has traditionally hindered the efforts from the scientific community to communicate straightforward answers for end-users. This work develops a methodology that, based on real case studies and through a series of simulations, provides simple, context-specific criteria and recommendations in order to reach acceptable IAQ through natural ventilation strategies in existing homes. The use of a minimum ventilation time (MVT) indicator, alongside considerations for different seasons and housing types, are translated into step-by-step guidelines aimed at helping the end-user to (i) gain knowledge regarding the opportunities and limitations for natural ventilation in the dwelling, and (ii) identify which specific actions should be carried out under different conditions to maintain minimum IAQ.The conceptual framework and methodology presented, while illustrated for the case of Barcelona, can be replicated for different cities or regions with differing housing characteristics and climatological conditions, and can easily accommodate other locally relevant factors.

Effects of internal wall design on cross-ventilation of an isolated building

Poorly designed internal walls deter natural ventilation of buildings, causing poor indoor air quality and exorbitant energy costs when mechanical ventilation systems are used. Although one can design internal walls with minimum adverse effects on natural ventilation by controlling height, width, location, and porosity of internal walls, less research has been done to date. This study investigated how these four parameters individually and collectively influence the cross-ventilation of buildings using Reynolds-average Navier–Stokes equation-based computational fluid dynamics simulations and the local and global sensitivity analysis. When considering individual parameters, the local sensitivity analysis revealed the positive correlation between internal walls' porosity and cross-ventilation, similar to previous studies. However, the global sensitivity analysis identified the location as the most influential design parameter for cross-ventilation. Furthermore, the global sensitivity analysis revealed nonlinear, non-monotonic, and interactive relations between cross ventilation and all parameters but porosity, highlighting the importance of evaluating all design parameters together and the difficulty in extrapolating the findings for idealized to actual internal wall designs. Based on the findings, this study proposes narrow internal walls with high porosities built away from ventilation openings as a basic internal wall design to maximize the cross-ventilation of buildings.

Energy efficiency in architecture: Strategies and technologies

Energy efficiency in architecture is a critical consideration in the design and construction of buildings, aiming to reduce energy consumption and minimize environmental impact. This abstract explores various strategies and technologies that can be implemented to enhance energy efficiency in architecture. The importance of energy efficiency in architecture lies in its potential to reduce greenhouse gas emissions, lower energy costs, and create healthier indoor environments. Achieving energy efficiency in architecture involves a combination of passive design strategies, such as orientation, shading, and natural ventilation, as well as active technologies, including high-performance insulation, energy-efficient lighting, and renewable energy systems. Passive design strategies are fundamental to energy-efficient architecture, utilizing the natural elements of sunlight, shade, and airflow to minimize the need for mechanical heating, cooling, and lighting. Proper building orientation, effective shading devices, and strategic placement of windows and openings can maximize natural light and ventilation, reducing the reliance on artificial lighting and mechanical ventilation systems. In addition to passive design strategies, active technologies play a crucial role in enhancing energy efficiency in architecture. High-performance insulation materials, such as aerogel and vacuum insulation panels, can significantly reduce heat loss and gain through building envelopes, improving thermal comfort and reducing energy consumption. Energy-efficient lighting systems, such as light-emitting diodes (LEDs) and daylight harvesting systems, can reduce electricity usage for lighting, while renewable energy systems, such as solar photovoltaic panels and wind turbines, can generate clean energy on-site, further reducing reliance on fossil fuels. Overall, energy efficiency in architecture requires a holistic approach that considers both passive design strategies and active technologies. By incorporating these strategies and technologies into building design and construction, architects and designers can create buildings that are not only environmentally sustainable but also comfortable, healthy, and cost-effective for occupants.

Analysis of air quality and ventilation systems in production working areas of PT. A

PT. A is a manufacturing industry specializing in plastic-based cosmetic packaging. The work area of blow molding and injection molding 1 &amp; 2 is the center of the company's main activity, involving many employees with diverse roles. The high density of work activity and heat-generating machines pose significant challenges to the workspace temperature, impacting worker health and well-being. Indoor air pollution levels, 2 to 10 times higher than outside, raise serious concerns, given people's prolonged indoor exposure. Poor air quality can lead to discomfort, health issues, and work accidents, affecting company operations and customer confidence. Three production units of PT. A were analyzed, focusing on air quality and ventilation systems. Primary data collection involved observations and interviews with four company informants regarding the ventilation system. Secondary data included direct measurements of air pollutants, dust particles, and environmental conditions by designated third parties. PT. A has implemented multiple mechanical ventilation systems to enhance airflow within the production area. Although the air quality in the blow molding and injection molding 1&amp;2 workspaces meets the standards of the Minister of Manpower of the Republic of Indonesia No. 5 of 2018, the working climate in these three production areas exceeds the specified thresholds. Engineering interventions are recommended to address this issue and improve worker safety, health, comfort, and productivity without long-term consequences.

Variability and health impact of air pollutants and bioaerosols in multi-functional indoor environments with mechanical ventilation system

The condition of indoor environments significantly impacts human daily life and health, where exposure to harmful substances affects the resilience of occupants. To understand the dynamics of indoor air quality and its implications for occupant health thus this study evaluated air pollutant concentration (TVOC, NO2, O3, CO, CO2, PM10, PM2.5, and PM1) and bioaerosol in mechanically ventilated offices, laboratories, corridors, a library and a mechanical workshop. Simultaneous measurements of all air pollutants were performed for 24 h, including non-working hours, while bioaerosol was sampled for fungal identification and quantified via the colony counting method. High concentrations of PM10, PM2.5, PM1, O3 and bioaerosol were found in the mechanical workshop, where these pollutants were strongly related to humidity (p < 0.05) and indoor source contributions. Other air pollutants such as TVOC had the highest concentrations in the office areas during working hours with an average concentration of 361 ± 14.8 μg m−3, while for CO, the highest concentration was observed in the laboratories for both working hours (442 ± 26.0 ppb) and 24 h average concentration (438 ± 22.1 ppb). Dominant species identified in bioaerosol were Aspergillus sp., Geotrichum sp., Fusarium sp., and Penicillium sp., where the exposure to bioaerosol was found to be of low risk to all workers as the hazard quotient (HQ) was <1 for all multi-functional indoor environments. The results from this study suggest that indoor air pollutants and bioaerosol concentrations have a variety of characteristics and source contributions, especially from human activities and indoor sources.

Assessment of Indoor Air Quality Performance in a Building at Kemaman, Terengganu

Violations of IAQ regulations can lead to sick building syndrome (SBS), which manifests as symptoms like respiratory difficulties, eye irritation, skin issues, and headaches. Monitoring IAQ is crucial for ensuring the well-being of occupants and preventing health issues and reduced productivity. Compliance with IAQ regulations is necessary to avoid legal concerns and penalties. The study aims to evaluates IAQ in accordance with the Department of Occupational Safety and Health (DOSH) Malaysia's Industry Code of Practice on Indoor Air Quality (ICOP 2010), which provides guidelines and acceptable limits for physical and chemical contaminants on the impact on occupants' health and comfort in Bangunan Persekutuan Kemaman, a government office building in Terengganu, Malaysia. Objective and subjective measurements were collected to assess physical parameters, chemical contaminants, and ventilation performance indicators. The data revealed that the airflow, relative humidity, and light intensity in the building did not meet the ICOP 2010 standards, indicating the need for repair and maintenance of the mechanical ventilation and air-conditioning (MVAC) system. The subjective survey completed by occupants indicated symptoms such as drowsiness, fatigue, and headaches, which are associated with poor IAQ. The study concludes that improvements are necessary to ensure compliance with IAQ regulations and recommends further research on the relationship between air temperature, relative humidity, and older building designs.

Indoor environmental quality in schools: NOTECH solution vs. standard solution.

In many Danish schools, the indoor environmental quality (IEQ) is challenged and studies document a poor IEQ in a majority of existing schools. Municipalities cannot afford comprehensive renovations and expensive mechanical ventilation solutions, hence public schools often suffer from poor indoor environment conditions. This study tests a new façade based, demand-controlled ventilation solution called NOTECH in the renovation of school. The study tests NOTECH vs. existing mechanical ventilation solution, comparing performance of both solutions at Skovbrynet Skole in Denmark. The project investigates the effect of the NOTECH solution in a primary school classroom, comparing it to a similar classroom with conventional, mechanical ventilation. Methodically, indoor environmental quality and energy performance is monitored in the two identical classrooms during one school year 2018 - 2019. The results show that both systems keep the conditions within acceptable limits and CO2 levels below 1000 ppm, which is the requirement according to the Danish Building Regulations. In terms of costs, the NOTECH system has a lower overall cost than the mechanical ventilation system, with total estimated costs for installation, heating, electricity and maintenance amounting to approximately 35% of the mechanical system's costs. Finally, the results show that the NOTECH solution has a smaller embedded CO2 footprint for building materials, reducing the estimated carbon load by 95% compared to the mechanical ventilation solution. While the performance of the both systems complies to the Danish Building Regulations, the indoor environmental quality between systems differs significantly. Results showing a higher air-temperature and lower relative air-humidity in the classroom with mechanical ventilation during winter and lower CO 2 levels in the mechanically ventilated classroom during winter and summer. Costs for implementation, energy consumption for heating and CO 2 footprint for building materials are significantly lower for the NOTECH solution, compared to the mechanical solution.

Window frame integrable air recuperation minichannel/minigap heat exchanger

This article describes an evaluation of mini heat exchangers operation as a decentralized mechanical ventilation system with recuperative heat recovery that can be integrated into the window frame. The relatively small yet efficient air recuperation system allows for retrofitting existing buildings by reducing the overall energy consumption and thus the CO2 emissions. The proposed design, unlike existing systems, is easy to scale up to various room sizes and is a promising solution for buildings where a centralized recuperation system cannot be implemented or interfering with the building’s facade is not allowed. Theexperimental research was carried out enabling to collect temperature, pressure drop, and volumetric flow rate measurements in a recuperation system with various minigeometries, namely minichannels withahydraulic diameter of 3.00 mm, minigaps with a hydraulic diameter of 5.82 mm, and minigaps withahydraulic diameter of 1.98 mm. The system was tested for a room air temperature of 22 °C and three values of outside air temperatures, namely 5 °C, 10 °C, and 15 °C. The volumetric flow rate for a single heat exchanger ranged from 4.1 m3/h to 20.4 m3/h. The results showed that higher temperature rise of supplied air andhigher energy efficiency of the heat recovery can be achieved for smaller airflows and higher differences between outside and room temperatures. For an exemplary 34 m2 office room, the 0.8-fold air exchange rate can be provided and 1 667.1kWh of annual energy savings can be achieved, corresponding to 50.3 % of total energy required for heating the air. Heat exchangers equipped with 3.00 mm minichannels recover a similar amount of heat as the ones equipped with 5.82 mm minigaps, even though the hydraulic diameter ofthe minichannel is almost 2 times smaller. Meanwhile, a 5.82 mm minigap reduces the pressure drop by 76 % compared to a 3.00 mm minichannel.

The Relationship between Mechanical Ventilation, Indoor Air Quality Classes, and Energy Classes in a Romanian Context

Nowadays, indoor air quality (IAQ) and the energy performance of buildings are two main scientific and technical challenges because they are in direct connection with human health and the depletion of energy resources. In this study, we analyzed the influence of an outdoor air flow introduced through a mechanical ventilation system, focusing on the two aforementioned topics. A standardized ventilation rate (25 m3/h/person) led to an increase in the indoor O3 concentration (from 5 μg/m3 to 50 μg/m3) and, simultaneously, to a decrease in the indoor CO2 concentration (from 2000 mg/m3 to 800 mg/m3), a decrease in the PM2.5 concentration (from 300 μg/m3 to 150 μg/m3), and the maintenance of a constant indoor HCHO concentration. In our study, a new, single indoor air quality index, IIAQ, is proposed. This new index presents different implications: on the one hand, it has the ability to simultaneously take into account several pollutant species, and on the other hand, it can prioritize the ventilation strategy that responds to the extreme values of a certain pollutant. Moreover, indoor air quality classes were elaborated, similar to energy classes. The possibility of using this new index simultaneously with energy consumption may lead to ventilation strategies that are adaptative to dynamic outdoor pollutant concentrations.

The impact of real-time carbon dioxide awareness on occupant behavior and ventilation rates in student dwellings

Although existing standards typically prescribe fixed ventilation rates, a large portion of the building stock lacks mechanical ventilation systems. Such buildings obtain outdoor air through unintentional infiltration, open windows, and the operation of exhaust fans, which are mainly dependent on user awareness and behavior. This study investigates whether the presence of a simple CO2 meter display can alter user behavior and improve indoor air quality (IAQ) in dwellings. We conducted a two-week monitoring of CO2 concentration, air temperature, and relative humidity in 60 student dwellings (bedrooms and living rooms) in Denmark and Switzerland. During the first week, the CO2 display was concealed, and occupants adhered to their usual routines. In the second week, occupants used the display's visual feedback to enhance IAQ when necessary. Results revealed that over 95% of dwellings witnessed a reduction in median CO2 levels during the second week, both overall and in individual rooms. Furthermore, a descriptive analysis of CO2 concentration step changes exceeding the thresholds of “normal variation” showed an increase in the number of negative step changes, indicating a shift in user behavior. These findings underscore the efficacy ofa display interface providing information on the indoor environment in triggering behavior changes and improving IAQ in dwellings.

The influence of displacement ventilation on indoor carbon dioxide exposure and ventilation efficiency in a living laboratory open-plan office

Good indoor air quality in office environments is essential for occupant health and productivity. In open-plan offices, displacement ventilation has been recognized for its higher efficiency compared to mixing ventilation. This study evaluates the performance of displacement ventilation in an open-plan office under cooling and heating conditions, considering various supply ventilation rates, supply air temperatures, and occupancy levels. Field measurements were conducted over three months in a living laboratory office in a high-performance building. The indoor environment was controlled by an independent variable air volume (VAV) air conditioning system. The supply ventilation rate ranged from 6 to 12 h−1. Real-time measurements of carbon dioxide (CO2) concentrations in the supply air, return air, and breathing zone of the office were conducted to assess occupants’ exposure to CO2 and ventilation efficiency. The results show that the supply ventilation rate plays an important role in shaping the air distribution and overall effectiveness of the mechanical ventilation system. Higher supply ventilation rates can enhance air distribution robustness, improving ventilation efficiency and reducing CO2 exposure under both cooling and heating conditions. These findings also suggest the need for an optimized control logic that differs from the conventional control logic used in VAV systems. Specifically, during the heating condition of displacement ventilation, it is recommended to maintain the supply ventilation rate at a higher level to effectively mitigate the impact of occupant behavior on air quality, minimize CO2 exposure risks, and ensure a more robust and reliable indoor air distribution.

Compartmentalization and ventilation system impacts on air and contaminant transport for multifamily buildings

Provision of acceptable indoor air quality in multifamily buildings (MFBs) depends on the interior air flows that impact dilution of contaminants, cross-contamination between units and building energy use. The airtightness of interior partitions and design of ventilation systems in MFBs determine the flows across building partitions. These flows change the total ventilation rate for the building and individual units, and impact the mixing of air and contaminants between apartment units or with common spaces. This study examines the changes in air flow and contaminant transport in MFBs using combined CONTAM/EnergyPlus models. Key parameters were systematically varied, including climate, apartment airtightness, and mechanical ventilation system type. Simulations were performed for mid-rise buildings with and without an enclosed common corridor, and a 20-story high-rise building. Contaminants simulated in the analysis were PM2.5, formaldehyde, water vapor, and CO2. Key results of this work are that current airtightness requirements in ASHRAE 62.2 sufficiently limit transport of key contaminants, independent of the type of ventilation system across all three building typologies, and significantly reduce energy use in colder climates. The results of this work are intended to assist codes and standards bodies in setting appropriate airtightness limits and ventilation system design guidelines for MFBs.

ГАЗОВОЕ ОБОРУДОВАНИЕ В БЫТУ – РИСК ОТРАВЛЕНИЯ УГАРНЫМ ГАЗОМ

Currently, the number of cases of carbon monoxide poisoning continues to remain high. The article provides examples of the occurrence of carbon monoxide and the reasons for its accumulation in the room. According to statistics, in Russia gas poisoning ranks second in the structure of causes of death from acute poisoning of chemical etiology. Over the 6 months of 2023, 19 cases of poisoning were registered, 6 of which (31.6 %) resulted in the death of the victims. In the structure of violent death (8078 cases), fatal poisoning ranks third after mechanical injuries and mechanical asphyxia and accounts for 6.3 % (513 cases). The article presented measurements and calculations from which conclusions were drawn about the immediate causes of the formation of carbon monoxide in the room. Data from technical examinations and world literature on CO poisoning were studied and analyzed. It was found that the most common reasons for the formation of carbon monoxide in the premises were insufficient air exchange in the premises, the use of mechanical ventilation systems in apartments where this was not provided, the inoperability of ventilation ducts, the shutdown of gas equipment safety systems and violations in the installation of gas equipment. This article also provides recommendations that will allow defending yourself and your loved ones from the danger of carbon monoxide poisoning. The problem of carbon monoxide is global; in order to prevent poisoning from combustion products, everyone needs to know the rules for using gas equipment and the basic principles of air exchange.