The amount of moisture in the air is represented by relative humidity(RH);an ideal level of humidity in the interior environment is between 40%and 60%at temperatures between 18°and 20°Celsius.When the RH fal...The amount of moisture in the air is represented by relative humidity(RH);an ideal level of humidity in the interior environment is between 40%and 60%at temperatures between 18°and 20°Celsius.When the RH falls below this level,the environment becomes dry,which can cause skin dryness,irritation,and discomfort at low temperatures.When the humidity level rises above 60%,a wet atmosphere develops,which encourages the growth of mold and mites.Asthma and allergy symptoms may occur as a result.Human health is harmed by excessive humidity or a lack thereof.Dehumidifiers can be used to provide an optimal level of humidity and a stable and pleasant atmosphere;certain models disinfect and purify the water,reducing the spread of bacteria.The design and implementation of a client-server indoor and outdoor air quality monitoring application are presented in this paper.The Netatmo station was used to acquire the data needed in the application.The client is an Android application that allows the user to monitor air quality over a period of their choosing.For a good monitoring process,the Netatmo modules were used to collect data from both environments(indoor:temperature(T),RH,carbon dioxide(CO_(2)),atmospheric pressure(Pa),noise and outdoor:T and RH).The data is stored in a database,using MySQL.The Android application allows the user to view the evolution of the measured parameters in the form of graphs.Also,the paper presents a prediction model of RH using Azure Machine Learning Studio(Azure ML Studio).The model is evaluated using metrics:Mean Absolute Error(MAE),Root Mean Squared Error(RMSE),Relative Absolute Error(RAE),Relative Squared Error(RSE)and Coefficient of Determination(CoD).展开更多
Besides the need for low-cost instruments for air pollution measurement and detection,nowadays there are many concerns about air pollution due to the fast changes and used technologies.This research was applied using ...Besides the need for low-cost instruments for air pollution measurement and detection,nowadays there are many concerns about air pollution due to the fast changes and used technologies.This research was applied using an MQ2 gas detector,and microcontroller/Arduino-Uno.The design steps included bonding and connecting readymade sensors,coding,and finally testing the device.Testing has been conducted in Environment and Pollution Engineering Department laboratories,at the Technical Engineering College of Kirkuk.This study proposed the use of an MQ2 sensor for multi-gas rate detection which can exist indoors.The system uses also a DHT22 sensor for measuring environment temperature and humidity.The sensors are connected to Arduino and LCD to present data on LCD by powering the system with external power.Overall,the testing was conducted,and the device served as a measuring tool for indoor air as an accurate multi-gas rate detector.展开更多
To study the indoor air qualities（IAQ）of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,...To study the indoor air qualities（IAQ）of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,is investigated.A questionnaire survey and field tests are used to collect data.According to the data of twelve rooms in this building,objective evaluation and the subjective evaluation of the IAQ are obtained.Almost all of the environmental parameters in these rooms basically meet the standards of the objective evaluation.But the average concentration of carbon dioxide in most rooms cannot reach the value of the cleanliness standards,1 255 mg/m^3.The average acceptability of the IAQ in these rooms is 71%,which is lower than the value of the ASHRAE 55—1992 standards,80%.The proper increase in the wind speed and the indoor fresh air supply can greatly improve the objective evaluation and the subjective evaluation of the IAQ.展开更多
2022 Indoor Air Quality(IAQ),particularly in educational facilities,is gaining considerable interest and is a synonymous indicator towards evaluating human comfort.Factors such as CO_(2) concentration,temperature,and ...2022 Indoor Air Quality(IAQ),particularly in educational facilities,is gaining considerable interest and is a synonymous indicator towards evaluating human comfort.Factors such as CO_(2) concentration,temperature,and humidity play crucial parts in determining an acceptable level of IAQ.Many studies have also demonstrated that the indoor air quality of classrooms affects students’concentration and performance.Today with the threat of a global pandemic,the demand of clean&fresh indoor air quality in education buildings is extremely intensive.This study focuses on investigating IAQ situations and changes in different typical functional spaces of a higher education building in the UK.CO_(2),temperature,and humidity data in various learning environment were monitored via data loggers during the winter.Associated with data monitoring,a set of questionnaires surveys were carried out to evaluate the user’s experience.The results of this study show that temperature and CO_(2) concentration in the classrooms was constantly higher than the government guidance on a daily basis.The analysis also shows that temperature and humidity increased with CO_(2) levels,but at a much lower rate.This study has revealed poor and concerning IAQ in higher education buildings in the UK,particularly in larger rooms with high occupancy.Along with the findings,this paper also identifies possible impact or factors and proposes solutions to overcome these issues.展开更多
To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the dis...To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the distribution of the indicators of indoor air in the gymnasium to check the air-conditioning parameters reasonable or not. And there was a questionnaire for audiences and staff about the acceptance and satisfaction of the thermal comfort,simultaneously,some environmental parameters were monitored. Then an experiment was carried out in gymnasium with the plate sedimentation to the biological aerosol in the air. Finally,the thermal comfort and IAQ in the gymnasium were assessed based on the results of above questionnaire survey and measurements. The results show that most parameters of the environmental are within the standard limits of thermal comfort and IAQ in the monitored period,and the biological contaminants initially come from human beings. The main species in the gymnasium are streptobacillus,coccus,cladosporium,penicillium and neurospora.展开更多
Environmental monitoring of airborne formaldehyde (FA) using sensitive methodologies is fundamental to prevent health risks. The objective of this study was to compare three different FA monitoring methods during the ...Environmental monitoring of airborne formaldehyde (FA) using sensitive methodologies is fundamental to prevent health risks. The objective of this study was to compare three different FA monitoring methods during the daily activities of an anatomic pathology laboratory. Daily eight-hour measurements deriving from Radiello® passive diffusive samplers (PDS), NEMo XT continuous optical sensor (COS), and multi-gas 1512 photoacoustic monitor (MPM) were simultaneously compared over a period of 14 working days. Given the different daily distributions of the measurements performed by the three devices, all measurements were time-aligned for comparison purposes. The 95% limit of agreement (LOA) method was applied to estimate the degree of concordance of each device with respect to the others. Formaldehyde arithmetic mean measured using PDS was 32.6 ± 10.4 ppb (range: 19.8 - 62.7). The simultaneous measures performed by COS and MPM were respectively 42.4 ± 44.8 ppb (range: 7.0 - 175.0) and 189.0 ± 163.7 ppb (range: 40.0 - 2895.4). The MPM geometric mean (171.3 ppb) was approximately five times higher than those derived from COS (32.3 ppb) and PDS (31.4 ppb). The results of the LOA method applied to log-transformed FA data showed the same systematic discrepancies between MPM and the other two devices. A good agreement between PDS and COS could lead to a tailored approach according to the individual specificity of these techniques. This tool may be useful for accurately assessing the risk of FA exposure among healthcare workers. However, the limited specificity of the MPM does not support its use as a monitoring method for FA in the workplace.展开更多
Increasing incidents of indoor air quality(IAQ) related complaints lead us to the fact that IAQ has become a significant occupational health and environmental issue. However, how to effectively evaluate IAQ under diff...Increasing incidents of indoor air quality(IAQ) related complaints lead us to the fact that IAQ has become a significant occupational health and environmental issue. However, how to effectively evaluate IAQ under different scale of multiple indicators is still a challenge. The traditional single-indicator method is subjected to uncertainties in assessing IAQ due to different subjectivity on good or bad quality and scalar differences of data set. In this study, a multilevel integrated weighted average IAQ method including initial walking through assessment(IWA) and two-layers weighted average method are developed and applied to evaluate IAQ of the laboratory building at the University of Regina in Canada. Some important chemical parameters related to IAQ in terms of volatile organic compounds(VOCs), methanol(HCHO), carbon dioxide(CO2), and carbon monoxide(CO) are evaluated based on 5 months continuous monitoring data. The new integrated assessment result can not only indicates the risk of an individual parameter, but also able to quantify the overall IAQ risk on the sampling site. Finally, some recommendations based on the result are proposed to address sustainable IAQ practices in the sampling area.展开更多
Providing comfortable indoor air quality control in residential construction is an exceedingly important issue.This is due to the structure of the fast response controller of air quality.The presented work shows the b...Providing comfortable indoor air quality control in residential construction is an exceedingly important issue.This is due to the structure of the fast response controller of air quality.The presented work shows the breakdown and creation of a mathematical model for an interactive,nonlinear system for the required comfortable air quality.Furthermore,the paper refers to designing traditional proportional integral derivative regulators and proportional,integral,derivative regulators with independent parameters based on a backpropagation neural network.In the end,we perform the experimental outputs of a suggested backpropagation neural network-based proportional,integral,derivative controller and analyze model results by applying the proposed system.The obtained results demonstrated that the proposed controller can provide the required level of clean air in the room.The proposed developed model takes into consideration international Heating,Refrigerating,and air conditioning standards as ASHRAE AND ISO.Based on the findings,we concluded that it is possible to implement a proposed system in homes and offer equivalent indoor air quality with continuous mechanical ventilation without a profuse amount of energy.展开更多
Indoor air environment includes indoor thermal environment and air quality, and a reasonable ventilation provides guarantee for a good indoor environment. A numerical study of the indoor environment in different venti...Indoor air environment includes indoor thermal environment and air quality, and a reasonable ventilation provides guarantee for a good indoor environment. A numerical study of the indoor environment in different ventilation is presented in this paper. The External Energy Saving Lab of the WenYuan Building was selected for this purpose, and its indoor air quality and thermal performance in the typical summer climate were simulated. For the numerical simulation, the techniques of Fluent Air-pak was adopted to establish the physical and numerical model of lab. A attention is given to the velocity field and the distribution of pollutant concentration, followed by a discussion of two ventilation modes (displacement ventilation and up-in and up-out ventilation). By comparison, it is found that the Displacement ventilation in improving indoor air quality is obviously superior to the traditional up-in and up-out ventilation.展开更多
In this study, the indoor environmental quality (IEQ) in air conditioned residential buildings in a dry desert climate is examined from the perspective of occupants via two aspects: thermal comfort and indoor air qual...In this study, the indoor environmental quality (IEQ) in air conditioned residential buildings in a dry desert climate is examined from the perspective of occupants via two aspects: thermal comfort and indoor air quality. The study presents statistical data about the domestic-occupant thermal comfort sensations together with data describing the indoor air quality in Kuwaiti residential buildings. With respect to the latter, the overall IEQ acceptance using two measurements namely: physical measurements and subjective information collected via questionnaires, was used to evaluate 111 occupants living in twenty five air-conditioned residential buildings in the state of Kuwait. The operative temperature based on Actual Mean Vote (AMV) and Predicted Mean Vote (PMV) was identified using linear regression analysis of responses on the ASHRAE seven-point thermal sensation scale and was found to be 25.2°C and 23.3°C, respectively, in the summer season. Indoor air quality (IAQ) with respect to carbon dioxide concentration level was compared with the acceptable limits of international standards, i.e. ASHRAE Standard 62.1 [1]. The proposed overall IEQ acceptance findings in residential buildings show CO2 concentration level between 909 and 1250 ppm. However, this may be considered a higher level of CO2 concentration, which may require increasing ventilation rate through window operation or mechanical ventilation.展开更多
Air quality was measured inside 628 United Arab Emirates (UAE) personal residences. Weekly average concentrations of carbon monoxide (CO), formaldehyde (HCHO), hydrogen sulfide (H2S), nitrogen dioxide (NO2), sulfur di...Air quality was measured inside 628 United Arab Emirates (UAE) personal residences. Weekly average concentrations of carbon monoxide (CO), formaldehyde (HCHO), hydrogen sulfide (H2S), nitrogen dioxide (NO2), sulfur dioxide (SO2), and three size fractions of particulate matter (PM2.5, PMc, and PM10) were determined in each home. In a subset of the homes, measurements of outdoor air quality, ultrafine PM concentrations, and elemental PM concentrations were also made. Questionnaires were administered to obtain information on housing demographics and lifestyle habits. Air measurements were performed using simple and cost effective passive samplers. The 90th percentiles of indoor CO, HCHO, H2S, NO2, and SO2 were 1.55 ppm, 0.05 ppm, 0.12 ppm, 0.01 ppm, and 0.05 ppm, respectively. Median indoor PM2.5, PMc, and PM10, concentrations were 5.73 μg/m3, 29.4 μg/m3, and 35.2 μg/m3, respectively. The median indoor concentration of ultrafine PM was 3.62 × 1010 particles/m3. Indoor/outdoor ratios for PM were 0.44, 0.41, and 0.38 for ultrafine PM, PM2.5, and PM10, respectively. These values fall within the range of other indoor air studies findings conducted in developing countries. Air conditioning, smoking, and attached kitchens were significantly correlated with indoor levels of carbon monoxide. In addition, indoor concentrations of PM2.5 and PM10 were significantly correlated with vehicles parked within five meters of the home, central air conditioning, and having attached kitchens. This is the first robust indoor air quality data set developed for the UAE. This study demonstrates that screening level tools are a good initial step for assessing air quality when logistical issues (distance, language, cultural, training) and intrusion into personal lives need to be minimized.展开更多
The present paper presents a numerical analysis of the difference in comfort level inside a room of a residential building when roof top turbine ventilator is installed. This analysis simulates various comfort factors...The present paper presents a numerical analysis of the difference in comfort level inside a room of a residential building when roof top turbine ventilator is installed. This analysis simulates various comfort factors which includes the indoor air movement, room temperature, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD). Various test cases of ventilator exhaust rate were examined. The results showed that general comfort satisfying international standards in building can be achieved. This study also presents a qualitative and quantitative study of indoor air temperature and overall indoor air flow pattern. A promising conclusion that can be drawn from this study is that wind driven ventilators can play an important role in the design of a cost effective and energy efficient ventilation system inside a building.展开更多
Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This ...Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This includes protection from airborne pathogens, such as tuberculosis, RSV, SARS-CoV-2, common cold or influenza viruses, measles, and others. Engineering controls are highly effective at reducing hazardous pathogens found in indoor air and from recontamination of surfaces. This occurs from a continuous cycle of settling of small, sustained airborne pathogens, which may become dehumidified, becoming airborne again, carried by room air currents around indoor spaces, then repeating the cycle. Methods: The novel technology utilizes a catalytic process to produce safe levels of hydrogen peroxide gas that are effective in reducing pathogens in the air and on surfaces. Air testing was performed with the MS2 bacteriophage, the test organism for ASHRAE standard 241, and methicillin-Resistant Staphylococcus aureus (MRSA). Surface testing was performed with SARS-COV-2 (Coronavirus COVID-19) and H1N1 (Influenza). Typical ventilation and filtration does not effectively remove disbursed pathogens from the entire facility, due to inconsistent air circulation and surface deposits of pathogens. Results: MS2 was reduced by 99.9%;MRSA was reduced by 99.9%;SARS-CoV-2 was reduced by 99.9%;H1N1 was reduced by 99.9%. Conclusion: This novel catalytic converter reduces a variety of pathogens in the air (99%) and on surfaces (99%), by actively disinfecting with the introduction of gaseous hydrogen peroxide. This active disinfection provides a strong solution for protecting the entire facility and its occupants.展开更多
The most hazardous chemical used in fiber glass industry are: formaldehyde, phenol and ammonia. The chemicals were monitored in an industry in Kuwaitto investigate the indoor air quality of the facility. It was found ...The most hazardous chemical used in fiber glass industry are: formaldehyde, phenol and ammonia. The chemicals were monitored in an industry in Kuwaitto investigate the indoor air quality of the facility. It was found that all these chemicals were within the OSHA standards but formaldehyde exceeded KEPA standards (0.1 ppm) in the curing area. It was found that lower density of fiber glass product leads to higher concentration of pollutants in the atmosphere andvise versa. Moreover, higher thickness causes higher concentration of pollutants in the atmosphere.展开更多
The study was conducted to identify indoor air quality and the level of thermal comfort in various selected locations in Faculty of Engineering and Built Environment （FKAB）, University Kebangsaan Malaysia （UKM） wi...The study was conducted to identify indoor air quality and the level of thermal comfort in various selected locations in Faculty of Engineering and Built Environment （FKAB）, University Kebangsaan Malaysia （UKM） with built-up area of 250,936 fie. The indoor air quality and thermal comfort were measured at various selected locations by using indoor air quality equipment （Thermal Comfort SERI）. The thermal comfort assessments are based on Malaysian Code of Practice Indoor Air Quality 2005 and Moderate Thermal Environments-Determination of the PMV and PPD indices specification of the condition for thermal comfort （ISO7730：1994） From the data analysis, the FKAB building is considered inadequately vented space. The concentration of CO2 for all sampling area evaluated exceeds the recommended concentration （〉 1000 ppm）. The ventilation system used in FKAB building is designed by delivering fix amount of fresh air into building from external building without consideration on the number of occupants. This common ventilation design will increase the amount of CO2 dramatically all day long and these reflect the inefficiency of energy used. The faculty needs to be equipped with a comprehensive energy management system that can allow detailed documentation of continuous performance of all energy system and consumption in the building.展开更多
Latvian children under the age of 7 can spend up to 60 hours per week in daycare centers and therefore it is very important to establish a healthy and comfortable daycare environment that children will find pleasant a...Latvian children under the age of 7 can spend up to 60 hours per week in daycare centers and therefore it is very important to establish a healthy and comfortable daycare environment that children will find pleasant and stimulating to stay in. This study investigates indoor air quality and thermal comfort within six daycare centers （old, renovated and new-built） in moderate climate zone of Latvia. Measurements of carbon dioxide, air temperature and relative humidity were carried out, and data regarding daycare center characteristics and maintenance activities was collected via combination of field visits, record analysis and interviews. It was found that carbon dioxide concentrations exceeded 1000 ppm in 75% of daycare centers studied, with the highest （1356 ppm） measured in a renovated facility with the natural ventilation system. Thus installation of more efficient ventilation system （mechanical） is recommended to provide acceptable indoor air quality, since opening of windows itself cannot provide the optimal conditions indoors. In all facilities the temperature was kept above 20℃ and the average relative humidity was 40±35%, creating comfortable thermal environment for children.展开更多
This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemica...This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemical,and biological methods to ascertain their effectiveness in formaldehyde mitigation.Physical methods,including air circulation and adsorption,particularly with activated carbon and molecular sieves,are assessed for their efficiency in various concentration scenarios.Chemical methods,such as photocatalytic oxidation using titanium dioxide and plasma technology,are analyzed for their ability to decompose formaldehyde into non-toxic substances.Additionally,biological methods involving plant purification and microbial transformation are explored for their eco-friendly and sustainable removal capabilities.The paper concludes that while each method has its merits,a combined approach may offer the most effective solution for reducing indoor formaldehyde levels.The study underscores the need for further research to integrate these methods in a practical,cost-effective,and environmentally sustainable manner,highlighting their potential to improve indoor air quality significantly.展开更多
INTRODUCTION Americans spend the majority of their time indoors where levels of pollutants may run two to five times-and occasionally more than 100 times-higher than outdoor levels[1].Many of these pollutants can caus...INTRODUCTION Americans spend the majority of their time indoors where levels of pollutants may run two to five times-and occasionally more than 100 times-higher than outdoor levels[1].Many of these pollutants can cause adverse health reactions in building occupants,which can contribute to lower worker productivity and increased sick leave.Traditional methods of indoor pollutant control in sealed buildings involve the use of outdoor ventilation.Outdoor ventilation requires the intake of outdoor air,which must be heated or cooled to meet indoor temperature and humidity requirements.This represents between 10-20%of the total energy consumption of a building[2].展开更多
As infectious respiratory diseases are highly transmissible through the air,researchers have improved traditional total volume air distribution systems to reduce infection risk.Multi-vent module-based adaptive ventila...As infectious respiratory diseases are highly transmissible through the air,researchers have improved traditional total volume air distribution systems to reduce infection risk.Multi-vent module-based adaptive ventilation(MAV)is a novel ventilation type that facilitates the switching of inlets and outlets to suit different indoor scenarios without changing ductwork layout.However,little research has evaluated MAV module sizing and air velocity selection,both related to MAV system efficiency in removing contaminants and the corresponding level of protection for occupants in the ventilated room.Therefore,the module-source offset ratio(MSOR)is proposed,based on the MAV module size and its distance from an infected occupant,to inform selection of optimal MAV module parameters.Computational fluid dynamics simulations illustrated contaminant distribution in a two-person MAV equipped office.Discrete phase particles modelled respiratory contaminants from the infected occupant,and contaminant concentration distributions were compared under four MAV air distribution layouts,three air velocities,and three module sizes considered using the MsOR.Results indicate that lower air velocities favour rising contaminant levels,provided the ventilation rate is met.Optimal contaminant discharge can be achieved when the line of outlets is located directly above the infected occupant.Using this parameter to guide MAV system design,85.7% of contaminants may be rendered harmless to the human body within 120 s using the default air vent layout.A more appropriate supply air velocity and air vent layout increases this value to 91.4%.These results are expected to inform the deployment of MAV systems to reduce airborne infection risk.展开更多
基金supported by the Project“Entrepreneurial competences and excellence research in doctoral and postdoctoral programs-ANTREDOC”,project cofounded by the European Social Fund financing agreement No.56437/24.07.2019.
文摘The amount of moisture in the air is represented by relative humidity(RH);an ideal level of humidity in the interior environment is between 40%and 60%at temperatures between 18°and 20°Celsius.When the RH falls below this level,the environment becomes dry,which can cause skin dryness,irritation,and discomfort at low temperatures.When the humidity level rises above 60%,a wet atmosphere develops,which encourages the growth of mold and mites.Asthma and allergy symptoms may occur as a result.Human health is harmed by excessive humidity or a lack thereof.Dehumidifiers can be used to provide an optimal level of humidity and a stable and pleasant atmosphere;certain models disinfect and purify the water,reducing the spread of bacteria.The design and implementation of a client-server indoor and outdoor air quality monitoring application are presented in this paper.The Netatmo station was used to acquire the data needed in the application.The client is an Android application that allows the user to monitor air quality over a period of their choosing.For a good monitoring process,the Netatmo modules were used to collect data from both environments(indoor:temperature(T),RH,carbon dioxide(CO_(2)),atmospheric pressure(Pa),noise and outdoor:T and RH).The data is stored in a database,using MySQL.The Android application allows the user to view the evolution of the measured parameters in the form of graphs.Also,the paper presents a prediction model of RH using Azure Machine Learning Studio(Azure ML Studio).The model is evaluated using metrics:Mean Absolute Error(MAE),Root Mean Squared Error(RMSE),Relative Absolute Error(RAE),Relative Squared Error(RSE)and Coefficient of Determination(CoD).
文摘Besides the need for low-cost instruments for air pollution measurement and detection,nowadays there are many concerns about air pollution due to the fast changes and used technologies.This research was applied using an MQ2 gas detector,and microcontroller/Arduino-Uno.The design steps included bonding and connecting readymade sensors,coding,and finally testing the device.Testing has been conducted in Environment and Pollution Engineering Department laboratories,at the Technical Engineering College of Kirkuk.This study proposed the use of an MQ2 sensor for multi-gas rate detection which can exist indoors.The system uses also a DHT22 sensor for measuring environment temperature and humidity.The sensors are connected to Arduino and LCD to present data on LCD by powering the system with external power.Overall,the testing was conducted,and the device served as a measuring tool for indoor air as an accurate multi-gas rate detector.
基金The National Natural Science Foundation of China(No.50878078)
文摘To study the indoor air qualities（IAQ）of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,is investigated.A questionnaire survey and field tests are used to collect data.According to the data of twelve rooms in this building,objective evaluation and the subjective evaluation of the IAQ are obtained.Almost all of the environmental parameters in these rooms basically meet the standards of the objective evaluation.But the average concentration of carbon dioxide in most rooms cannot reach the value of the cleanliness standards,1 255 mg/m^3.The average acceptability of the IAQ in these rooms is 71%,which is lower than the value of the ASHRAE 55—1992 standards,80%.The proper increase in the wind speed and the indoor fresh air supply can greatly improve the objective evaluation and the subjective evaluation of the IAQ.
文摘2022 Indoor Air Quality(IAQ),particularly in educational facilities,is gaining considerable interest and is a synonymous indicator towards evaluating human comfort.Factors such as CO_(2) concentration,temperature,and humidity play crucial parts in determining an acceptable level of IAQ.Many studies have also demonstrated that the indoor air quality of classrooms affects students’concentration and performance.Today with the threat of a global pandemic,the demand of clean&fresh indoor air quality in education buildings is extremely intensive.This study focuses on investigating IAQ situations and changes in different typical functional spaces of a higher education building in the UK.CO_(2),temperature,and humidity data in various learning environment were monitored via data loggers during the winter.Associated with data monitoring,a set of questionnaires surveys were carried out to evaluate the user’s experience.The results of this study show that temperature and CO_(2) concentration in the classrooms was constantly higher than the government guidance on a daily basis.The analysis also shows that temperature and humidity increased with CO_(2) levels,but at a much lower rate.This study has revealed poor and concerning IAQ in higher education buildings in the UK,particularly in larger rooms with high occupancy.Along with the findings,this paper also identifies possible impact or factors and proposes solutions to overcome these issues.
基金Project(2006BAJ02A10) supported by the National Key Technologies R & D Program of China
文摘To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the distribution of the indicators of indoor air in the gymnasium to check the air-conditioning parameters reasonable or not. And there was a questionnaire for audiences and staff about the acceptance and satisfaction of the thermal comfort,simultaneously,some environmental parameters were monitored. Then an experiment was carried out in gymnasium with the plate sedimentation to the biological aerosol in the air. Finally,the thermal comfort and IAQ in the gymnasium were assessed based on the results of above questionnaire survey and measurements. The results show that most parameters of the environmental are within the standard limits of thermal comfort and IAQ in the monitored period,and the biological contaminants initially come from human beings. The main species in the gymnasium are streptobacillus,coccus,cladosporium,penicillium and neurospora.
文摘Environmental monitoring of airborne formaldehyde (FA) using sensitive methodologies is fundamental to prevent health risks. The objective of this study was to compare three different FA monitoring methods during the daily activities of an anatomic pathology laboratory. Daily eight-hour measurements deriving from Radiello® passive diffusive samplers (PDS), NEMo XT continuous optical sensor (COS), and multi-gas 1512 photoacoustic monitor (MPM) were simultaneously compared over a period of 14 working days. Given the different daily distributions of the measurements performed by the three devices, all measurements were time-aligned for comparison purposes. The 95% limit of agreement (LOA) method was applied to estimate the degree of concordance of each device with respect to the others. Formaldehyde arithmetic mean measured using PDS was 32.6 ± 10.4 ppb (range: 19.8 - 62.7). The simultaneous measures performed by COS and MPM were respectively 42.4 ± 44.8 ppb (range: 7.0 - 175.0) and 189.0 ± 163.7 ppb (range: 40.0 - 2895.4). The MPM geometric mean (171.3 ppb) was approximately five times higher than those derived from COS (32.3 ppb) and PDS (31.4 ppb). The results of the LOA method applied to log-transformed FA data showed the same systematic discrepancies between MPM and the other two devices. A good agreement between PDS and COS could lead to a tailored approach according to the individual specificity of these techniques. This tool may be useful for accurately assessing the risk of FA exposure among healthcare workers. However, the limited specificity of the MPM does not support its use as a monitoring method for FA in the workplace.
文摘Increasing incidents of indoor air quality(IAQ) related complaints lead us to the fact that IAQ has become a significant occupational health and environmental issue. However, how to effectively evaluate IAQ under different scale of multiple indicators is still a challenge. The traditional single-indicator method is subjected to uncertainties in assessing IAQ due to different subjectivity on good or bad quality and scalar differences of data set. In this study, a multilevel integrated weighted average IAQ method including initial walking through assessment(IWA) and two-layers weighted average method are developed and applied to evaluate IAQ of the laboratory building at the University of Regina in Canada. Some important chemical parameters related to IAQ in terms of volatile organic compounds(VOCs), methanol(HCHO), carbon dioxide(CO2), and carbon monoxide(CO) are evaluated based on 5 months continuous monitoring data. The new integrated assessment result can not only indicates the risk of an individual parameter, but also able to quantify the overall IAQ risk on the sampling site. Finally, some recommendations based on the result are proposed to address sustainable IAQ practices in the sampling area.
文摘Providing comfortable indoor air quality control in residential construction is an exceedingly important issue.This is due to the structure of the fast response controller of air quality.The presented work shows the breakdown and creation of a mathematical model for an interactive,nonlinear system for the required comfortable air quality.Furthermore,the paper refers to designing traditional proportional integral derivative regulators and proportional,integral,derivative regulators with independent parameters based on a backpropagation neural network.In the end,we perform the experimental outputs of a suggested backpropagation neural network-based proportional,integral,derivative controller and analyze model results by applying the proposed system.The obtained results demonstrated that the proposed controller can provide the required level of clean air in the room.The proposed developed model takes into consideration international Heating,Refrigerating,and air conditioning standards as ASHRAE AND ISO.Based on the findings,we concluded that it is possible to implement a proposed system in homes and offer equivalent indoor air quality with continuous mechanical ventilation without a profuse amount of energy.
文摘Indoor air environment includes indoor thermal environment and air quality, and a reasonable ventilation provides guarantee for a good indoor environment. A numerical study of the indoor environment in different ventilation is presented in this paper. The External Energy Saving Lab of the WenYuan Building was selected for this purpose, and its indoor air quality and thermal performance in the typical summer climate were simulated. For the numerical simulation, the techniques of Fluent Air-pak was adopted to establish the physical and numerical model of lab. A attention is given to the velocity field and the distribution of pollutant concentration, followed by a discussion of two ventilation modes (displacement ventilation and up-in and up-out ventilation). By comparison, it is found that the Displacement ventilation in improving indoor air quality is obviously superior to the traditional up-in and up-out ventilation.
文摘In this study, the indoor environmental quality (IEQ) in air conditioned residential buildings in a dry desert climate is examined from the perspective of occupants via two aspects: thermal comfort and indoor air quality. The study presents statistical data about the domestic-occupant thermal comfort sensations together with data describing the indoor air quality in Kuwaiti residential buildings. With respect to the latter, the overall IEQ acceptance using two measurements namely: physical measurements and subjective information collected via questionnaires, was used to evaluate 111 occupants living in twenty five air-conditioned residential buildings in the state of Kuwait. The operative temperature based on Actual Mean Vote (AMV) and Predicted Mean Vote (PMV) was identified using linear regression analysis of responses on the ASHRAE seven-point thermal sensation scale and was found to be 25.2°C and 23.3°C, respectively, in the summer season. Indoor air quality (IAQ) with respect to carbon dioxide concentration level was compared with the acceptable limits of international standards, i.e. ASHRAE Standard 62.1 [1]. The proposed overall IEQ acceptance findings in residential buildings show CO2 concentration level between 909 and 1250 ppm. However, this may be considered a higher level of CO2 concentration, which may require increasing ventilation rate through window operation or mechanical ventilation.
文摘Air quality was measured inside 628 United Arab Emirates (UAE) personal residences. Weekly average concentrations of carbon monoxide (CO), formaldehyde (HCHO), hydrogen sulfide (H2S), nitrogen dioxide (NO2), sulfur dioxide (SO2), and three size fractions of particulate matter (PM2.5, PMc, and PM10) were determined in each home. In a subset of the homes, measurements of outdoor air quality, ultrafine PM concentrations, and elemental PM concentrations were also made. Questionnaires were administered to obtain information on housing demographics and lifestyle habits. Air measurements were performed using simple and cost effective passive samplers. The 90th percentiles of indoor CO, HCHO, H2S, NO2, and SO2 were 1.55 ppm, 0.05 ppm, 0.12 ppm, 0.01 ppm, and 0.05 ppm, respectively. Median indoor PM2.5, PMc, and PM10, concentrations were 5.73 μg/m3, 29.4 μg/m3, and 35.2 μg/m3, respectively. The median indoor concentration of ultrafine PM was 3.62 × 1010 particles/m3. Indoor/outdoor ratios for PM were 0.44, 0.41, and 0.38 for ultrafine PM, PM2.5, and PM10, respectively. These values fall within the range of other indoor air studies findings conducted in developing countries. Air conditioning, smoking, and attached kitchens were significantly correlated with indoor levels of carbon monoxide. In addition, indoor concentrations of PM2.5 and PM10 were significantly correlated with vehicles parked within five meters of the home, central air conditioning, and having attached kitchens. This is the first robust indoor air quality data set developed for the UAE. This study demonstrates that screening level tools are a good initial step for assessing air quality when logistical issues (distance, language, cultural, training) and intrusion into personal lives need to be minimized.
文摘The present paper presents a numerical analysis of the difference in comfort level inside a room of a residential building when roof top turbine ventilator is installed. This analysis simulates various comfort factors which includes the indoor air movement, room temperature, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD). Various test cases of ventilator exhaust rate were examined. The results showed that general comfort satisfying international standards in building can be achieved. This study also presents a qualitative and quantitative study of indoor air temperature and overall indoor air flow pattern. A promising conclusion that can be drawn from this study is that wind driven ventilators can play an important role in the design of a cost effective and energy efficient ventilation system inside a building.
文摘Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This includes protection from airborne pathogens, such as tuberculosis, RSV, SARS-CoV-2, common cold or influenza viruses, measles, and others. Engineering controls are highly effective at reducing hazardous pathogens found in indoor air and from recontamination of surfaces. This occurs from a continuous cycle of settling of small, sustained airborne pathogens, which may become dehumidified, becoming airborne again, carried by room air currents around indoor spaces, then repeating the cycle. Methods: The novel technology utilizes a catalytic process to produce safe levels of hydrogen peroxide gas that are effective in reducing pathogens in the air and on surfaces. Air testing was performed with the MS2 bacteriophage, the test organism for ASHRAE standard 241, and methicillin-Resistant Staphylococcus aureus (MRSA). Surface testing was performed with SARS-COV-2 (Coronavirus COVID-19) and H1N1 (Influenza). Typical ventilation and filtration does not effectively remove disbursed pathogens from the entire facility, due to inconsistent air circulation and surface deposits of pathogens. Results: MS2 was reduced by 99.9%;MRSA was reduced by 99.9%;SARS-CoV-2 was reduced by 99.9%;H1N1 was reduced by 99.9%. Conclusion: This novel catalytic converter reduces a variety of pathogens in the air (99%) and on surfaces (99%), by actively disinfecting with the introduction of gaseous hydrogen peroxide. This active disinfection provides a strong solution for protecting the entire facility and its occupants.
文摘The most hazardous chemical used in fiber glass industry are: formaldehyde, phenol and ammonia. The chemicals were monitored in an industry in Kuwaitto investigate the indoor air quality of the facility. It was found that all these chemicals were within the OSHA standards but formaldehyde exceeded KEPA standards (0.1 ppm) in the curing area. It was found that lower density of fiber glass product leads to higher concentration of pollutants in the atmosphere andvise versa. Moreover, higher thickness causes higher concentration of pollutants in the atmosphere.
文摘The study was conducted to identify indoor air quality and the level of thermal comfort in various selected locations in Faculty of Engineering and Built Environment （FKAB）, University Kebangsaan Malaysia （UKM） with built-up area of 250,936 fie. The indoor air quality and thermal comfort were measured at various selected locations by using indoor air quality equipment （Thermal Comfort SERI）. The thermal comfort assessments are based on Malaysian Code of Practice Indoor Air Quality 2005 and Moderate Thermal Environments-Determination of the PMV and PPD indices specification of the condition for thermal comfort （ISO7730：1994） From the data analysis, the FKAB building is considered inadequately vented space. The concentration of CO2 for all sampling area evaluated exceeds the recommended concentration （〉 1000 ppm）. The ventilation system used in FKAB building is designed by delivering fix amount of fresh air into building from external building without consideration on the number of occupants. This common ventilation design will increase the amount of CO2 dramatically all day long and these reflect the inefficiency of energy used. The faculty needs to be equipped with a comprehensive energy management system that can allow detailed documentation of continuous performance of all energy system and consumption in the building.
文摘Latvian children under the age of 7 can spend up to 60 hours per week in daycare centers and therefore it is very important to establish a healthy and comfortable daycare environment that children will find pleasant and stimulating to stay in. This study investigates indoor air quality and thermal comfort within six daycare centers （old, renovated and new-built） in moderate climate zone of Latvia. Measurements of carbon dioxide, air temperature and relative humidity were carried out, and data regarding daycare center characteristics and maintenance activities was collected via combination of field visits, record analysis and interviews. It was found that carbon dioxide concentrations exceeded 1000 ppm in 75% of daycare centers studied, with the highest （1356 ppm） measured in a renovated facility with the natural ventilation system. Thus installation of more efficient ventilation system （mechanical） is recommended to provide acceptable indoor air quality, since opening of windows itself cannot provide the optimal conditions indoors. In all facilities the temperature was kept above 20℃ and the average relative humidity was 40±35%, creating comfortable thermal environment for children.
文摘This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemical,and biological methods to ascertain their effectiveness in formaldehyde mitigation.Physical methods,including air circulation and adsorption,particularly with activated carbon and molecular sieves,are assessed for their efficiency in various concentration scenarios.Chemical methods,such as photocatalytic oxidation using titanium dioxide and plasma technology,are analyzed for their ability to decompose formaldehyde into non-toxic substances.Additionally,biological methods involving plant purification and microbial transformation are explored for their eco-friendly and sustainable removal capabilities.The paper concludes that while each method has its merits,a combined approach may offer the most effective solution for reducing indoor formaldehyde levels.The study underscores the need for further research to integrate these methods in a practical,cost-effective,and environmentally sustainable manner,highlighting their potential to improve indoor air quality significantly.
文摘INTRODUCTION Americans spend the majority of their time indoors where levels of pollutants may run two to five times-and occasionally more than 100 times-higher than outdoor levels[1].Many of these pollutants can cause adverse health reactions in building occupants,which can contribute to lower worker productivity and increased sick leave.Traditional methods of indoor pollutant control in sealed buildings involve the use of outdoor ventilation.Outdoor ventilation requires the intake of outdoor air,which must be heated or cooled to meet indoor temperature and humidity requirements.This represents between 10-20%of the total energy consumption of a building[2].
基金supported by the National Natural Science Foundation of China[No.52078009]the special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control[No.BZ0344KF20-05]the joint research project of the Wind Engineering Research Center,Tokyo Polytechnic University(MEXT(Japan)Promotion of Distinctive Joint ResearchCenter Program)[No.JPMXP0619217840,No.JURC20202007].
文摘As infectious respiratory diseases are highly transmissible through the air,researchers have improved traditional total volume air distribution systems to reduce infection risk.Multi-vent module-based adaptive ventilation(MAV)is a novel ventilation type that facilitates the switching of inlets and outlets to suit different indoor scenarios without changing ductwork layout.However,little research has evaluated MAV module sizing and air velocity selection,both related to MAV system efficiency in removing contaminants and the corresponding level of protection for occupants in the ventilated room.Therefore,the module-source offset ratio(MSOR)is proposed,based on the MAV module size and its distance from an infected occupant,to inform selection of optimal MAV module parameters.Computational fluid dynamics simulations illustrated contaminant distribution in a two-person MAV equipped office.Discrete phase particles modelled respiratory contaminants from the infected occupant,and contaminant concentration distributions were compared under four MAV air distribution layouts,three air velocities,and three module sizes considered using the MsOR.Results indicate that lower air velocities favour rising contaminant levels,provided the ventilation rate is met.Optimal contaminant discharge can be achieved when the line of outlets is located directly above the infected occupant.Using this parameter to guide MAV system design,85.7% of contaminants may be rendered harmless to the human body within 120 s using the default air vent layout.A more appropriate supply air velocity and air vent layout increases this value to 91.4%.These results are expected to inform the deployment of MAV systems to reduce airborne infection risk.
