Indoor Environment Quality Monitoring and Evaluation System Based on LoRa Communication

Indoor environmental quality has always been the focus of people’s long-term attention. How to monitor the indoor environmental level conveniently and accurately is a problem that people pay attention to now. After research, an indoor environment level monitoring system based on LoRa communication is designed. The system is mainly divided into two parts, the detection node, and the monitoring terminal. Temperature, humidity, light intensity, noise, formal-dehyde, and carbon dioxide are detected through the node with STM32F103ZET6 microcontroller as the controller;the data is sent to the monitoring terminal for display through LoRa communication. At the same time, the T-S fuzzy neural network (TSFNN) is improved by the particle swarm optimization (PSO) algorithm to classify the indoor environment quality level. Experimental test: the total error of the improved TSFNN model test set is reduced by 8.6007. The system can monitor the indoor environment level objectively and reliably, and has high practical value.

The integration model of objective and subjective data of residential indoor environment quality in Northeast China based on structural equation modeling

Currently the indoor environment quality is described or evaluated mainly by the subjective or objective data.However,research increasingly has demonstrated that objective and subjective data both had some weaknesses to characterize the indoor environment quality,and they can compensate for each other's relative weaknesses.Hence,this study aims to develop an integration model to allow indoor subjective and objective data to be combined based on the structural equation modeling approach,using the Northeast China residential indoor environmental survey data.The results indicated that the integration model had a good fit for the survey data,and the model validity was confirmed.Moreover,in contrast to the subjective data(R^(2)=0.363)and objective data(R^(2)=0.239),the integrated data(R^(2)=0.553)improved the explanatory power on the satisfaction with the overall indoor environment.Furthermore,this integration model demonstrated that indoor subjective data assigned more weights to the integrated data than the corresponding objective data.The association strength of thermal environment and indoor air quality(0.43 or 0.47)was the strongest among the interactions of thermal,air quality,acoustic,and lighting environments.Consequently,the main contribution of this paper was that it provided a comprehensive model to accomplish the integration of indoor environmental subjective and objective data,promoting the ability to describe and assess the indoor environment quality.

Energy consumption,indoor environmental quality,and benchmark for office buildings in Hainan Province of China

With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79% of the total energy consumption,natural gas 0.17%,and diesel 0.04%.The air conditioning dominated the energy use with a share of 43.18%,equipment in the particular areas 26.90%,equipment in the office rooms 11.95%,lighting system 8.67%,general service system 7.57%,and miscellaneous items 1.73%.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW-h/m2 and lower limit of 55.26 kW-h/m2.According to ASHRAE standard(comfortable standard) and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92% of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio.

THE INDOOR ENVIRONMENTAL QUALITY PERFORMANCE OF GREEN LOW-INCOME SINGLE-FAMILY HOUSING

There is little empirical evidence in the literature about the indoor environmental quality performance of residential buildings in general and of social housing in particular. To address this problem, this study used a mixed-method approach to evaluate the indoor environmental quality performance of 17 green low-income single attached family houses in Brandon, Manitoba, Canada. Questionnaires were administered to occupants to assess their snapshot and long-term satisfaction with the indoor environment. In addition, snapshot measurements were carried out to evaluate the indoor environmental quality factors of thermal comfort, indoor air quality, lighting and acoustics. Occupants’ snapshot satisfaction was categorized into two groups (i.e. satisfied/comfortable or dissatisfied/uncomfortable) and compared with snapshot measurements. The results showed the measured IEQ parameters were well below recommended threshold levels. Further, occupants with higher snapshot satisfaction were generally exposed to relatively lower levels of indoor pollutants. A statistically significant difference was found in PM10 level only between the snapshot satisfied and snapshot dissatisfied groups of occupants. Apparent sound transmission classes were below the standard reference value of 50, suggesting potential problems in noise attenuation within different spaces in each apartment and between apartments. The findings of this study could help governments implement green shadowing for public-housing and also renovate existing houses using the same principles.

ASSESSMENT OF EFFECTIVE ENERGY RETROFIT STRATEGIES AND RELATED IMPACT ON INDOOR ENVIRONMENTAL QUALITY A case study of an elementary school in the State of Maryland

1.0.INTRODUCTION In the United States,K-12 school buildings spend more than$8 billion each year on energy-more than they spend on computers and textbooks combined[1].Most occupied older buildings demonstrate poor operational performance-for instance,more than 30 percent of schools were built before 1960,and 53 percent of public schools need to spend money on repairs,renovations,and modernization to ensure that the schools’onsite buildings are in good overall condition.And among public schools with permanent buildings,the environmental factors in the permanent buildings have been rated as unsatisfactory or very unsatisfactory in 5 to 17 percent of them[2].Indoor environment quality(IEQ)is one of the core issues addressed in the majority of sustainable building certification and design guidelines.Children spend a significant amount of time indoors in a school environment.And poor IEA can lead to sickness and absenteeism from school and eventually cause a decrease in student performance[3].Different building types and their IEQ characteristics can be partly attributed to building age and construction materials.[4]Improving the energy performance of school buildings could result in the direct benefit of reduced utility costs and improving the indoor quality could improve the students’learning environment.Research also suggests that aging school facilities and inefficient equipment have a detrimental effect on academic performance that can be reversed when schools are upgraded.[5]Several studies have linked better lighting,thermal comfort,and air quality to higher test scores.[6,7,8]Another benefit of improving the energy efficiency of education buildings is the potential increase in market value through recognition of green building practice and labeling,such as that of a LEED or net zero energy building.In addition,because of their educational function,high-performance or energy-efficient buildings are particularly valuable for institution clients and local government.More and more high-performance buildings,net zero energy buildings,and positive energy buildings serve as living laboratories for educational purposes.Currently,educational/institutional buildings represent the largest portion of NZE(net zero energy)projects.Educational buildings comprise 36 percent of net zero buildings according to a 2014 National New Building Institute report.Of the 58 net zero energy educational buildings,32 are used for kindergarten through grade 12(K-12),21 for higher education,and 5 for general education.[9]Finally,because educational buildings account for the third largest amount of building floor space in the United States,super energy-efficient educational buildings could provide other societal and economic benefits beyond the direct energy cost savings for three reasons:1)educational buildings offer high visibility that can influence community members and the next generation of citizens,2)success stories of the use of public funds that returns lower operating costs and healthier student learning environments provide documentation that can be used by others,and 3)this sector offers national and regional forums and associations to facilitate the transfer of best design and operational practices.

Indoor Environmental Requirements in Green Building in Jordan

The aim of this study is to provide stimulating and comfortable environments for the occupants and minimize the risk of green building related health problems. Researcher has developed a number of assumptions that helps to resolve the research problems, which includes the application of the indoor environmental quality and will highlight the required design standards of it to provide a healthy environment to the houses and chosen AREE （Aqaba residence energy efficiency） as a case study. The theoretical part goes through a brief study to definition of the required design standards which includes eight kinds of issues： indoor environmental quality intents, control of environmental tobacco smoke, control of chemicals contaminants, design well ventilated buildings, provide daylight/view, energy efficient lighting, thermal comfort, consider acoustics and its uses in all the elements of internal spaces. Than we going through the uses of these requirements by using descriptive analytical approach, we chose one case study （AREE）. To analyze the uses of their requirements of the indoor environmental quality and we also collect the information about this house from the owner of the AREE, then draw conclusions and list of references.

Behavior of the Cultivable Airborne Mycobiota in air-conditioned environments of three Havanan archives, Cuba

High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers'health.The aims of this work were to evaluate the behavior of the fungal concentration and diversity in the indoor air of repositories of 3 archives located in Havana,Cuba,and to demonstrate the potential risk that these taxa represent for the documentary heritage preserved in these institutions.The indoor and outdoor environments were sampled with a biocollector.From the I/O ratios,it was evident that two of the studied archives were not contaminated,while one of them did show contamination despite having temperature and relative humidity values very similar to the other two.Aspergillus,Penicillium and Cladosporium were the predominant genera in the indoor environments.New finds for archival environments were the genera Harposporium and Scolecobasidium.The principal species classified ecologically as abundant were C.cladosporioides and P.citrinum.They are known as opportunistic pathogenic fungi.All the analyzed taxa excreted acids,the most of them degraded cellulose,starch and gelatin while about 48%excreted different pigments.But 33%of them showed the highest biodeteriogenic potential,evidencing that they are the most dangerous for the documentary collections.

Machine Learning and Deep Learning Methods for Enhancing Building Energy Efficiency and Indoor Environmental Quality – A Review

The built environment sector is responsible for almost one-third of the world’s final energy consumption. Hence, seeking plausible solutions to minimise building energy demands and mitigate adverse environmental impacts is necessary. Artificial intelligence (AI) techniques such as machine and deep learning have been increasingly and successfully applied to develop solutions for the built environment. This review provided a critical summary of the existing literature on the machine and deep learning methods for the built environment over the past decade, with special reference to holistic approaches. Different AI-based techniques employed to resolve interconnected problems related to heating, ventilation and air conditioning (HVAC) systems and enhance building performances were reviewed, including energy forecasting and management, indoor air quality and occupancy comfort/satisfaction prediction, occupancy detection and recognition, and fault detection and diagnosis. The present study explored existing AI-based techniques focusing on the framework, methodology, and performance. The literature highlighted that selecting the most suitable machine learning and deep learning model for solving a problem could be challenging. The recent explosive growth experienced by the research area has led to hundreds of machine learning algorithms being applied to building performance-related studies. The literature showed that existing research studies considered a wide range of scope/scales (from an HVAC component to urban areas) and time scales (minute to year). This makes it difficult to find an optimal algorithm for a specific task or case. The studies also employed a wide range of evaluation metrics, adding to the challenge. Further developments and more specific guidelines are required for the built environment field to encourage best practices in evaluating and selecting models. The literature also showed that while machine and deep learning had been successfully applied in building energy efficiency research, most of the studies are still at the experimental or testing stage, and there are limited studies which implemented machine and deep learning strategies in actual buildings and conducted the post-occupancy evaluation.

Indoor environmental quality(IEQ)assessment of Nigerian university libraries:A pilot study

An indoor environmental quality(IEQ)assessment of academic libraries in Nigeria was conducted through ob-jective measurements.The selected university libraries were Abubakar Gimba Library;Awwal Ibrahim Library;and Ibrahim Badamosi Babangida Library Complex.The libraries were evaluated under operating conditions and during their peak usage periods.Measurements of the main descriptors of good IEQ,including the acoustical,visual,and thermal comfort conditions were performed using portable IEQ meters.The methodology employed for the assessment of these IEQ descriptors followed prescriptions of international standards ASHRAE standard 55 and ISO 7730.To determine the time of the day in which the library buildings can achieve optimum IEQ,measurements were taken in the morning and afternoon.The results obtained were compared with reference values found in the international Standard CIBSE Guide A for adequate IEQ compliance of academic libraries.The findings of this study are expected to help in improving the IEQ of academic libraries in Nigeria and other parts of the world.

Application of statistical analysis of sample size:How many occupant responses are required for an indoor environmental quality(IEQ)field study

Determining required sample size is one of the critical pathways to reproducible,reliable and robust results in human-related studies.This paper aims to answer a fundamental but often overlooked question:what sample size is required in surveys of occupant responses to indoor environmental quality(IEQ).The statistical models are introduced in order to promote determining required sample size for various types of data analysis methods commonly used in IEQ field studies.The Monte Carlo simulations are performed to verify the statistical methods and to illustrate the impact of sample size on the study accuracy and reliability.Several examples are presented to illustrate how to determine the value of the parameters in the statistical models based on previous similar research or existing databases.The required sample size including“worst”and“optimal”cases in each condition is obtained by this method and references.It is indicated that 385 is a“worst case”sample size to be adequate for a subgroup analysis,while if the researcher has an estimate of the study design and outcome,the“optimal case”sample size can potentially be reduced.When the required sample size is not achievable,the uncertainty in the result can properly interpret via a confidence interval.It is hoped that this paper would fill in the gap between statistical analysis of sample size and IEQ field research,and it can provide a useful reference for researchers when planning their own studies.

AN INVESTIGATION INTO TENANT ORGANIZATIONS' WILLINGNESS-TO-PAY FOR THE INTANGIBLE VALUE-ADDED BENEFITS OF SUSTAINABLE BUILDINGS:CASE STUDY IN SINGAPORE

This research aims to understand the demand for sustainable buildings by inves-tigating the tenant organizations’willingness-to-pay(WTP)behavior towards the value-added benefits(VABs).Tenant organizations refer to tenants operating in office buildings on tenancy agreement.Six groups of factors of tenant organi-zations’WTP for the VABs are identified:(1)Organization Characteristics,(2)Current Premises,(3)Building Characteristics,(4)Satisfaction of the VABs Expe-rienced,(5)Perception,and(6)Knowledge of Sustainability Issues,Building Sus-tainability Rating Systems and Building Impacts.A survey was conducted on the tenant organizations operating in office buildings located in the city area of Singa-pore.The hypothesized relationship between the tenant organizations’WTP for the VABs and its factors were tested using a series of statistical techniques on the data collected from the survey.It is found that older tenant organizations tend to have lower WTP for the VABs of improved health and comfort of their employees.Generally,tenant organizations also have demand for sustainable buildings mainly due to the positive organizational image that sustainable buildings help to project.In addition,it is found that the current building sustainability rating systems are inadequate for communicating the sustainability benefits to building occupants and for achieving building sustainability.Lastly,the investigation reveals that the use of sustainable technologies is not as important as how the building is being managed during its operational stage for ensuring building sustainability performance.The findings from this study are useful for channeling the sustainability efforts of the building industry to more effective areas.

An Intelligent IEQ Monitoring and Feedback System:Development and Applications

Indoor environmental quality(IEQ)significantly affects human health and wellbeing.Therefore,continuous IEQ monitoring and feedback is of great concern in both the industrial and academic communities.However,most existing studies only focus on developing sensors that cost-effectively promote IEQ measurement while ignoring interactions between the human side and IEQ monitoring.In this study,an intelligent IEQ monitoring and feedback system-the Intelligent Built Enviroment(IBEM)-is developed.Firstly,the IBEM hardware instrument integrates air temperature,relative humidity,CO_(2),particulate matter with an aerodynamic diameter no greater than _(2.5)μm(PM_(2.5)),and illuminance sensors within a small device.The accuracy of this integrated device was tested through a co-location experiment with reference sensors;the device exhibited a strong correlation with the reference sensors,with a slight deviation(R^(2)>0.97 and slopes between 1.01 and 1.05).Secondly,a wireless data transmission module,a cloud storage module,and graphical user interfaces(i.e.,a web platform and mobile interface)were built to establish a pathway for dataflow and interactive feedback with the occupants of the indoor environments.Thus,the IEQ parameters can be continuously monitored with a high spatiotemporal resolution,interactive feedback can be induced,and synchronous data collection on occupant satisfaction and objective environmental parameters can be realized.IBEM has been widely applied in 131 buildings in 18cities/areas in China,with 1188 sample locations.Among these applications,we report on the targeted IEQ diagnoses of two individual buildings and the exploration of relationships between subjective and objective IEQ data in detail here.This work demonstrates the great value of IBEM in both industrial and academic research.

Improved indoor environment through optimised ventilator and furniture positioning:A case of slum rehabilitation housing,Mumbai,India

This study optimized the ventilator and furniture location of a tenement unit in a low-income urban habitat to obtain maximum experiential indoor environmental quality(e-IEQ)over the breathing zone.Hypothetical interior layouts using a combination of the two design parameters of ventilator location and bed position were generated for optimizing the design layout.This layout could promote maximum indoor airflow and minimum indoor air temperature and contaminant concentration.In this study,an improved indoor environment is hypothesized to be attainable through improved natural ventilation and thermal performance in the occupied zones.A sequential methodology involving“parametric design modeling ecomputational simulationemultiobjective optimizationemulticriteria decision making”-based framework was selected.Results exhibited that the currently designed tenement unit had a poor indoor environment,whereas the hypothesized iterated layout“optimized design layout,scenario 3(ODL 3)”derived from the optimization and decision-making algorithm performed effectively in providing e-IEQ.An increase in experiential indoor air velocity by 0.2 m/s and a decrease in temperature by 2C were observed over the monitoring point in the ODL 3 considering the existing scenario.Therefore,this study can find a way toward the development of sustainable habitat design guidelines under upcoming slum redevelopment policies across the nation.

POST-OCCUPANCY EVALUATION OF EMPLOYEES’WORK PERFORMANCE AND SATISFACTION AS RELATED TO SUSTAINABLE DESIGN CRITERIA AND WORKSTATION TYPE

This case study investigated employees’work performance and satisfaction in relation to sustainable design criteria used to design the interior of their office building.The case study is part of ongoing research to continue testing a questionnaire for validity and reliability,which will contribute to the development of sustainable design/occupant scales relating to satisfaction and performance.A self-administered,Internet-based questionnaire was developed that reflects a set of recognized sustainable design guidelines.It was submitted to over 200 employees of a business housed in a newly built office building in a mid-western city.Generally positive results were found for employees’satisfaction with the new facility(site,building,and interior)and their performance as related to sustainable design criteria in the new facility.Dissatisfaction with acoustic and privacy conditions were found for employees of open-office workstation types(cubicles).Exploration of prior workstation types showed that moving from private offices to cubicles decreased employees’satisfaction with new cubicles compared to moving from cubicles in a prior building to cubicles in the new building,though dissatisfaction with these two criteria was found despite prior workstation type.These findings concur with other sustainable design studies and demonstrate that the questionnaire can be used by sustainable designers to document and explore design outcomes.

DEVELOPING AN‘AS PERFORMING’BUILDING ASSESSMENT

The building profession is increasingly becoming more demanding with respect to building environmental perfor-mance.Intentions are to provide best practices into our buildings.In part,this is a response due to the Australian government and other independent organisations that have developed policy on rating tools and performance ranking measures,all with the intention of accomplishing environmentally sustainable buildings.With rating systems endorsing innovative environmental design solutions,it could be asked:Are our buildings re-ally operating as rated?Do we know whether our designs are in compliance with what was calculated or simulated?Is there a feedback loop informing the design process on successes or failures in our designs or mechanical services?While ratings continue to focus on‘by design’or‘as built’rewards,few tools acknowledge perhaps the more cru-cial bottom line:‘as performing’.With the exception of an AGBR(Australian Green Building Rating)scheme on actual annual energy consumption,there appears to be no‘as performing’assessment.Furthermore,practically every building is a prototype(a one-off)and requires commissioning,programming and scheduling of its services.It would certainly appear that as stakeholders(the procurers,owners,facilities managers and users)of the newly built environ-ment,that what we really want to know is actual on-site confirmation of performance.It is the objective of the Mobile Architecture and Built Environment Laboratory(MABEL),to provide such a service.

AlphaMobileSensing:A virtual testbed for mobile environmental monitoring

Environmental monitoring plays a critical role in creating and maintaining a comfortable,productive,and healthy environment.Built upon the advancements of robotics and data processing,mobile sensing demonstrates its potential to address problems regarding cost,deployment,and resolution that stationary monitoring encounters,which therefore has attracted increasing research attentions recently.To facilitate mobile sensing,two key algorithms are needed:the field reconstruction algorithm and the route planning algorithm.The field reconstruction algorithm is to reconstruct the entire environment field from spatially-and temporally-discrete measurements collected by the mobile sensors.The route planning algorithm is to instruct the mobile sensors where the mobile sensor needs to move to for the next measurements.The performance of mobile sensors highly depends on these two algorithms.However,developing and testing those algorithms in the real world is expensive,challenging,and time-consuming.To address these issues,we proposed and implemented an open-source virtual testbed,AlphaMobileSensing,that can be used to develop,test,and benchmark mobile sensing algorithms.AlphaMobileSensing aims to help users more easily develop and test the field reconstruction and route planning algorithms for mobile sensing solutions,without worrying about hardware fault,test accidents(such as collision during the test),etc.The separation of concerns can significantly reduce the cost of developing software solutions for mobile sensing.For versatility and flexibility,AlphaMobileSensing was wrapped up using the standardized interface of OpenAI Gym,and it also provides an interface for loading physical fields that were generated by numerical simulations as virtual test sites to perform mobile sensing and retrieving monitoring data.We demonstrated applications of the virtual testbed by implementing and testing algorithms for physical field reconstruction in both static and dynamic indoor thermal environments.AlphaMobileSensing provides a novel and flexible platform to develop,test,and benchmark mobile sensing algorithms more easily,conveniently,and efficiently.AlphaMobileSensing is open sourced at https://github.com/kishuqizhou/AlphaMobileSensing.

ENHANCING THERMAL COMFORT OF RESIDENTIAL BUILDINGS THROUGH A DUAL FUNCTIONAL PASSIVE SYSTEM (SOLAR-WALL)

Thermal comfort has a great impact on occupants’productivity and general well-being.Since people spend 80–90%of their time indoors,developing the tools and methods that enhance the thermal comfort for building are worth investigating.Previous studies have proved that using passive systems like Trombe walls and solar chimneys significantly enhanced thermal comfort in inside spaces despite that each system has a specific purpose within a specific climate condition.Hence,the main purpose of this study is to design and configure a new,dual functional passive system,called a solar wall.The new system combines the Trombe wall and solar chimney,and it can cool or heat based on building needs.Simulation software,DesignBuilder,has been used to configure the Solar Wall,and study its impact on indoor operative temperature for the base case.Using the new system,the simulation results were compared with those obtained in the base case and analyzed to determine the most efficient system design parameters and implementation method.The case that gave the best results for solar wall configuration was triple glazed glass and 0.1 cm copper as an absorber(case 11).The results show that using four units(case D)achieves longer thermal comfort levels:15 to 24 thermal hours during winter(compared to five hours maximum)and 10 to 19 comfort hours in summer(compared to zero).

ENHANCING THERMAL COMFORT OF RESIDENTIAL BUILDINGS THROUGH DUAL FUNCTIONAL PASSIVE SYSTEM(SOLAR-WALL)

Thermal comfort has a great effect on occupants’productivity and general well-being.Since people spend 80-90%of their time indoors,developing the tools and methods that help in enhancing the thermal comfort for buildings are worth investigating.Previous studies have proved that using passive systems like Trombe walls and solar chimneys significantly enhanced thermal comfort in inside spaces despite that each system has a specific purpose within a specific climate condition.Hence,the main purpose of this study is to design and configure a new dual functional passive system,called a solar wall.The new system combines the Trombe wall and solar chimney,and it can cool or heat based on building needs.Simulation software,DesignBuilder,has been used to configure the Solar Wall and study its impact on indoor operative temperature for the base case.Using the new system,the simulation results were compared with those obtained in the base case and analyzed to determine the most efficient system design parameters and implementation method.The case that gave the best results for solar wall configuration was triple glazed glass and 0.1 cm copper as an absorber(case 11).The results show that using four units(case D)achieves longer thermal comfort levels:15 to 24 thermal hours during winter(compared to five hours maximum)and 10 to 19 comfort hours in summer(compared to zero).

Extraction method of typical IEQ spatial distributions based on low-rank sparse representation and multi-step clustering

Indoor environment quality(IEQ)is one of the most concerned building performances during the operation stage.The non-uniform spatial distribution of various IEQ parameters in large-scale public buildings has been demonstrated to be an essential factor affecting occupant comfort and building energy consumption.Currently,IEQ sensors have been widely employed in buildings to monitor thermal,visual,acoustic and air quality.However,there is a lack of effective methods for exploring the typical spatial distribution of indoor environmental quality parameters,which is crucial for assessing and controlling non-uniform indoor environments.In this study,a novel clustering method for extracting IEQ spatial distribution patterns is proposed.Firstly,representation vectors reflecting IEQ distributions in the concerned space are generated based on the low-rank sparse representation.Secondly,a multi-step clustering method,which addressed the problems of the“curse of dimensionality”,is designed to obtain typical IEQ distribution patterns of the entire indoor space.The proposed method was applied to the analysis of indoor thermal environment in Beijing Daxing international airport terminal.As a result,four typical temperature spatial distribution patterns of the terminal were extracted from a four-month monitoring,which had been validated for their good representativeness.These typical patterns revealed typical environmental issues in the terminal,such as long-term localized overheating and temperature increases due to a sudden influx of people.The extracted typical IEQ spatial distribution patterns could assist building operators in effectively assessing the uneven distribution of IEQ space under current environmental conditions,facilitating targeted environmental improvements,optimization of thermal comfort levels,and application of energy-saving measures.

Evaluation of airborne transmission risk in university towns based on IEQ surveys

This study aims to evaluate airborne transmission risk in university towns during the COVID-19 pandemic based on surveys of indoor environmental quality(IEQ).Both on-site measurements and questionnaire surveys were carried out in public buildings in university towns in Changsha,China.Air temperature,relative humidity,and CO 2 concentration in one library,ten classrooms,eight canteens,seven restaurants,and sixteen malls were mea-sured.2220 valid questionnaires concerning occupants’sensation on thermal environment,air movement,and indoor air quality were collected.A 3-level evaluation method of airborne transmission risk that is dependent on building type and indoor CO 2 concentration was developed.Excessive CO 2 concentration is found in library(1045 ppm),classrooms(1151 ppm),restaurants(1242 ppm),and malls(1057 ppm).The percentage time of“high risk”accounts for 18-100%in these buildings.The results reveal a serious problem:numerous public buildings in China and probably other resource limited countries are not basically prepared and equipped to cope with airborne transmission.This fact should be taken into account when developing guidelines and formu-lating mitigation measures.Real-time monitoring and displaying IEQ and thus the transmission risk level should be an important way to be widely implemented in public buildings.