Indoor Air Quality

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Environmental Sciences".

Deadline for manuscript submissions: closed (31 August 2019) | Viewed by 68579

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Special Issue Editor

Atmospheric Chemistry & Innovative Technologies Laboratory, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Centre for Scientific Research “Demokritos”, 15310 Agia Paraskevi, Greece
Interests: indoor air quality; air pollution; source apportionment; particulate matter physics and chemistry; ventilation; exposure
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Special Issue Information

Dear Colleagues,

It is a fact that people in developed countries spend almost 90% of their time indoors, where they experience their greatest exposures. However, regulation for air pollution focuses on outdoor air, as indoor environment is less well-characterized and recognized as a potential location for exposure to air pollution.

What makes indoor air intrinsically more interesting than outdoor air from a scientific point of view? Undoubtedly, some sources are uniquely building-related (e.g., cleaning agents, emissions from building materials and personal care products), while some contaminant dynamics operate only in buildings (e.g., the distribution of particles and gases by mechanical ventilation systems and photochemical reactions, and the infiltration of soil gases). Besides, air pollutant concentrations are often higher indoors than outdoors, particularly following activities such as cleaning and cooking (with a greater source strength indoors than outdoor on a per area basis), while it has already been proven that many indoor air pollutants are harmful to human health.

Another issue is ventilation. While indoor microenvironments are a microcosm of most urban settings, the effective air exchange and renewal in buildings is much lower than in the free atmosphere, even in urban areas. This concern is amplified by the fact that energy efficiency measures, driven by climate change awareness, have made modern buildings more airtight, further degrading the quality of indoor air. Therefore, a person is significantly more likely to inhale a harmful chemical molecule if it is emitted indoors rather than outdoors.

Monitoring of indoor air pollutants in a spatio-temporal basis is challenging. A key element is the access to local (i.e., indoor residential, workplace, or public building) exposure measurements. Unfortunately, the high cost and complexity of most current air pollutant monitors results in a lack of detailed spatial and temporal resolution. As a result, individuals of vulnerable groups (children, pregnant, elderly, and sick people) have little insight into their personal exposure levels. This becomes significant in cases of hyper-local variations and short-term pollution events such as instant indoor activity (e.g., cooking, smoking, and dust resuspension). Advances in sensor miniaturization have encouraged the development of small, inexpensive devices capable of estimating pollutant concentrations. This new class of sensors presents new possibilities for indoor exposure monitoring.

On the other hand, indoor air chemistry models typically account for air exchange with outdoors through ventilation, deposition on indoor surfaces, and photochemical reactions. Surface chemistry on furnishings, building materials, and human bodies is increasingly recognized as being of crucial importance.

Therefore, this Special Issue invites research in the areas of the triptych: indoor air pollution monitoring, indoor air modeling, and exposure to indoor air pollution.  Topics of interest for the Special Issue include, but are not limited to, the following:

  • Low-cost sensors for indoor air monitoring
  • Indoor particulate matter and volatile organic compounds
  • Ozone-terpene chemistry
  • Biological agents indoors
  • Source apportionment
  • Exposure assessment
  • Health effects of indoor air pollutants
  • Occupant perception
  • Climate change impacts on indoor air quality

Dr. Dikaia E. Saraga
Guest Editor

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Keywords

  • Indoor air monitoring
  • Indoor modelling
  • Exposure assessment
  • Low-cost sensors

Published Papers (17 papers)

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Editorial

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4 pages, 202 KiB  
Editorial
Special Issue on Indoor Air Quality
by Dikaia E. Saraga
Appl. Sci. 2020, 10(4), 1501; https://doi.org/10.3390/app10041501 - 22 Feb 2020
Cited by 2 | Viewed by 1703
Abstract
It is a fact that people in developed countries spend almost 90% of their time indoors, where they experience their greatest exposures [...] Full article
(This article belongs to the Special Issue Indoor Air Quality)

Research

Jump to: Editorial

13 pages, 2520 KiB  
Article
A Promising Technological Approach to Improve Indoor Air Quality
by Thomas Maggos, Vassiliοs Binas, Vasileios Siaperas, Antypas Terzopoulos, Panagiotis Panagopoulos and George Kiriakidis
Appl. Sci. 2019, 9(22), 4837; https://doi.org/10.3390/app9224837 - 12 Nov 2019
Cited by 12 | Viewed by 3503
Abstract
Indoor Air quality (IAQ) in private or public environments is progressively recognized as a critical issue for human health. For that purpose the poor IAQ needs to be mitigated and immediate drastic measures must be taken. In environmental science and especially in advanced [...] Read more.
Indoor Air quality (IAQ) in private or public environments is progressively recognized as a critical issue for human health. For that purpose the poor IAQ needs to be mitigated and immediate drastic measures must be taken. In environmental science and especially in advanced oxidation processes and technologies (AOPs-AOTs), photocatalysis has gained considerable interest among scientists as a tool for IAQ improvement. In the current study an innovative paint material was developed which exhibits intense photocatalytic activity under direct and diffused visible light for the degradation of air pollutants, suitable for indoor use. A laboratory and a real scale study were performed using the above innovative photo-paint. The lab test was performed in a special design photo-reactor while the real scale in a military’s medical building. Nitrogen Oxide (NO) and Toluene concentration was monitored between “reference” rooms (without photo paint) and “green” rooms (with photo-paint) in order to estimate the photocatalytic efficiency of the photo-paint to degrade the above pollutants. Results of the study showed a decrease up to 60% and 16% for NO and toluene respectively under lab scale tests while an improvement of air quality up to 19% and 5% under real world conditions was achieved. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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23 pages, 858 KiB  
Article
An Accident Model with Considering Physical Processes for Indoor Environment Safety
by Zhengguo Yang, Yuto Lim and Yasuo Tan
Appl. Sci. 2019, 9(22), 4732; https://doi.org/10.3390/app9224732 - 06 Nov 2019
Cited by 5 | Viewed by 2878
Abstract
Accident models provide a conceptual representation of accident causation. They have been applied to environments that have been exposed to poisonous or dangerous substances that are hazardous in nature. The home environment refers to the indoor space with respect to the physical processes [...] Read more.
Accident models provide a conceptual representation of accident causation. They have been applied to environments that have been exposed to poisonous or dangerous substances that are hazardous in nature. The home environment refers to the indoor space with respect to the physical processes the of indoor climate, e.g., temperature change, which are not hazardous in general. However, it can be hazardous when the physical process is in some states, e.g., a state of temperature that can cause heat stroke. If directly applying accident models in such a case, the physical processes are missing. To overcome this problem, this paper proposes an accident model by extending the state-of-the-art accident model, i.e., Systems-Theoretic Accident Model and Process (STAMP) with considering physical processes. Then, to identify causes of abnormal system behaviors that result in physical process anomalies, a hazard analysis technique called System-Theoretic Process Analysis (STPA) is tailored and applied to a smart home system for indoor temperature adjustment. The analytical results are documented by a proposed landscape genealogical layout documentation. A comparison with results by applying the original STPA was made, which demonstrates the effectiveness of the tailored STPA to apply in identifying causes in our case. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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11 pages, 534 KiB  
Article
Cooking/Window Opening and Associated Increases of Indoor PM2.5 and NO2 Concentrations of Children’s Houses in Kaohsiung, Taiwan
by Yu-Chuan Yen, Chun-Yuh Yang, Kristina Dawn Mena, Yu-Ting Cheng and Pei-Shih Chen
Appl. Sci. 2019, 9(20), 4306; https://doi.org/10.3390/app9204306 - 14 Oct 2019
Cited by 7 | Viewed by 2378
Abstract
High concentrations of air pollutants and increased morbidity and mortality rates are found in industrial areas, especially for the susceptible group, children; however, most studies use atmospheric dispersion modeling to estimate household air pollutants. Therefore, the aim of this study was to assess [...] Read more.
High concentrations of air pollutants and increased morbidity and mortality rates are found in industrial areas, especially for the susceptible group, children; however, most studies use atmospheric dispersion modeling to estimate household air pollutants. Therefore, the aim of this study was to assess the indoor air quality, e.g., CO, CO2, NO2, SO2, O3, particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5), and their influence factors in children’s homes in an industrial city. Children in the “general school”, “traffic school”, and “industrial school” were randomly and proportionally selected. Air pollutants were sampled for 24 h in the living rooms and on the balcony of their houses and questionnaires of time–microenvironment–activity-diary were recorded. The indoor CO concentration of the traffic area was significantly higher than that of the industrial area and the general area. In regard to the effects of window opening, household NO2 and PM2.5 concentrations during window opening periods were significantly higher than of the reference periods. For the influence of cooking, indoor CO2, NO2, and PM2.5 levels during the cooking periods were significantly higher than that of the reference periods. The indoor air quality of children in industrial cities were affected by residential areas and household activities. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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35 pages, 3156 KiB  
Article
Combined Model for IAQ Assessment: Part 1—Morphology of the Model and Selection of Substantial Air Quality Impact Sub-Models
by Michał Piasecki and Krystyna Barbara Kostyrko
Appl. Sci. 2019, 9(18), 3918; https://doi.org/10.3390/app9183918 - 18 Sep 2019
Cited by 18 | Viewed by 3593
Abstract
Indoor air quality (IAQ) is one of the most important elements affecting a building user’s comfort and satisfaction. Currently, many methods of assessing the quality of indoor air have been described in the literature. In the authors’ opinion, the methods presented have not [...] Read more.
Indoor air quality (IAQ) is one of the most important elements affecting a building user’s comfort and satisfaction. Currently, many methods of assessing the quality of indoor air have been described in the literature. In the authors’ opinion, the methods presented have not been collected, systematized, and organized into one multi-component model. The application purpose of the assessment is extremely important when choosing IAQ model. This article provides the state-of-the-art overview on IAQ methodology and attempts to systematize approach. Sub-models of the processes that impact indoor air quality, which can be distinguished as components of the IAQ model, are selected and presented based on sensory satisfaction functions. Subcomponents of three potential IAQ models were classified according to their application potential: IAQ quality index, IAQ comfort index, and an overall health and comfort index. The authors provide a method for using the combined IAQ index to determine the indoor environmental quality index, IEQ. In addition, the article presents a method for adjusting the weights of particular subcomponents and a practical case study which provides IAQ and IEQ model implementation for a large office building assessment (with a BREEAM rating of excellent). Full article
(This article belongs to the Special Issue Indoor Air Quality)
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16 pages, 2051 KiB  
Article
Residents’ Perceptions of and Response Behaviors to Particulate Matter—A Case Study in Seoul, Korea
by Myung Eun Cho and Mi Jeong Kim
Appl. Sci. 2019, 9(18), 3660; https://doi.org/10.3390/app9183660 - 04 Sep 2019
Cited by 5 | Viewed by 1973
Abstract
This study is interested in understanding the particulate matter perceptions and response behaviors of residents. The purpose of this study was to identify indoor air quality along with the response behaviors of residents in Seoul, to ascertain whether there is a difference in [...] Read more.
This study is interested in understanding the particulate matter perceptions and response behaviors of residents. The purpose of this study was to identify indoor air quality along with the response behaviors of residents in Seoul, to ascertain whether there is a difference in behaviors when particulate matter is present, according to the characteristics of residents and to grasp the nature of this difference. A questionnaire survey of 171 respondents was conducted. The questionnaire measured the indoor air quality perceived by residents, the health symptoms caused by particulate matter, residents’ response behaviors to particulate matter and the psychological attributes affecting those response behaviors. Residents of Seoul were divided into college students in their twenties, male workers in their thirties and forties and female housewives in their thirties and forties. The data were calibrated by SPSS 23 using a one-way analysis of variance (ANOVA) and multiple regression analyses. The results show that most people found particulate matter to be an important problem but were unable to do sufficient mitigation action to prevent its presence. Residents showed greater psychological stress resulting in difficulty going out than physical symptoms. The most influential factor on response behaviors was psychological attributes. Participants were aware of the risks of particulate matter but believed it to be generated by external factors; thus, they felt powerless to do anything about it, which proved to be an obstacle to response behaviors. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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12 pages, 1990 KiB  
Article
Keeping Doors Closed as One Reason for Fatigue in Teenagers—A Case Study
by Anna Mainka and Elwira Zajusz-Zubek
Appl. Sci. 2019, 9(17), 3533; https://doi.org/10.3390/app9173533 - 28 Aug 2019
Cited by 11 | Viewed by 2769
Abstract
(1) Background: Healthy teenagers are often sleepy. This can be explained by their physiology and behavioral changes; however, the influence of CO2 concentration above 1000 ppm should not be neglected with respect to sleep dissatisfaction. (2) Methods: CO2 concentrations were measured [...] Read more.
(1) Background: Healthy teenagers are often sleepy. This can be explained by their physiology and behavioral changes; however, the influence of CO2 concentration above 1000 ppm should not be neglected with respect to sleep dissatisfaction. (2) Methods: CO2 concentrations were measured in two similar bedrooms occupied by girls aged 9 and 13 years old. The scheme of measurements included random opening and closing of the bedroom doors for the night. Additionally, the girls evaluated their sleep satisfaction in a post-sleep questionnaire. (3) Results: During the night, the CO2 concentration varied from 402 to 3320 ppm in the teenager’s bedroom and from 458 to 2176 ppm in the child’s bedroom. When the bedroom doors were open, inadequate indoor air quality (IEQIII and IEQIV categories) was observed in both the teenager’s and child’s bedroom during 11% and 25% of the night, respectively; however, closing the doors increased the contribution of moderate (IEQIII) and low (IEQIV) categories of air to 79% and 86%, respectively. The girls were dissatisfied only when the bedroom door was closed. The satisfied category of sleep was selected only by the younger girl. (4) Conclusions: Opening the bedroom door during the night can decrease the CO2 concentration 55–64% without reducing thermal comfort. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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13 pages, 3699 KiB  
Article
Real-Time Monitoring of Indoor Air Quality with Internet of Things-Based E-Nose
by Mehmet Taştan and Hayrettin Gökozan
Appl. Sci. 2019, 9(16), 3435; https://doi.org/10.3390/app9163435 - 20 Aug 2019
Cited by 77 | Viewed by 15211
Abstract
Today, air pollution is the biggest environmental health problem in the world. Air pollution leads to adverse effects on human health, climate and ecosystems. Air is contaminated by toxic gases released by industry, vehicle emissions and the increased concentration of harmful gases and [...] Read more.
Today, air pollution is the biggest environmental health problem in the world. Air pollution leads to adverse effects on human health, climate and ecosystems. Air is contaminated by toxic gases released by industry, vehicle emissions and the increased concentration of harmful gases and particulate matter in the atmosphere. Air pollution can cause many serious health problems such as respiratory, cardiovascular and skin diseases in humans. Nowadays, where air pollution has become the largest environmental health risk, the interest in monitoring air quality is increasing. Recently, mobile technologies, especially the Internet of Things, data and machine learning technologies have a positive impact on the way we manage our health. With the production of IoT-based portable air quality measuring devices and their widespread use, people can monitor the air quality in their living areas instantly. In this study, e-nose, a real-time mobile air quality monitoring system with various air parameters such as CO2, CO, PM10, NO2 temperature and humidity, is proposed. The proposed e-nose is produced with an open source, low cost, easy installation and do-it-yourself approach. The air quality data measured by the GP2Y1010AU, MH-Z14, MICS-4514 and DHT22 sensor array can be monitored via the 32-bit ESP32 Wi-Fi controller and the mobile interface developed by the Blynk IoT platform, and the received data are recorded in a cloud server. Following evaluation of results obtained from the indoor measurements, it was shown that a decrease of indoor air quality was influenced by the number of people in the house and natural emissions due to activities such as sleeping, cleaning and cooking. However, it is observed that even daily manual natural ventilation has a significant improving effect on air quality. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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25 pages, 2590 KiB  
Article
Personal Control of the Indoor Environment in Offices: Relations with Building Characteristics, Influence on Occupant Perception and Reported Symptoms Related to the Building—The Officair Project
by Ioannis Sakellaris, Dikaia Saraga, Corinne Mandin, Yvonne de Kluizenaar, Serena Fossati, Andrea Spinazzè, Andrea Cattaneo, Tamas Szigeti, Victor Mihucz, Eduardo de Oliveira Fernandes, Krystallia Kalimeri, Paolo Carrer and John Bartzis
Appl. Sci. 2019, 9(16), 3227; https://doi.org/10.3390/app9163227 - 07 Aug 2019
Cited by 23 | Viewed by 3584
Abstract
Personal control over various indoor environment parameters, especially in the last decades, appear to have a significant role on occupants’ comfort, health and productivity. To reveal this complex relationship, 7441 occupants of 167 recently built or retrofitted office buildings in eight European countries [...] Read more.
Personal control over various indoor environment parameters, especially in the last decades, appear to have a significant role on occupants’ comfort, health and productivity. To reveal this complex relationship, 7441 occupants of 167 recently built or retrofitted office buildings in eight European countries participated in an online survey about personal/health/work data as well as physical/psycho-social information. The relationship between the types of control available over indoor environments and the perceived personal control of the occupants was examined, as well as the combined effect of the control parameters on the perceived comfort using multilevel statistical models. The results indicated that most of the occupants have no or low control on noise. Half of the occupants declared no or low control on ventilation and temperature conditions. Almost one-third of them remarked that they do not have satisfactory levels of control for lighting and shading from sun conditions. The presence of operable windows was shown to influence occupants’ control perception over temperature, ventilation, light and noise. General building characteristics, such as floor number and floor area, office type, etc., helped occupants associate freedom positively with control perception. Combined controlling parameters seem to have a strong relation with overall comfort, as well as with perception regarding amount of privacy, office layout and decoration satisfaction. The results also indicated that occupants with more personal control may have less building-related symptoms. Noise control parameter had the highest impact on the occupants’ overall comfort. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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11 pages, 441 KiB  
Article
How Working Tasks Influence Biocontamination in an Animal Facility
by Anna M. Marcelloni, Alessandra Chiominto, Simona Di Renzi, Paola Melis, Annarita Wirz, Maria C. Riviello, Stefania Massari, Renata Sisto, Maria C. D’Ovidio and Emilia Paba
Appl. Sci. 2019, 9(11), 2216; https://doi.org/10.3390/app9112216 - 29 May 2019
Cited by 3 | Viewed by 2235
Abstract
The exposure to biocontaminants in animal facilities represents a risk for developing infectious, allergic and toxic diseases. The aim of this study was to determine what factors could be associated with a high level of exposure to biological agents through the measure and [...] Read more.
The exposure to biocontaminants in animal facilities represents a risk for developing infectious, allergic and toxic diseases. The aim of this study was to determine what factors could be associated with a high level of exposure to biological agents through the measure and characterization of airborne fungi, bacteria, endotoxin, (1,3)-β-d-glucan and animal allergens. Airborne microorganisms were collected with an air sampler and identified by microscopic and biochemical methods. Endotoxin, (1,3)-β-d-glucan, Mus m 1, Rat n 1, Can f 1, Fel d 1, Equ c 4 allergens were detected on inhalable dust samples by Kinetic LAL, Glucatell, and ELISA assays, respectively. Our data evidenced that changing cages is a determinant factor in increasing the concentration of the airborne biocontaminants; the preparation of bedding and distribution of feed, performed in the storage area, is another critical working task in terms of exposure to endotoxins (210.7 EU/m3) and (1,3)-β-d-glucans (4.3 ng/m3). The highest concentration of Mus m 1 allergen (61.5 ng/m3) was observed in the dirty washing area. The detection of expositive peaks at risk of sensitization (>2 μg/g) by Fel d 1 in animal rooms shows passive transport by operators themselves, highlighting their role as vehicle between occupational and living environments. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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14 pages, 760 KiB  
Article
Evaluation of Performance of Inexpensive Laser Based PM2.5 Sensor Monitors for Typical Indoor and Outdoor Hotspots of South Korea
by Sungroul Kim, Sujung Park and Jeongeun Lee
Appl. Sci. 2019, 9(9), 1947; https://doi.org/10.3390/app9091947 - 12 May 2019
Cited by 34 | Viewed by 4371
Abstract
Inexpensive (<$300) real-time particulate matter monitors (IRMs), using laser as a light source, have been introduced for use with a Wi-Fi function enabling networking with a smartphone. However, the information of measurement error of these inexpensive but convenient IRMs are still limited. Using [...] Read more.
Inexpensive (<$300) real-time particulate matter monitors (IRMs), using laser as a light source, have been introduced for use with a Wi-Fi function enabling networking with a smartphone. However, the information of measurement error of these inexpensive but convenient IRMs are still limited. Using ESCORTAIR (ESCORT, Seoul, Korea) and PurpleAir (PA) (PurpleAir U.S.A.), we evaluated the performance of these two devices compared with the U.S. Environmental Protection Agency (EPA) Federal Equivalent Monitoring (FEM) devices, that is, GRIMM180 (GRIMM Aerosol, Germany) for the indoor measurement of pork panfrying or secondhand tobacco smoking (SHS) and Beta-ray attenuation monitor (BAM) (MetOne, Grants Pass, OR) for outdoor measurement at the national particulate matter (PM2.5) monitoring site near an urban traffic hotspot in Daejeon, South Korea, respectively. The PM2.5 concentrations measured by ESCORTAIR and PA were strongly correlated to FEM (r = 0.97 and 0.97 from indoor pan frying; 0.92 and 0.86 from indoor SHS; 0.85 and 0.88 from outdoor urban traffic hotspot). The two IRMs showed that PM2.5 mass concentrations were increased with increased outdoor relative humidity (RH) levels. However, after applying correction factors for RH, the Median (Interquartile range) of difference compared to FEM was (14.5 (6.1~23.5) %) for PA and 16.3 (8.5–28.0) % for ESCORTAIR, supporting their usage in the home or near urban hotspots. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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14 pages, 1238 KiB  
Article
A Contactless Measuring Method of Skin Temperature based on the Skin Sensitivity Index and Deep Learning
by Xiaogang Cheng, Bin Yang, Kaige Tan, Erik Isaksson, Liren Li, Anders Hedman, Thomas Olofsson and Haibo Li
Appl. Sci. 2019, 9(7), 1375; https://doi.org/10.3390/app9071375 - 01 Apr 2019
Cited by 15 | Viewed by 3325
Abstract
In human-centered intelligent building, real-time measurements of human thermal comfort play critical roles and supply feedback control signals for building heating, ventilation, and air conditioning (HVAC) systems. Due to the challenges of intra- and inter-individual differences and skin subtleness variations, there has not [...] Read more.
In human-centered intelligent building, real-time measurements of human thermal comfort play critical roles and supply feedback control signals for building heating, ventilation, and air conditioning (HVAC) systems. Due to the challenges of intra- and inter-individual differences and skin subtleness variations, there has not been any satisfactory solution for thermal comfort measurements until now. In this paper, a contactless measuring method based on a skin sensitivity index and deep learning (NISDL) was proposed to measure real-time skin temperature. A new evaluating index, named the skin sensitivity index (SSI), was defined to overcome individual differences and skin subtleness variations. To illustrate the effectiveness of SSI proposed, a two multi-layers deep learning framework (NISDL method I and II) was designed and the DenseNet201 was used for extracting features from skin images. The partly personal saturation temperature (NIPST) algorithm was use for algorithm comparisons. Another deep learning algorithm without SSI (DL) was also generated for algorithm comparisons. Finally, a total of 1.44 million image data was used for algorithm validation. The results show that 55.62% and 52.25% error values (NISDL method I, II) are scattered at (0 °C, 0.25 °C), and the same error intervals distribution of NIPST is 35.39%. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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9 pages, 447 KiB  
Article
Application of Airborne Microorganism Indexes in Offices, Gyms, and Libraries
by Pietro Grisoli, Marco Albertoni and Marinella Rodolfi
Appl. Sci. 2019, 9(6), 1101; https://doi.org/10.3390/app9061101 - 15 Mar 2019
Cited by 16 | Viewed by 3695
Abstract
The determination of microbiological air quality in sporting and working environments requires the quantification of airborne microbial contamination. The number and types of microorganisms, detected in a specific site, offer a useful index for air quality valuation. An assessment of contamination levels was [...] Read more.
The determination of microbiological air quality in sporting and working environments requires the quantification of airborne microbial contamination. The number and types of microorganisms, detected in a specific site, offer a useful index for air quality valuation. An assessment of contamination levels was carried out using three evaluation indices for microbiological pollution: the global index of microbiological contamination per cubic meter (GIMC/m3), the index of mesophilic bacterial contamination (IMC), and the amplification index (AI). These indices have the advantage of considering several concomitant factors in the formation of a microbial aerosol. They may also detect the malfunction of an air treatment system due to the increase of microbes in aeraulic ducts, or inside a building compared to the outdoor environment. In addition, they highlight the low efficiency of a ventilation system due to the excessive number of people inside a building or to insufficient air renewal. This study quantified the levels of microorganisms present in the air in different places such as offices, gyms, and libraries. The air contamination was always higher in gyms that in the other places. All examined environments are in Northern Italy. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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15 pages, 4611 KiB  
Article
An Investigation of the Effects of Changes in the Indoor Ambient Temperature on Arousal Level, Thermal Comfort, and Physiological Indices
by Jongseong Gwak, Motoki Shino, Kazutaka Ueda and Minoru Kamata
Appl. Sci. 2019, 9(5), 899; https://doi.org/10.3390/app9050899 - 03 Mar 2019
Cited by 15 | Viewed by 3312
Abstract
Thermal factors not only affect the thermal comfort sensation of occupants, but also affect their arousal level, productivity, and health. Therefore, it is necessary to control thermal factors appropriately. In this study, we aim to design a thermal environment that improves both the [...] Read more.
Thermal factors not only affect the thermal comfort sensation of occupants, but also affect their arousal level, productivity, and health. Therefore, it is necessary to control thermal factors appropriately. In this study, we aim to design a thermal environment that improves both the arousal level and thermal comfort of the occupants. To this end, we investigated the relationships between the physiological indices, subjective evaluation values, and task performance under several conditions of changes in the indoor ambient temperature. In particular, we asked subjects to perform a mathematical task and subjective evaluation related to their thermal comfort sensation and drowsiness levels. Simultaneously, we measured their physiological parameters, such as skin temperature, respiration rate, electroencephalography, and electrocardiography, continuously. We investigated the relationship between the comfort sensation and drowsiness level of occupants, and the physiological indices. From the results, it was confirmed that changes in the indoor ambient temperature can improve both the thermal comfort and the arousal levels of occupants. Moreover, we proposed the evaluation indices of the thermal comfort and the drowsiness level of occupants using physiological indices. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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30 pages, 6333 KiB  
Article
Study of Passive Adjustment Performance of Tubular Space in Subway Station Building Complexes
by Junjie Li, Shuai Lu, Qingguo Wang, Shuo Tian and Yichun Jin
Appl. Sci. 2019, 9(5), 834; https://doi.org/10.3390/app9050834 - 26 Feb 2019
Cited by 10 | Viewed by 3485
Abstract
The stereo integration of subway transportation with urban functions has promoted the transformation of urban space via extensive two-dimensional plans to intensive three-dimensional development. As sustainable development aspect, it has posed new challenges for the design of architectural space to be better environmental [...] Read more.
The stereo integration of subway transportation with urban functions has promoted the transformation of urban space via extensive two-dimensional plans to intensive three-dimensional development. As sustainable development aspect, it has posed new challenges for the design of architectural space to be better environmental quality and low energy consumption. Therefore, subway station building complexes with high-performance designs should be a primary focus. Tubular space is a very common spatial form in subway station building complexes; it is an important space carrier for transmitting airflow and natural light. As such, it embodies the advantages of effectively utilizing natural resources, improving the indoor thermal and light environments, refining the air quality, and reducing energy consumption. This research took tubular space, which has a passive regulation function in subway station building complexes as its research object. It firstly established a scientific and logical method for verifying the value of tubular space by searching causal relationships among the parameterized building space information factors, occupancy satisfaction elements, physical environment comfort aspects, and climate conditions. Secondly, based on the actual field investigation, a database of physical environment performance data and users’ subjective satisfaction information was collected. Through the fieldwork results and analysis, the research thirdly concluded that the potential passive utilization of tubular space in subway station building complexes can be divided into two aspects: improvement in comfort level itself and utilization of climate between natural or artificial. Finally, three typical integrated design method for tubular spaces exhibiting high levels of performance and low amounts of energy consumption in subway station building complexes was put forward. This interdisciplinary research provides a design basis for subway station building complexes seeking to achieve high levels of performance and low amounts of energy consumption. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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17 pages, 4489 KiB  
Article
An Internet of Things-Based Environmental Quality Management System to Supervise the Indoor Laboratory Conditions
by Gonçalo Marques and Rui Pitarma
Appl. Sci. 2019, 9(3), 438; https://doi.org/10.3390/app9030438 - 28 Jan 2019
Cited by 30 | Viewed by 5113
Abstract
Indoor air quality (IAQ) is not only a determinant of occupational health but also influences all indoor human behaviours. In most university establishments, laboratories are also used as classrooms. On one hand, indoor environment quality (IEQ) conditions supervision in laboratories is relevant for [...] Read more.
Indoor air quality (IAQ) is not only a determinant of occupational health but also influences all indoor human behaviours. In most university establishments, laboratories are also used as classrooms. On one hand, indoor environment quality (IEQ) conditions supervision in laboratories is relevant for experimental activities. On the other hand, it is also crucial to provide a healthy and productive workplace for learning activities. The proliferation of cost-effective sensors and microcontrollers along with the Internet of Things (IoT) architectures enhancements, enables the development of automatic solutions to supervise the Laboratory Environmental Conditions (LEC). This paper aims to present a real-time IEQ-laboratory data collection system-based IoT architecture named iAQ Plus (iAQ+). The iAQ+ incorporates an integrated Web management system along with a smartphone application to provide a historical analysis of the LEC. The iAQ+ collects IAQ index, temperature, relative humidity and barometric pressure. The results obtained are promising, representing a meaningful contribution for IEQ supervision solutions based on IoT. iAQ+ supports push notifications to alert people in a timely way for enhanced living environments and occupational health, as well as a work mode feature, so the user can configure setpoints for laboratory mode and schoolroom mode. Using the iAQ+, it is possible to provide an integrated management of data information of the spatio-temporal variations of LEC parameters which are particularly significant not only for enhanced living environments but also for laboratory experiments. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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15 pages, 1343 KiB  
Article
Probability of Abnormal Indoor Air Exposure Categories Compared with Occupants’ Symptoms, Health Information, and Psychosocial Work Environment
by Katja Tähtinen, Sanna Lappalainen, Kirsi Karvala, Marjaana Lahtinen and Heidi Salonen
Appl. Sci. 2019, 9(1), 99; https://doi.org/10.3390/app9010099 - 28 Dec 2018
Cited by 11 | Viewed by 3604
Abstract
Indoor air problems are complicated and need to be approached from many perspectives. In this research, we studied the association of four-level categorisation of the probability of abnormal indoor air (IA) exposure with the work environment-related symptoms, group-level health information and psychosocial work [...] Read more.
Indoor air problems are complicated and need to be approached from many perspectives. In this research, we studied the association of four-level categorisation of the probability of abnormal indoor air (IA) exposure with the work environment-related symptoms, group-level health information and psychosocial work environment of employees. We also evaluated the multiprofessional IA group assessment of the current indoor air quality (IAQ) of the hospital premises. We found no statistical association between the four-level categorisation of the probability of abnormal IA exposure and the employees’ perceived symptoms, health information, and perceived psychosocial work environment. However, the results showed a statistical association between perceived symptoms and man-made vitreous fibre sources in ventilation. Furthermore, extensive impurity sources in the premises increased the employees’ contact with health services and their perceived symptoms. The employees perceived stress and symptoms in all categories of abnormal IA exposure, which may be related to IAQ or other factors affecting human experience. Prolonged process management may influence users’ experiences of IAQ. The results suggest that an extensive impurity source in premises does not always associate with the prevalence of perceived symptoms. We conclude that indoor air questionnaires alone cannot determine the urgency of the measures required. Full article
(This article belongs to the Special Issue Indoor Air Quality)
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