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Proper indoor air quality and thermal comfort are part of the healthy indoor environment. The tests performed in the public utility, intelligent building „Energies" of Kielce University of Technology (Poland) with a group of students are the focus of the paper. The anonymous questionnaire survey was used to determine their thermal sensations, preferences and acceptability before the lecture and after it. In the meantime CO2 level, air and globe temperatures, relative humidity and air velocity were measured with the Testo 400 microclimate meter. The comparison of the changing air parameters throughout the time of 1.2h with the questionnaire survey provides information on the possibility of providing high thermal comfort and indoor air quality in the intelligent buildings, which are still quite rare in Central Europe. Consequently, obtaining experimental data there is valuable and important. It turned out that the building did not provide good quality parameters during the study, because the people felt too warm or hot in the room and wanted to change the temperature to a much cooler environment. What is more, the assessment of air quality according to the students at the beginning of classes at relatively low CO2 contents turns out to be an interesting phenomenon, where 36% of students subjectively assessed it in their questionnaires as being unacceptable. [ABSTRACT FROM AUTHOR]

In the development of construction industry, it is necessary to maintain the quality of indoor air at a higher lev-el, preventing a decrease in the energy efficiency of heat supply for construction projects. Indoor air quality is character-ized by the composition of the building's indoor air environment. The creation of specified conditions is possible with a set of technical means: built-in air source heat pumps with forced ventilation and modern devices for analyzing air purity. The use of additional funds to improve air quality will increase the cost of developing design work. Taking these re-quirements into account when designing the production of works will lead to a rise in cost by 13%, however, the rational-ization of the planning scheme of the design process for low-rise buildings will allow this solution to remain competitive. Improving the indoor climate of the premises will have a positive effect on the well-being and working capacity of the people in it, therefore, a slight increase in the cost of developing design work can be considered justified. [ABSTRACT FROM AUTHOR]

Being comfortable and healthy in one's home is of the utmost importance and a contributing factor to the quality of their life, and it is greatly affected by the air quality of the residence. Therefore, the subject of this paper centres around the indoor air quality (IAQ) of a standard household in central Athens and how these components influence human health. The air quality assessment is conducted using particulate matter (PM) on-site continuous measurements taken from low-cost sensors (PurpleAir) installed both inside and outside the house. Focusing especially on PM2.5 data from September 2021 to September 2022, the Air Quality Index (AQI) and the number of exceedances are evaluated in detail, investigating the association between indoor and outdoor environments. [ABSTRACT FROM AUTHOR]

Indoor air quality (radon, pollution, thermal fatigue, ventilation) is crucial for health and performance, especially for children. It is necessary to increase public awareness about the significance of air quality, particularly radon. Environmental school networks can enhance public awareness and provide research opportunities for scientists. SINDAIR, a school network based on SIMA-AEP, provides a flexible platform for larger scale educational and research projects. SINDAIR is in its pilot phase, involving various schools around Greece. With the assistance of UniWA, SINDAIR has started a pilot radon measuring campaign. Preliminary results show increased radon concentrations in certain school rooms, higher than expected, justifying further radon risk and air quality assessment, management, and perception programs. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) provides a platform that allows devices to connect, discover and remotely control through the internet. This work aims to develop an Internet of Things-based system for an oil company's laboratory. It is intended to monitor its environmental conditions and parameters through air quality sensors, thus providing intelligent monitoring and greater certainty of working conditions. The system development utilizes ESP8266, Arduino UNO processor, solid-state relay, and sensors. The proposed work monitors the air quality, humidity, and temperature of the laboratory environment. It included an active air exhaust control system. A database has been created with the purpose of data analysis and access to status history. As a result of this system implementation, it is expected to improve laboratory management and occupational health and hygiene. [ABSTRACT FROM AUTHOR]

Air quality is the overall description of air pollution levels in a defined area that may affect the environment and public health. Over the years, increasing levels of air pollutants from natural and human-related sources lead to poor air quality. In urban areas where there are higher concentrations of people and air pollutants, poorer air quality would mean posing more detrimental health risks for its residents. Most exposed would be transport-workers such as traffic enforcers, drivers and daily commuters. Previous studies have proved that air pollutants coming from different components of the train cabin and ventilation system are significant sources of harmful air contaminants that could cause health risks and safety risks to passengers. Health effects of air pollution range from acute symptoms such as coughing and respiratory infections, to the development of chronic diseases and even mortality. This paper summarizes significant findings on the air quality inside the MRT 3 train cabins, including air contaminants and its effect on the health risk of passengers. The air contaminants assessed include carbon dioxide (CO2) and atmospheric particulate matter (PM2.5 and PM10). Also, a survey was conducted to determine the common illnesses experienced by the passengers and their causes. The results of the study revealed that concentration levels of CO2 have a strong positive correlation (r=0.828) to the volume of passengers inside the train cabin while the presence of particulate matter such as PM2.5 and PM10 has weak negative correlation (-.0.055 and -0.210) to the volume of passengers. However, the concentration of air pollutants must still be reduced since some passengers reported common illnesses such as headaches, dizziness, sickness, and breathing difficulties when riding MRT trains. Hence, the study recommends some interventions to maintain the good indoor air quality of the train cabins like installing small-scale air capture technology to lessen the CO2 concentration and installation of the air vent to lessen the atmospheric particulate matter inside the train cabins. [ABSTRACT FROM AUTHOR]

Indoor air quality is given lot of importance in modern societies and healthy environment. We spend most of time at indoor homes, workplace, offices, schools, hospitals, factories or even at the shopping malls e.t.c. The buildings may have good or bad indoor air quality (IAQ). Bad indoor air quality leads adverse impacts. If the Indoor air quality is not so good and tends to get poor then it affects the health, and the apparent effects get severe ultimately causing death. This study focuses on the assessment indoor air CO2 in classrooms of the educational institutes. To conduct the research work, many important studies from literature are surveyed and the standard followed internationally for the normal and abnormal levels of indoor air CO2 are kept as reference to rate the measured values. For the purpose of analysis, one government school, two private schools and two private centers are selected. During various visits to the institutions the required physical data regarding dimensions and conditions of classrooms are collected, which consists of number of doors, windows with dimensions and location, ventilation mode and number of fans etc. For noting these results, a data sheet is used. A questionnaire is also used to know the perceptions of teachers of these institutes about the impact of IAQ on the performance of students, teachers and several factors are analyzed in SPSS software. The indoor air CO2 is found to be in fair, good and excellent ranges in most of the institutes. However, in some classrooms, the CO2 concentrations is in higher ranges indicating the possibility of contaminated air, and this demanding more ways of ventilation. [ABSTRACT FROM AUTHOR]

In this work, we have used an IoT based approach along with required mathematical formulae to ascertain the quality of air in different indoor environments. By using the concept of an embedded technology, various sensors are connected to collect the data in different environments. The cloud technology is used for storing the sensed data. This collected data is stored in the information cloud and then inquired for the analysis of any environmental condition. This model is used to record and analyze such data in ThingSpeak. ThingSpeak is an analytic data platform for which IoT can be used as aggregation, visualization and analysis of live data steam in cloud. Moreover, Python codes are written for different mathematical formulae which are used in the ThingSpeak to check the environment condition. It has been observed that the graphical representation of environmental parameters in ThingSpeak gives the basic idea about the environment condition of that particular region. [ABSTRACT FROM AUTHOR]

The article proposes an air quality monitoring system in subway stations (possibly in trains) considering that air intake is made in many stations at ground level where the level of noxes (PM, CO2) is high. The proposed system uses sensors for air quality, presence of toxic gases, smoke and fire protection, monitors air quality and permanently provides this information to travelers either by accessing a site and / or locally via a graphical interface. Environmental monitoring information systems are systems of surveillance, forecasting, warning (alarm) and intervention that aim at systematically assessing the dynamics of the qualitative characteristics of the environmental factors in order to know the quality status and their environmental significance, the evolution and the implications social changes of the products, followed by system-determined measures. Based on measurements will notice that the level of emissions CO2, PM is quite high. Since there is not easily removed through ventilation when the air circulation does not provide enough fresh air stations / underground trains, especially in trains traveling environments underground. [ABSTRACT FROM AUTHOR]

Moisture accumulation and transport in the building barriers is an important feature that influences building performance, causing serious exploitation problems as increased energy use, mold and bacteria growth, decrease of indoor air parameters that may lead to sick building syndrome (SBS). One of the parameters that is used to describe moisture characteristic of the material is water absorption coefficient being the measure of capillary behavior of the material as a function of time and the surface area of the specimen. As usual it is determined using gravimetric methods according to EN 1925:1999 standard. In this article we demonstrate the possibility of determination of water absorption coefficient of autoclaved aerated concrete (AAC) using the Time Domain Reflectometry (TDR) method. TDR is an electric technique that had been adopted from soil science and can be successfully used for real-time monitoring of moisture transport in building materials and envelopes. Data achieved using TDR readouts show high correlation with standard method of moisture absorptivity coefficient determination. [ABSTRACT FROM AUTHOR]

The study aims at determining exposure-response relationships after short exposure to clean air and long exposure to air polluted by people. The impact of water vapor content in the indoor air on its acceptability (ACC) was assessed by the occupants after a short exposure to clean air and an hour-long exposure to increasingly polluted air. The study presents a critical analysis pertaining to the stimulation of olfactory sensations by the air enthalpy suggested in previous models and proposes a new model based on the Weber-Fechner law. Our assumption was that water vapor is the stimulus of olfactory sensations. The model was calibrated and verified in field conditions, in a mechanically ventilated and air conditioned auditorium. Measurements of the air temperature, relative humidity, velocity and CO2 content were carried out; the acceptability of air quality was assessed by 162 untrained students. The subjective assessments and the measurements of the environmental qualities allowed for determining the Weber coefficients and the threshold concentrations of water vapor, as well as for establishing the limitations of the model at short and long exposure to polluted indoor air. The results are in agreement with previous studies. The standard error equals 0.07 for immediate assessments and 0.17 for assessments after adaptation. Based on the model one can predict the ACC assessments of trained and untrained participants. [ABSTRACT FROM AUTHOR]

The microclimate conditions issue in school buildings has an indirect impact on the ability of concentration and attention of students and teachers in the educational process. Indoor air quality indicators consist of the internal temperature, air quality, lighting, dust levels, as well as chemical and biological factors. Research shows that inside of education and administration buildings there is quality of the environment perceived far below the acceptable level. This paper presents the results of screening measurements of particular factors in classroom obtained during learning process. There had been objectified factors such as temperature, humidity, light, and oxygen concentration at various classrooms occupancy. Questionnaires were aimed to evaluate the subjective factors and work environment and their possible impact on concentration and students' performance. The aim of this paper is to point out the importance of optimal values of parameters of the internal environment in schools. [ABSTRACT FROM AUTHOR]

The air ventilation rates defined in Standard STN EN 15 251:2007 present air change rate in which the objective benefit of proper selection of ventilation system and air distribution scheme is lost (erased) in relation to IAQ [1,2]. With help of sensory evaluation in research the total minimum ventilation rate was estimated. It was reason how to determine major boundary condition (air quantity = air ventilation rate) for minimizing of responsibility size of air quantity (quantitative component of ventilation) and maximize the impact of the choice of distribution scheme and the distribution element (qualitative component of ventilation) for transfer and distribution of pollutants in research. The total air ventilation rate for next experimental measurements was established as the intersection of three air ventilation rates according to research harmonogram. This air ventilation rate was necessary to supply to occupant to experimental classroom and also as input value to CFD simulations. Within the frame of air infiltration measurements (Description: older research, air infiltration quantification, 500 measurements for 6 categories of building types) that is presented in this paper, this value of air infiltration was determinated for an experimental classroom (Type of Buildings - Schools) at value level nINF=0,3[1/h] respectively qINF=16[litre/s]. It is average air infiltration value for Schools Buildings [3,4]. It was necessary to ensured increased air ventilation rate nMECH=1,0[1/h] respectively qMECH=53,3[litre/s] by mechanical ventilation system. These values were used and reflected in the experimental measurements and CFD simulations. [ABSTRACT FROM AUTHOR]

Our current research has been based on heat energy consumption analysis in the year 2008 and indoor environment - indoor air quality (IAQ) data analysis in day-care centre buildings in the year 2011. We have been analysed more than 420 public buildings heat energy consumption in the Riga city. All public buildings divided into 12 groups depending on these using. Our attention was focused on heat consumption in unrenovated, partially renovated and newly erected day-care centre buildings. Data of heat consumption in this group of public buildings we has analysed and modelled trend line under the Latvian Energy Development Guidelines for the years 2007-2016 and by the year 2020. It can be a main direction for Latvian civil engineering for current public building group. Obtained data indicated another, incorrect tendency in Latvian building sector. In the year 2011 we will be continued our research and obtained data of IAQ in six different conditions day-care centre buildings. IAQ measurements in three day care-centre buildings we would like to present in this article. [ABSTRACT FROM AUTHOR]

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 the indoor air quality and thermal comfort within six daycare centers (old, renovated and new-built) in moderate climate zone of Latvia. The measurements of carbon dioxide, air temperature and relative humidity were carried out, and the data regarding daycare center characteristics and maintenance activities were collected via combination of field visits, record analysis and interviews. It was found that the carbon dioxide concentrations exceeded 1000 ppm in 75% of the daycare centers studied, with the highest (1356 ppm) measured in a renovated facility with the natural ventilation system. Thus, installation of a 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°C and the average relative humidity was 40 ± 5%, creating comfortable thermal environment for children. [ABSTRACT FROM AUTHOR]

We present an ongoing project which aims at monitoring IAQ in multi-apartment buildings (MABs) before and after renovation. We collected measures of indoor air microclimate parameters in 6 apartments of 3 MABs of standard construction buildings (type 464) in Riga, during the heating season of 2010/2011. In 3 apartments of one renovated building and in 3 apartments of two unrenovated buildings (on the first, middle and top floor), sensors of air temperature, relative humidity, CO2 concentration level, and air flow velocity are located to find the average value of IAQ parameters, and to make calculations of indoor air exchange in each apartment. At the same time, the outdoor air temperature and relative humidity are measured. The measurements are made every minute, and the paper presents the data for duration of several months. In general, the results show that the ventilation system must be updated in all apartments. The thermal energy for heating is reduced by about 50% in renovated MAB. The heat energy consumption in different apartments of the renovated building and temperature measures in all the project apartments demonstrate the necessity to change the heat consumption according to individual financial possibilities and comfort demands. [ABSTRACT FROM AUTHOR]

Air conditioning in buildings is vital for people who spend much of the day indoors. The climate control industry views indoor air quality as a measure of temperature, humidity, and amount of volatile organic compounds. This paper introduces the concept of a Wi-Fi based measurement system that is tiny and low cost and works on battery power. Sensors for measurement of temperature, humidity, absolute pressure and air quality are mounted on the board. The node is able to read sensors and send data to the network by using an IP-based application protocol. [ABSTRACT FROM AUTHOR]

Prior to this work, predicted the optimal values of temperature humidity regime in cowsheds, which is necessary in designing and operating the ventilation systems. In addition, investigate the operation of ventilation systems in two cowsheds by observing the temperature differences between indoor and outdoor air, indoor air relative humidity, CO2 concentration. Having performed analytical research has been drawn an equation, which relates the temperature differences between indoor and outdoor air with the indoor air relative humidity, outdoor climate conditions and thermal factors of cowshed. Experimental research were carried out in two production cowshed with different thermal factors (one cowshed uninsulated, another with insulated roof - partly insulated) and different operation of ventilation systems. Both cowsheds dimensions of the ventilation system were designed sufficient size. The difference between the predicted and observed temperature humidity regime of uninsulated cowshed was non- essential, and average relative humidity of the indoor air was in line with the minimum possible. But for partly insulated cowshed observed difference between indoor and outdoor temperature humidity was too much, and in winter the indoor air humidity usually exceed the minimum possible and sometime reached 100 %. That's shows that ventilation system management was poor. [ABSTRACT FROM AUTHOR]