Radon is a naturally occurring, colourless and odourless radioactive gas, with a halflife of 3.8 days. Dangerous is not radon itself, but its progeny (daughter) products. The radon decay products irradiating of the lung. There is a strong correlation between radon exposure and lung cancer. The indoor radon concentrations in residential buildings are monitored. The study is performed in eight storied blocks of flats and also in family houses. The contributed deals with the radon concentration depending on a year season and floor level. Radon concentrations are varying with the characteristics of the building and its ventilation. Statistical analysis of the results shows that the probability that a weekly measurement represents the yearly radon concentration is significantly higher (twice) in winter and in summer than in summer and autumn. The maximum values of radon concentration is obtained in the first and second-floor rooms might be due to the contribution of radon emanation from the soil, entering into the living spaces from the ground.

Ambient comfort maintenance accompanied by excessive energy consumption is hugely criticized concerning the limited sustainability of the building sector in the long-term. In this sense, the energy reduction strategies based on the employment of passive air-control techniques are viewed as a prospective solution for improved energy performance. In order to contribute to this significant issue, this paper is aimed at the design and material characterization of novel plaster with an improved thermal and humidity control performance. For this purpose, a form-stable diatomite/dodecanol-based phase change material together with superabsorbent polymer are used as admixtures for the passive moderation of indoor air quality by newly designed modified plasters. The experimental assessment of the functional properties by means of mechanical strength, thermal conductivity, and hygric properties is performed. Considering the goal of the paper, particular attention is paid to the characterization of water vapor storage and moisture buffering according to the Nordtest method. Differential scanning calorimetry is employed for the description of phase change intervals as well as the specific enthalpy of phase change. The obtained results point to significant improvements in the hygroscopic performance and increased thermal energy storage that can be used for passive moderation of the indoor temperature and reduction of the relative humidity swings.

The current knowledge shows that the interior microclimate of residential buildings that were constructed between 1950 and 1990 using panel construction, not only in the Czech Republic but also in Europe, and were renovated in accordance with applicable legislation related to thermal comfort and energy is significantly affected by gaseous pollutants. At increased concentrations and exposure times, these pollutants negatively affect the interior microclimate and at the same time have a negative effect on the health of users. After the implementation of remediation measures, which are mainly focused on improving the thermal technical parameters of the building envelope, the concentration of CO₂ in the indoor environment increases. Carbon dioxide is one of the most important active factors and in terms of the quality of the interior microclimate, it is considered a reliable indicator of whether the interior microclimate can be considered a healthy and favorable environment. It is thus clear that the set and de facto systematized measures in the renovation of the housing stock from the second half of the 20th century has led to energy savings on the one hand, but on the other hand, this has contributed to the hygienic damage of housing units and an unhealthy interior microclimate. The paper aims to define the interaction of interdisciplinary contexts that have led to an increase in the indoor air quality (IAQ) of renovated residential panel buildings.

Indoor environment quality (IEQ) and its effect on well-being, productivity and performance are phenomena. Achieving suitable and comfortable indoor environment is a key factor in the creation and operation of the buildings in terms of basic principles of the sustainable development. The poor indoor environment is associated with the Sick Building Syndrome (SBS). The occurrence of pollutants in the indoor environment brings health problems to occupants as well as affects their productivity and performance. The main aim of the contribution is the study of indoor environment for educational purposes. The ordinary university classrooms located on the outskirts of the city České Budějovice (Czechia) are analysed. The classrooms are places, where the students reading, calculating, writing, and solving the assigned tasks. Achieving and satisfying the comfort in the indoor environment for education purposes is necessary for these student’s activities. For example, insufficient air exchange and the CO₂ concentration above of 1000 ppm, cause fatigue and decreased concentration. The assessment of physical-chemical parameters includes analysis of indoor air temperature [°C], relative humidity [%], Carbon Dioxide (CO₂) concentration [ppm], and illumination intensity [lx] in the university classrooms. The high-quality sensor for measuring air flow, temperature, humidity, pressure, heat radiation, CO₂ concentration and illumination intensity Testo 480 with globe probe, IAQ probe, light probe and comfort level probe is used for measurement. The work is supported by the grant Specific University Research SVV 201802 Address identification and analysis of the determinants of the Indoor Environment Quality (IEQ).

The contribution reports on a simulation study of indoor air quality in relation to different ventilation rates specified for 3 categories of the indoor environment according to EN 15 251. Indoor air quality and energy management are often at the opposite ends of the building management spectrum. The buildings are polluted by occupants of the building themselves. The indoor air quality can be expressed at the required level of ventilation or Carbon Dioxide (CO₂) concentration. Actually, the indoor air quality is influenced by emission from building surface materials and furnishing, occupants and their activities. VOCs play an important role in the indoor air quality evaluation process. VOC emissions adversely affect both occupant comfort and health. Most of the health hazards associated with VOC emissions occur during the first few weeks of building use. The Indoor Air Quality Emission Simulation Tool developed by National Research Council is used for simulating the VOCs emission impact of selected materials based on the amount of materials used and the ventilation rates in a model room, in this case study. IA-Quest predicts the emission of VOCs from building surface materials and furnishings, helping to select low-emission materials and effective ventilation strategies. The results showed the benefit of removing the increased amount of TVOC generated in time of the unoccupied period. The differences in TVOC concentrations were not obvious between two higher ventilation conditions (2.00 and 1.40 l/s.m²). More significant difference was estimated between categories A, B and category C (0.80 l/s.m²).

Building environmental audit and the assessment of indoor air quality (IAQ) in typical residential buildings is necessary process to ensure users' health and well-being. The paper deals with the concentrations on indoor dust particles (PM₁₀) in the context of hygrothermal microclimate in indoor environment. The indoor temperature, relative humidity and air movement are basic significant factors determining the PM₁₀ concentration [μg/m³]. The experimental measurements in this contribution represent the impact of indoor physical parameters on the concentration of particulate matter mass concentration. The occurrence of dust particles is typical for the almost two-thirds of interiors of the buildings. Other parameters indoor environment, such as air change rate, volume of the room, roughness and porosity of the building material surfaces, static electricity, light ions and others, were set constant and they are not taken into account in this study. The mass concentration of PM₁₀ is measured during summer season in apartment of residential prefabricated building. The values of global temperature [°C] and relative humidity of indoor air [%] are also monitored. The quantity of particulate mass matter is determined gravimetrically by weighing according to CSN EN 12 341 (2014). The obtained results show that the temperature difference of the internal environment does not have a significant effect on the concentration PM₁₀. Vice versa, the difference of relative humidity exhibits a difference of the concentration of dust particles. Higher levels of indoor particulates are observed for low values of relative humidity. The decreasing of relative air humidity about 10% caused 10µg/m³ of PM₁₀ concentration increasing. The hygienic limit value of PM₁₀ concentration is not exceeded at any point of experimental measurement.