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In Poland and other countries in Central Europe, residential buildings from the second half of the 20th century dominate, which have recently undergone deep thermomodernisation. Research on the retrofitting of residential buildings has focused mainly on energy efficiency, with only a few studies on indoor air quality. The aim of this study was to present a comparative analysis of the impact of five ventilation scenarios (three natural and two mechanical) on CO2 concentration and energy demand for heating and ventilation in residential spaces of a multi-family building located in Poland. The analyses were based on the results of building performance co-simulation using the EnergyPlus and CONTAM programs carried out under dynamic conditions with a 5 min time step for the entire heating season. The calculations took into account the instantaneous occupancy variability of twenty apartments. In the buildings equipped with new tight windows, the natural ventilation system provided extremely low air exchange (on average 0.1 h−1) and poor indoor air quality (average CO2 concentration at the level of 2500 ppm). Opening windows to ventilate the rooms generated a multiple increase (up to 8 times) in heating demand during these periods, but average CO2 concentration was on the level of 930 ppm. The use of mechanical ventilation was profitable both in terms of energy savings (at the level of 50%) and improvement in the indoor air. [ABSTRACT FROM AUTHOR]

The role of interzonal airflows is especially pronounced in naturally ventilated buildings. In such buildings, reversed airflows in the ventilation stacks might occur as well. This affects the air exchange rate and contaminant distribution in buildings. A significant increase in carbon dioxide concentration is a characteristic phenomenon for poorly ventilated rooms. This paper demonstrates the application of metabolic carbon dioxide concentration measurements for interzonal airflow estimation in naturally ventilated buildings. The presented method is based on the continuous measurements of CO2 concentration at one point in each zone. These measurements are used to estimate airflow pattern in a multizone building by applying an inverse analysis. The developed methodology employs an iterative Levenberg-Marquardt procedure to maximise the nonlinear likelihood function. The validity of the method was verified against measurements carried out in a single naturally ventilated room. Further, the method was applied to calculate the airflow pattern in two apartments in Poland, containing 4 and 6 zones. The obtained results revealed very poor ventilation in both investigated apartments and reversed airflow in exhaust ducts. The amount of fresh air entering the rooms was insufficient to ensure good indoor air quality. The developed methodology can be effectively used as a diagnostic tool to identify the potential problems with ventilation systems. [ABSTRACT FROM AUTHOR]

The article presents the results of measurements of temperature, relative humidity and CO2 concentration in six single-family houses' bedrooms located in Poland, in Wrocław and vicinity, during two climatic seasons: summer–autumn and winter. Two buildings with natural ventilation (NV) were tested, three with mechanical ventilation with heat recovery (MV) and one with hybrid ventilation (HV)—mixed mode natural and mechanical. The behavior of residents regarding opening windows was analyzed and the influence of the changing internal and external conditions on their active reactions was examined. The analysis confirms and adds to the global discourse on the key impact of user behavior on securing healthy indoor air quality in housing, regardless of ventilation system or building energy standard. A disconnect exists between the observed window opening practices and typical design principles, assuming adjustment to a given ventilation system or changing weather conditions. The observations showed that in both analyzed seasons it was possible to obtain a good quality internal environment, in terms of CO2 level, regardless of the ventilation system used in the building. However, unfavorable results were observed for one bedroom, in which the inhabitants do not adapt their behavior to local technical conditions. Taking into account the level of relative humidity (RH), much higher values were observed in the NV bedrooms in both analyzed periods. The obtained results were divided into IAQ classes in accordance with the EN 16798-1. The recorded values of the internal temperature confirm the significant influence of the location of the room in the building and the actions taken by the residents. [ABSTRACT FROM AUTHOR]

In buildings with good-quality thermal insulation of external partitions, the main component of the building's heat balance is the heat demand for ventilation. The reduction of this energy demand cannot be achieved at the expense of thermal comfort of the occupants and indoor air quality. The aim of this article is to analyze the impact of various ventilation strategy (natural and mechanical) on heating demand, thermal comfort, and CO2 concentration in a single-family house located in Poland. The benefits of using fans integrated with the earth tube were tested. The study was based on the numerical energy simulation of a multi-zone building model for the entire calendar year. Contam, EnergyPlus, and Python programs were used to perform calculations. The thermal model was validated on the results of temperature measurements in the building. To obtain the best solutions, the parameters of the systems considered have been optimized with the use of genetic algorithms. Various optimal parameters of the earth tube (diameter, length, and foundation depth) were obtained during this research. The highest number of thermal discomfort hours was obtained in the naturally ventilated building with automatic window opening. This system supplied to the rooms a large amount of cool outdoor air in winter and warm air in summer, causing instantaneous rapid fluctuations in indoor temperature. Supplementing the mechanical ventilation control system with CO2 concentration sensors resulted in a much higher amount of ventilation air supplied to the rooms compared to systems controlled only by temperature sensors, resulting in an increase in heat demand. [ABSTRACT FROM AUTHOR]

Ensuring the comfort and health of occupants is the main objective of properly functioning building systems. Regardless of the season and building types, it is the priority of the designers and building managers. The indoor air parameters affect both the well-being and health of users. Furthermore, it could impact the effectiveness of their work and concentration abilities. In hotel facilities, the guests' comfort is related directly to positive opinions or customer complaints, which is related to financial benefits or losses. The main goal of this study is the analysis of the indoor environmental quality in guests' rooms, based on the example of a hotel in Poland. The article assesses the variability of air parameters, including temperature, humidity, and carbon dioxide concentrations, and the acceptability of indoor conditions. The research was carried out in November 2020. Based on the collected data, the dynamics of changes of selected air parameters were analyzed. The article analyzes the comfort indicators inside guest rooms, including the Predicted Mean Vote (PMV) and Predicted Percentage of the Dissatisfied (PPD) index. The obtained results were compared with the optimal conditions of use to ensure the guests' comfort. As the analysis showed, the temperature and humidity conditions are maintained at a satisfactory level for most of the time. It was noticed that the CO2 concentrations temporarily exceeded the value of 2000 ppm in two of the analyzed guests' rooms, which could cause discomfort to hotel guests. In these rooms, the increase in the volume of ventilation airflow should be considered. The measured parameters dynamically varied over time, and there was no repeatability or clear patterns of variation. This is due to the individual preferences and behavior of users. A detailed analysis is extremely difficult due to the possibility of opening windows by users, the irregular presence of hotel guests in the rooms, and the inability to verify the exact number of users in the room during the measurements. [ABSTRACT FROM AUTHOR]

[Display omitted] • Children > 4 years showed slightly higher impacts than younger children. • Differences between urban/rural and winter/spring were significant. • Health impacts from cumulative metal exposures exceeded PM 2.5 impacts. • Metal effects extrapolated from animal studies show the highest uncertainties. To better understand the relation between children health and indoor air quality, we measured the concentrations of fine particulate matter (PM 2.5) and 11 metals (arsenic, cadmium, chromium, copper, iron, manganese, nickel, lead, antimony, selenium, and zinc) from air samples taken during both winter and spring, and focused on urban and rural area kindergartens of the Upper Silesia Region, Poland, typified by the use of fossil fuels for power and heat purposes. We combined related inhalation intake estimates for children and health effects using separate dose–response approaches for PM 2.5 and metals. Results show that impacts on children from exposure to PM 2.5 was 7.5 min/yr, corresponding to 14 μDALY/yr (DALY: disability-adjusted life years) with 95% confidence interval (CI): 0.3–164 min/yr, which is approximately 10 times lower than cumulative impacts from exposure to the metal components in the PM 2.5 fraction of indoor air (median 76 min/yr; CI: 0.2–4.5 × 103 min/yr). Highest metal-related health impacts were caused by exposure to hexavalent chromium. The average combined cancer and non-cancer effects for hexavalent chromium were 55 min/yr, corresponding to 104 μDALY/yr, with CI: 0.5 to 8.0 × 104 min/yr. Health impacts on children varied by season and across urban and rural sites, both as functions of varying PM 2.5 metal compositions influenced by indoor and outdoor emission sources. Our study demonstrates the need to consider indoor environments for evaluating health impacts of children, and can assist decision makers to focus on relevant impact reduction and indoor air quality improvement. [ABSTRACT FROM AUTHOR]