Abstract. Increasingly more leisure facilities, such as water parks or indoor swimming pools are being built in Poland nowadays. In order to ensure the air quality required by standards for such leisure facilities it is necessary to fit them with effectively functioning ventilation. For the removal of excess humidity, as well as chlorine ions occurring as a result of the disinfection of water as well as the carbon dioxide emitted by people using the facility, the ventilation system needs to be appropriately designed and efficient. For this reason, studies into the air quality in such facilities were undertaken. The paper presents the causes and consequences of the inappropriate operation and maintenance of ventilation systems in swimming pools. The study found that the causes of deterioration in the technical condition of the system which was operated in an environment with chlorine ions were: an inappropriate manufacture of its components and the wrong choice of construction materials for the given environment of operation. Furthermore, failure to follow the manufacturer's guidelines for the operation and maintenance of the components of the ventilation system greatly precipitated its degradation and the occurrence of sick building syndrome in the swimming pool. Solutions were found and proposed in order to improve the efficiency of the ventilation system in the given swimming-pool facility.

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Abstract:The paper presents the results of the influence of electrolytic hydrogenation on the change of electrochemical properties of selected stainless steels and their susceptibility to the formation of galvanic hydrogen. It has been shown that the electrolytic hydrogenation of steel X5CrNi18-10 and X6Cr17 in the state of delivery, not only changes their corrosion resistance, but also contributes to the formation of galvanic hydrogen cells. Keywords: hydrogenation, corrosion potential, galvanic hydrogen cell, stainless steelThe penetration of hydrogen into metals or alloys depends on different factors including the state of material, the state of stress and strain or the environmental conditions ( Fig. 1) [1][2][3][4][5][6][7]. Its presence in the structure of metal or alloy causes adverse changes in their properties, and has very negative influence on machine performance. The degradation of mechanical properties of metals and alloys under the influence of hydrogen sorption revealed both, the change and reduction in strength and plastic properties (elongation and contraction). Hydrogen contained in metals or alloys decreases their resistance to corrosion and leads to the strong surface defect. Local differences in the concentration of hydrogen in metals or their alloys, also contribute to the formation of strong galvanic hydrogen cells (GOW) [8].Taking into consideration the fact that different types of steel (carbon, stainless steel) used for building various kinds of machines, containers, heat exchangers or pipelines are exposed to hydrogen penetration, it is necessary to examine how this penetration affects the changes in mechanical and chemical properties. Until now, most of the research has been carried out on carbon steel [9]. The research, regarding the change of resistance due to hydrogen destruction of different types of steel, will allow to build a mathematical model

One of the most commonly used construction material in industry is unalloyed steel S235 and S355. These types of steel are used for construction of ships, bridges, coastal construction, welded tanks, and in buildings. Due to the operating conditions, these types of steel may undergo hydrogen degradation in the process of manufacturing of welded structures or when operating the structures. This paper presents the results of study into resistance of selected types of non-alloy structural steels to hydrogen degradation. Tests were carried out to determine changes in mechanical properties in the static trials of stretching without hydrogen, and after saturation with hydrogen. Parallel fractographic and electrochemical studies were carried out. Hydrogen saturation was carried out at the time from 3. up to 24. hours in a solution of 0.1N H2SO4 with the addition of 2 mg/dm3 arsenic oxide (III) at an electric current density of 20 mA/cm2. The results of the tests have shown that the impact of hydrogen on the tested steels S235JR and S355J2 leads to a significant deterioration in their mechanical and electrochemical properties. At comparable concentrations of hydrogen, steel S235JR is less susceptible to hydrogen degradation and has greater corrosive resistance measured in 3% NaCl solution, in comparison with steel S355J2.