No abstract

No abstract

No abstract

The presence of water disinfection by-products (DBPs) in the pool environment is a threat to the health of the users of swimming pools. Due to the mechanism of DBP formation, we are not able to prevent their presence. However, there are several ways to prevent the harmful effects of DBPs on the health of pool users; among these, various kinds of methods that result in the reduction of combined chlorine and DBPs precursors should be mentioned. And last but not least, a new approach to the design of the ventilation system for indoor swimming pools seems to be crucial for the above-mentioned purpose.

Pool water must be constantly disinfected. Chlorine compounds used to disinfect pools react with organic substances such as sweat, urine, and personal care products introduced into pool water by users and results in the formation of disinfection byproducts. Trihalomethanes (THM), including chloroform and dissolved organic carbon (DOC) concentrations, were quantified using a two-stage process: determining initial THM and chloroform levels; then searching for a cheap and easy-to-use method to improve water quality. The method proposed here to limit THM and DOC concentrations in water is controlled showering. At three swimming pool facilities, chloroform concentrations (13.8 ± 0.33 µg/L, 15.5 ± 0.44 µg/L, and 13.9 ± 0.06 µg/L) were below the threshold concentration of 30 μg/L. At a fourth facility, however, the chloroform concentration exceeded that threshold (40.7 ± 9.68 μg/L) when showering was not controlled. Those conditions improved after the introduction of a mandatory shower; concentrations of DOC, THMs, and chloroform all decreased. The chloroform concentration decreased to 29.4 ± 3.8 μg/L, the THM concentration was 31.3 ± 3.9 μg/L, and the DOC concentration was 6.09 ± 0.05 mg/L. Pilot tests were carried out at real facilities to determine whether the control of pre-swim hygiene was possible. The introduction of proper pre-swim hygiene limited the concentration of DOC in water and can lead to a healthier environment for everyone attending the swimming facility.

During the COVID-19 pandemic, many recommendations were made in the field of limiting the transmission of the SARS-CoV-2 virus, from which we can learn a lesson for determining ventilation strategies in strategic types of buildings (those whose closure during a pandemic is harmful to the economy, e.g. nurseries). The research was aimed at identifying recommendations in the field of ventilation and proposing a solution that would be applicable in existing buildings intended for the care of small children, and which would ensure the proper quality of the building environment, at the same time with low costs incurred by the owners. The outside air pollution (PM10) and the climate in winter (low air temperature) were also taken into account. A strategy was proposed based on the use of decentralized units, dedicated to single rooms, thanks to which the appropriate amount of air is supplied (per person), the air is cleaned and heated in the heat recovery exchanger. It has been shown that the use of heat recovery ensures that the costs of air heating will be significantly lower than during airing. The proposed solutions require two holes in the external wall with a diameter of 160-200mm (depending on the number of people), which guarantees the technically possible application in existing buildings. The strategy provides suitable conditions for the functioning of nurseries, but can be used in many types of buildings, in cold and temperate climates, where airing of the rooms during winter is not possible, especially in the case of locations where the quality of outdoor air is very poor. The proposed strategy may be applied during a pandemic, but also on a daily basis, because by ensuring the proper quality of indoor air, young children will have healthy and hygienic conditions for development when they are not at home.

There are different standards and regulations outlining the requirements regarding building air quality as well as in nurseries. These requirements specify air stream supplies and carbon dioxide concentration levels, both of which ensure proper indoor air quality. Mechanical ventilation should be used to maintain acceptable carbon dioxide levels. This article analyses the use of ventilation equipped with decentralized units, which helps secure the well-being of children. This paper proposes and evaluates economically affordable ventilation units. An algorithm for selecting the size of the devices is described by the supplied air stream depending on the number of children present at the nursery. A method of transferring the investment costs related to the assembly of the given units to the parents is proposed. Air quality in terms of CO2 concentrations was based on the following levels: 750 ppm, 1000 ppm, 1500 ppm. This assessment also includes the investment costs resulting from device usage and the costs of electricity consumed by the fans. These results showed the additional costs that assure the air quality improvement do not have to be high (45 PLN/month, ~10 EUR/month) per child attending the nursery. A 3% tuition increase returns the investment costs on mechanical ventilation within four years.

Air handling units are usually used to maintain the thermal and humidity parameters in indoor swimming pools that are used for lap swimming and recreation. Their use throughout the year consumes much more energy than, for example, air conditioning in residential or office buildings. Their considerable energy consumption is due to the need for their continuous operation to remove moisture gains from the evaporation of water and to heat the air and cover the heat losses of the pool. It is possible to design ventilation devices in such a way that the operating costs will be reduced, and the environmental impact will be significantly reduced. In this article, six different ventilation units in which different heat sources are used to heat the ventilation air have been evaluated; the selection of which was based on the most commonly used solutions. The results of the analysis are aimed to show which of the available heat sources is the most advantageous in terms of global and operating costs, and in terms of low CO2 emissions. Indicators of both the final and primary energy consumption, as well as the operating and global costs, were determined. The recommended solution that was chosen was the one that had both the lowest cost index (18–20% lower than most ecological sources) and the low primary energy index (8–13% higher than most ecological sources). The results showed that a heat pump in the ventilation unit proved to be the most beneficial solution. Unfortunately, this solution is rarely used due to its high investment costs (20% higher). However, the results have shown that the investment cost of using an advanced air handling unit will be recouped in only two to three years. Also, the global cost for units with a heat pump proved to be the lowest, despite high investment cost.