Efficacy of warming systems in mountain rescue : an experimental manikin study

Mountain accident casualties are often exposed to cold and windy weather. This may induce post-traumatic hypothermia which increases mortality. The aim of this study was to assess the ability of warming systems to compensate for the victim’s estimated heat loss in a simulated mountain rescue operation. We used thermal manikins and developed a thermodynamic model of a virtual patient. Manikins were placed on a mountain rescue stretcher and exposed to wind chill indices of 0 °C and - 20 °C in a climatic chamber. We calculated the heat balance for two simulated clinical scenarios with both a shivering and non-shivering victim and measured the heat gain from gel, electrical, and chemical warming systems for 3.5 h. The heat balance in the simulated shivering patient was positive. In the non-shivering patient, we found a negative heat balance for both simulated weather conditions (- 429.53 kJ at 0 °C and -1469.78 kJ at - 20 °C). Each warming system delivered about 300 kJ. The efficacy of the gel and electrical systems was higher within the first hour than later (p < 0.001). We conclude that none of the tested warming systems is able to compensate for heat loss in a simulated model of a non-shivering patient whose physiological heat production is impaired during a prolonged mountain evacuation. Additional thermal insulation seems to be required in these settings

Assessment of Indoor Air Parameters in Building Equipped with Decentralised Façade Ventilation Device

The study contains an analysis of a decentralised unit installed in a building façade, where air supply and exhaust cycles are swapped by proper positioning of dampers. The analysis was carried out in real conditions in an office building. The Computational Fluid Dynamics (CFD) simulation is an important element of the system design, and has become more and more widely used. Simulation of the analysed unit has shown air stream distribution in a room. Moreover, it allowed for determination of indoor air temperature. Completed analysis and CFD simulations allow for the observation that façade ventilation systems provide a good way to improve the indoor microclimate, as they effectively reduce air pollution. The decentralised façade ventilation unit reduced the carbon dioxide concentration to a level lower than 1000 ppm and maintained the indoor air temperature in the range of 19.5–22 °C. The error for CFD simulation equals 0.5%, which is not much. The results of research and analysis show that the highest reduction of carbon dioxide concentration occurred when supply/exhaust time equalled 10 min. At the same time, when supply/exhaust time equalled 10 min, the indoor air temperature was the lowest of the recorded values

Review of IAQ in Premises Equipped with Façade–Ventilation Systems

Poor indoor air quality affects the health of the occupants of a given structure or building. It reduces the effectiveness of learning and work efficiency. Among many pollutants, PM 2.5 and 10 dusts are extremely important. They can be eliminated using mechanical ventilation equipped with filters. Façade ventilation devices are used as a way to improve indoor air quality (IAQ) in existing buildings. For their analysis, researchers used carbon dioxide as a tracer gas. They have shown that façade ventilation devices are an effective way to improve IAQ, but require further analysis due to the sensitivity of façade ventilation devices to the effects of wind and outdoor temperature. In addition, legal regulations in some countries require verification in order to enable the use of this type of solution as a way to improve IAQ in an era characterised by the effort to transform buildings into passive houses (standard for energy efficiency in a building)

Heat Recovery Using PCM in Decentralised Façade Ventilation

A study of heat recovery in a façade ventilation unit was carried out under laboratory conditions using a climate chamber that allowed stable outdoor and indoor conditions to be simulated. The unit, equipped with a reversible fan and a chamber for the heat exchanger, controlled by an automation control system, was designed to exchange air in the room by alternating supply and exhaust cycles of specific durations. Three types of heat exchangers were tested, which were filled with different phase change materials, in order to estimate the efficiency of the façade ventilation unit in terms of its heat recovery capability. The efficiency of the unit was determined based on the temperature efficiency of heat recovery for 144 setting combinations. The best efficiency results between 73.56% and 76.29% were obtained with a solution using a heat exchanger consisting of cylinders with an external diameter of 10 mm and a wall thickness of 1 mm filled with jojoba oil in a one minute cycle. The tests confirmed that the heat exchangers, which are part of the façade ventilation unit, fulfil their function and allow heat recovery from the exhaust air to pre-heat the supplied air. The study complements the existing scientific knowledge on the efficiency of heat exchangers filled with phase change material, operating in winter conditions with work cycles up to 5 min

Wpływ ruchu drogowego na jakość powietrza wewnętrznego

The quality of air that people breathe has become a very important parameter of quality of life. Pollution contributes to numerous diseases, problems with the absorption of knowledge, and also reduces work efficiency. The article attempts to find the relationship between road traffic and indoor air quality. The parameter used to assess air pollution was particulate matter (smog). The research was carried out in three localisations with different traffic volumes, in three places for each localisation, in the summer, autumn, and winter periods. It was found that in areas with heavy road traffic, this traffic causes an inflow of pollutants into the rooms. In low-traffic localisations, sources other than road traffic have a greater impact on the indoor air quality, especially in the cool periods (autumn, and winter)Jakość powietrza, jakim oddycha człowiek, stała się bardzo istotnym parametrem jakości życia. Zanieczyszczenia przyczyniają się do licznych zachorowań, problemów z przyswajaniem wiedzy, a także obniżają wydajność pracy. W artykule podjęto próbę odnalezienia zależności pomiędzy natężeniem ruchu drogowego i jakością powietrza wewnętrznego. Parametrem, który wykorzystano do oceny zanieczyszczenia powietrza, był pył zawieszony (smog). Badania przeprowadzono w trzech lokalizacjach o różnym natężeniu ruchu, w trzech miejscach dla każdej lokalizacji, w okresach lato, jesień i zima. Stwierdzono, że w lokalizacji o dużym natężeniu ruchu pojazdów ruch ten powoduje napływ zanieczyszczeń do pomieszczeń. W lokalizacjach o małym natężeniu ruchu większy wpływ na jakość powietrza wewnętrznego mają inne niż ruch drogowy źródła, szczególnie w okresach chłodnych (jesień, zima)

Influence of Masks Protecting against SARS-CoV-2 on Thermal Comfort

Due to the spread of the SARS-CoV-2 virus, most countries have tightened their public health policies. One way to limit the spread of the virus is to make mouth and nose cover compulsory in public spaces. The article presents the impact of wearing masks on the perception of thermal comfort. The following masks were analysed: FFP2, cotton, medical, PM2.5, half-face protective shield plastic and full-face protective shield plastic. The research was carried out for two scenarios of an ambient temperature: −20 and 30 °C. A thermal manikin was used for the tests. In the case of when a temperature equals 20 °C, the dry masks increase comfort, both general and local, while wet masks reduce comfort. On the other hand, at 30 °C, only wet masks do not increase discomfort. In addition, moist masks require less heat flux to achieve a certain skin temperature. However, it should be remembered that it is not advisable to wet the masks from the health point of view

Jakość powietrza w wielorodzinnych budynkach mieszkalnych

The applicable legislation connected with the natural ventilation are ambiguous and sometimes contradictory. This leads to serious problems with natural ventilation. In most cases malfunction of the natural ventilation is due to the insufficient stream of air from the outside. The research showed that the microclimate is influenced not only by the incoming air stream, but also by the layout of the air supply.Obowiązujące aktualnie przepisy prawne regulujące zagadnienia wentylacji naturalnej&nbsp; [1], [2], [3] w wielu obszarach są niejednoznaczne, a niekiedy wręcz sprzeczne. Sytuacja taka prowadzi do stosowania rozwiązań powodujących poważne zaburzenia w działaniu wentylacji grawitacyjnej. W dużej części budynków zaburzenia te są wynikiem dostarczania do pomieszczeń zbyt małej ilości powietrza zewnętrznego. Jak wykazały badania, ze względu na kształtowanie warunków mikroklimatu wnętrz, podstawowe znaczenie ma nie tylko wielkość dostarczanego strumienia powietrza zewnętrznego, ale również rozmieszczenie elementów doprowadzających to powietrze

Assessment of Thermal Comfort in Rooms Equipped with a Decentralised Fa&ccedil;ade Ventilation Unit

Thermal comfort affects not only the well-being of the occupants of a building but also the effectiveness of their learning and work efficiency. It can be disturbed if the ventilation airflow is increased when improving indoor air quality. When natural ventilation is used in the fall and winter period, the supply air temperature is low, resulting in a lack of thermal comfort. In existing buildings, there is often no place for mechanical ventilation; hence, decentralised fa&ccedil;ade ventilation units are increasingly used. The article presents an analysis of thermal comfort in rooms with this type of unit equipped with heat recovery exchangers of different efficiencies. Studies have shown that the alternating supply/exhaust airflow and the related unevenness of air streams flowing through the heat accumulator cause an inflow of low-temperature air, resulting in thermal discomfort. The highest value of the PMV index was &minus;1.6, and the lowest was &minus;4.1, which means that 54.8 to 100% of the occupants are dissatisfied with their thermal comfort. This means there is a need to change the construction of inlet/exhaust vents so that the stream of supply air is not directly parallel to the floor. In addition, the use of an air heater should be considered

Assessment of Thermal Comfort in Rooms Equipped with a Decentralised Façade Ventilation Unit

Thermal comfort affects not only the well-being of the occupants of a building but also the effectiveness of their learning and work efficiency. It can be disturbed if the ventilation airflow is increased when improving indoor air quality. When natural ventilation is used in the fall and winter period, the supply air temperature is low, resulting in a lack of thermal comfort. In existing buildings, there is often no place for mechanical ventilation; hence, decentralised façade ventilation units are increasingly used. The article presents an analysis of thermal comfort in rooms with this type of unit equipped with heat recovery exchangers of different efficiencies. Studies have shown that the alternating supply/exhaust airflow and the related unevenness of air streams flowing through the heat accumulator cause an inflow of low-temperature air, resulting in thermal discomfort. The highest value of the PMV index was −1.6, and the lowest was −4.1, which means that 54.8 to 100% of the occupants are dissatisfied with their thermal comfort. This means there is a need to change the construction of inlet/exhaust vents so that the stream of supply air is not directly parallel to the floor. In addition, the use of an air heater should be considered

Próba poprawy jakości powietrza wewnętrznego w przedszkolu

The article demonstrates the results of research on the indoor air quality (IAQ) in one of chosen preschools. In such facilities, the standard solution is a system of natural ventilation. Only a small percentage of such buildings is equipped with a mechanical ventilation system with adjustable parameters of the microclimate. The article presents the results of indoor air quality in the local preschool located in Kielce. In the present facility natural ventilation system was used. Preliminary studies confirmed the poor quality of&nbsp;indoor air in a subjected building. During the study, two improvements aimed at improving air quality were proposed. The first improvement was to increase the supply air stream. The&nbsp;second one concerned the installation of equipment for the treatment of indoor air. The&nbsp;results indicate that under certain guidelines it is possible to improve indoor air quality. As an indicator of indoor air quality, concentration of carbon dioxide was adopted. In&nbsp;addition, microbiological tests were performed indoors.W artykule przedstawiono wyniki badań nad jakością powietrza wewnętrznego (IAQ) w jednym z wybranych przedszkoli. W obiekcie zastosowany został system wentylacji grawitacyjnej. Wstępne badania potwierdziły niską jakość powietrza wewnętrznego w podmiotowym budynku. W trakcie badań zaproponowano dwa usprawnienia mające na celu poprawę jakości powietrza: zwiększenie strumienia powietrza nawiewanego oraz, w drugiej kolejności, montaż urządzeń do uzdatniania powietrza wewnętrznego. Uzyskane wyniki badań wskazują, że wprowadzone usprawnienia wpływają na poprawę jakości powietrza wewnętrznego