Energy Balance of a Low Energy House with Building Structures with Active Heat Transfer Control

A qualitatively new dimension has been introduced to the issue of building structures for energy-efficient buildings by the system of Active Thermal Insulation (ATI), which is already applied in the construction of such buildings. ATI are embedded pipe systems in the envelope structures of buildings, into which we supply a heat-carrying medium with adjusted temperature, so this constitutes a combined building-energy system. This introduces the concept of an internal energy source understood as an energy system integrated into the zone between the static part and the thermal insulation part of the building structure envelope. Under certain conditions, the ATI can serve as a heat recuperator or as an energy collector for a heat pump application. ATI consists of pipe systems embedded in building structures, in which the medium circulates heated by energy from any heat source. The function of the system is to reduce or eliminate heat losses through non-transparent structures in the winter and at the same time to reduce or eliminate heat gains in the summer. It is especially recommended to apply heat sources using renewable energy sources due to the required low temperatures of the heating medium and thus shorten the heating period in the building. Also recommended is to apply ATI for the use of waste heat. Buildings with a given system show low energy consumption and therefore meet the requirements of Directive no. 2018/844/EU, according to which, from 01.01.2021, all new buildings for housing and civic amenities should have energy needs close to zero

Designing Jet Fan Ventilation for an Underground Car Park by CFD Simulations

The aim of this study was to design a fire ventilation system with impulse jet fans for an underground car park. With respect to the number of parameters affecting the spread of smoke that need to be considered, there is a good chance of miscalculations if only conventional plain calculations are used in the design process. To avoid mistakes, visualize the fluid flow, and to compare the design variants it is practical to use computational fluid dynamics (CFD). In this study, CFD simulations were used to compare alternative designs of a fire ventilation system. In one alternative the exhaust shafts were located in both parts of the car park and the jet fans were directed to the corresponding shafts. The air exchange rate was 10-times per hour. In another alternative both exhaust shafts were located on one side opposite to the main air supply, and the air exchange rate was 15-times per hour. The results showed preference of the second alternative, when the smoke was completely exhausted and the visibility improved substantially, whereas in the first alternative the car park was not sufficiently ventilated even 600 seconds after the fire had been put out. The results emphasize that proper location of elements of the ventilation system is crucial to attain high efficiency of fire ventilation

Response of peat biogeochemistry and soil organic matter quality to rewetting in bogs and spruce swamp forests

Various peatland restoration strategies developed during the last two decades have aimed to stop degradation and bring back the original hydrology, biodiversity and other peatland functions. This study evaluated progress 6-15 years after rewetting in vegetation development, physicochemical properties of peat, soil organic matter (SOM) quality and microbial activity in previously long-term drained bogs and spruce swamp forests (SSF) in comparison with pristine and long-term drained sites in the Bohemian Forest, Czech Republic. Long-term drainage led to overall ecosystem degradation, indicated by a change in vegetation composition, reduced decomposability of peat, with high content of recalcitrant compounds and decreased pH, and reduced soil microbial biomass and activity. The degradation was more pronounced in SSF, while bogs seemed to be relatively resistant to environmental changes caused by drainage. Post-rewetting progress has occurred with regard to vegetation composition, peat pH, microbial biomass and potential anaerobic CO2 and CH4 production, all of which tending towards characteristics of the pristine sites. However, overall SOM quality has not yet responded significantly, indicating that some peat properties and functions, such as C accumulation, need much longer periods of time to return to the original level.Peer reviewe

Costs Analysis of Circulation Pumps for Heating of Residential Building

Circulation pumps are mechanical devices, which are used to create the overpressure required for the transportation of a heat-transfer medium in heating technology as well as in other related technologies. In a circulation pump the mechanical energy generated by the drive machine – an electric motor - is transformed to hydraulic energy, which consists of kinetic and static energy. In the pipeline of a heating system circulation pumps represent a source of hydraulic energy (positive differential pressure), which is consumed to transport the heat-transfer medium. During the flow, the heat-transfer medium puts up resistance to the so-called passive resistors, which consist of pressure losses from friction in the pipes and pressure losses due to local resistance.In this article the authors describe the research, which is based on a case study. They analyze the effect of a circulation pumps on the investments and operating costs in a residential building. Different types of circulation pumps, ranging from the most unfavorable to the optimal, were selected

Parametric Study of Heating and Cooling Capacity of Interior Thermally Active Panels

ITAP panels - interior thermally active panels with an integrated active surface in an innovative way combine existing building and energy systems into one compact unit, and thus create combined building and energy systems. These are building structures with an internal energy source. Low heat losses, respectively, thermal gains predestine for energy-efficient buildings the application of low-temperature heating/high-temperature cooling systems such as large-area floor, wall, and ceiling heating/cooling. The main benefit of ITAP panels is the possibility of unified and prefabricated production. At the same time, they represent a reduction of production costs due to their technological process of production, a reduction of assembly costs due to a reduction of steps during implementation on the construction site and a reduction of implementation time due to their method of application

CFD Simulations – Efficient Tool for Designers of Industrial HVAC Applications

The aim of this study is to design industrial ventilation in the production hall. With respect to the many parameters which influence the appropriate proposal of industrial ventilation that need to be considered, there is a good chance for miscalculations when design the industrial ventilation. Especially when the heat loads from technology threaten the stability of construction of the building. There are two different ways of solution of aeration in the aluminium plant. There is only a natural ventilation using outside air in case of melting of aluminium and an adiabatic cooling for air inlet combined with natural ventilation. The results and practice has shown, that to use only an outside air is not sufficient and the temperature in the hall is really very high. Adiabatic cooling decreases the air inlet temperature in the production hall and improves the working conditions. A thermovision mapping of the technology was used prior to start the CFD modelling. The simulation emphasize the important effect of design and location of different elements on the functionality of ventilation proposal

Heat Recovery Variable Refrigerant Volume System Installation and Experiences from its Summer Operation

Variable refrigerant volume (VRV) systems operate on the principle of a cooling machine. They extract heat from one side and return it on the other, enabling them to function as a source of heat for both heating and hot water preparation, as well as a source of cold for cooling within a single building. These systems efficiently remove unnecessary excess heat outside and only introduce the required amount of heat from the outside into the building. With an appropriate configuration and setting, a VRV system can transfer heat in both directions within one system, eliminating the requirement for waste heat to be removed without use in the building. Instead, it is transferred to the desired locations where it is needed. This principle necessitates the adjustment of not only the refrigerant temperature but also its flow rate. Consequently, the VRV system can fulfil tasks that are otherwise handled by several individual systems in a building.A heat recovery VRV system was installed in a small retail store to extract waste heat generated by baking ovens during the baking process. This report provides a brief summary of electricity and energy consumption measurements taken during the summer period for cooling purposes. Sequential logic is observed and coherence is ensured, with active voice predominating for clearer and more direct communication. The parameters of interest include cooling setpoints, cooling outside of working hours, and capacity assessment

14. mezinárodní vědecká konference Didaktická konference 2021

Title in English: 14th International Scientific Conference Didactic Conference 2021: Proceedings Didactics of mathematics, natural sciences and vocational education represent developing areas and are a breeding ground for new ideas and approaches. In mathematics and physics, the proceedings provide an overview of the historical development of education process and the possibilities of activating students. From a practical point of view, physics and chemistry are interconnected by using simulations in teaching. Vocational education is represented from various perspectives, whether in technical education, by solving logistical problems, or educational activities in the teaching of economic subjects. Due to the current situation, there are abundant contributions on the effects of the ongoing pandemic on the educational process and distance learning

Relationship between "Ich" and "Der andere" in Améry's "Hand an sich legen"

(in English) This thesis deals with the relationship between The Self and The Other as presented in the works of Jean Améry, especially in his book about suicide. To think about the relationship between these two agents means also to think about freedom, humanity, the right to life, and the right to voluntary death. The first part of the thesis is concerned with the definitions of the relevant concepts; the second part reflects on the concept of voluntary death. It is precisely the voluntary death that can be the most radical result of the culmination of misunderstanding between The Self and The Other. For voluntary death is not only a decision not to live at this time and place but also a decision to leave this society, the others. According to Améry, the decision to commit suicide is a free, natural, and humane act. By saying that suicide is a free act Améry argues against the deterministic teachings of psychologists. Améry believes that voluntary death is a natural response to inhuman, humiliating, or for any other reason unacceptable life conditions. He thinks that voluntary death is also a humane act, as it gives men the opportunity to stop existing when there is a threat to their existence as human beings, for example when they get dehumanized like a muselman in a concentration camp. In the..