Paper deals with the definition of energy flexible building, its impact on the stability of the grid with the planned increasing share of energy from renewable sources and the possibility of using the heat storage capacity of building structures. Paper further analyzes the selected methodology for evaluation of the energy flexibible building and gives an example of thermally activated building structures.
The paper deals with the analysis of thermal losses of pipe distributions in the small solar system model created in the TRNSYS energy simulation tool. Attention is paid to the impact of heat loss through pipelines on the overall energy balance. Several variants of pipe lengths for one type of system have been selected. The results presented in the articles illustrate the influence of different pipe lengths on heat losses and the consequent impact on the energy balance of the monitored system.
The author draws attention to the need to pay special attention to the measurement of heat conveyed by liquids other than water. The properties of mixtures of water and different substances have different thermodynamic properties than water and if the heat meter cannot be set for other measurement conditions, the measurement error may reach up to 100% in extreme. The properties of liquids in relation to the construction of heat meters are discussed. In conclusion, the author adds recommendations, the observance of which would help to ensure measurement accuracy.
The article describes the current approach of the Czech legislation to waste incineration in households, describes the origin and principle of the method for detecting incineration or co-incineration of waste. At the end of the article, what is the subsequent procedure for demonstrating waste incineration and what sanctions are threatened by the owner of the incinerator.
Virtual models of spaces, devices, humans, and their interconnectedness with mathematical descriptions of the interactions between them allow for shorter time in finding the optimal variation. Many processes are neither realistically traceable at the micro level, and can be derived only on the basis of the consistency of simulations and real measurements at the macro level. The TZB area offers a wide range of computer simulations, as lectures at the conference.
In July 2018, a two-year monitoring of the FENIX Group a.s. in Jeseník. During this time, different battery operating modes were applied to test their capabilities to ensure the power operation of the object. This article describes the entire period in terms of energy flows in the building. The key parameters are energy consumption, supply to the grid, self-sufficiency of the building from the photovoltaic source and its local use. A number of articles have been written about the building, detailing the building and energy aspects [1, 2]. Therefore, the description of the energy economy in the building will be given only to the extent necessary for a general view of the building's energy.
The "size" of the control system has a significant impact on how individual actors in the supply chain - investor, designer, salesman and implementation technician or programmer - are approaching it. But how do you determine the size - and how do you define it at all? In terms of measurement and regulation, we can highlight two main factors: range and complexity.
As a condition for the data from the heat meter to be within the permissible tolerance field, it is correct to determine the operating conditions of the gauge and to adapt the gauge selection. Not only at the stage of designing and installing the meter, but throughout its operation. One of the critical parameters is the minimum temperature difference and the minimum flow, which changes very often after insulation of the buildings, after the modernization of the heating systems of individual apartments. In terms of accuracy, there is no difference between bills for billing purposes and gauges used to use their data to optimize the operation of heating or cooling systems.
The methodology for determining energy-neutral or energy-zero houses is different at national levels. The interest in the realization of such houses is not only influenced by the methodology but also by the market conditions in the area of moving surplus energy production from one object to another. This is an economically disadvantageous purchase price when delivering to the network. If the existing conditions in the Czech Republic are not changed, the implementation of energy-zero houses for investors will not be interesting and the potential for reduction of CO2 production will not be utilized.
The methodology for determining energy-neutral or energy-zero houses is different at national levels. The interest in the realization of such houses is not only influenced by the methodology but also by the market conditions in the area of moving surplus energy production from one object to another. This is an economically disadvantageous purchase price when delivering to the network. If the existing conditions in the Czech Republic are not changed, the implementation of energy-zero houses for investors will not be interesting and the potential for reduction of CO2 production will not be utilized.
The article compares the behavior of two-pipe heating system with counter-flow and with concurrent-flow and single-pipe heating system with bypass of radiators. It focuses on changing different parameters such as return water temperature, radiator output or temperature in the heated space when closing the control valves for radiators.
The paper introduces the changes in the Public Health Protection Act and the amendment to the Government Regulation on Protection of Health from the adverse Effects of Noise and Vibration related to the stationary sources of noise. It also describes the way of measurement and assessment of noise in the communal environment.
The article contains a summary of energy consumption, a comparison with the calculation assumptions in a particular administrative building. The object is designed with minimal energy consumption and the goal is to achieve the highest degree of energy independence using photovoltaics and battery storage. The actual course of measured energy consumption, the overall assessment for the past period, the monthly summaries for the building as a whole and the individual sub-measured energy consumption are given. The aim is to bring the issue to the professional public and to indicate the path to the solution.
The notion of a nearly zero building, usually NZEB or nZEB, is no longer a novelty. This energy standard was introduced in 2016 and is gradually expanding into family houses. There are legislation, standards, but little has been gained. That's why the authors analyzed 130 already existing family houses with different heat sources. The result is an assessment of the influence of different heat sources on the energy intensity of homes and therefore an orientation aid for decision-makers of future builders.
By replacing the non-condensing gas boiler with condensing is connected with the necessity to solve the condensate drain from the boiler into the sewer. For boilers, especially in households, it may be as simple as introducing condensate into the flushing cistern of the WC. The article discusses operational and hygienic contexts. The conclusion is that without the additional installation of a special fitting – the pipe separator into the drinking water supply to the cistern, it is a solution that is inconsistent with current regulations and cannot be recommended.
The aim of the paper is to highlight the most common mistakes in sizing of domestic hot water (hereinafter only DHW) storage tanks and heat sources for DHW preparation. The article describes two basic ways of designing: Method using heat supply and demand curves of the DHW preparation system and Method of priority DHW preparation. Sizing of the DHW storage tank should primarily correspond to the used heat source and expected hot water consumption profile. When using the heat supply and demand curve method, the designer places the greatest importance on the minimum size of the DHW storage tank (i.e. the shape of the supply curve), regardless of the potential changes in the DHW consumption profile (i.e. the demand curve). When using the so-called priority DHW preparation, the basic precondition is often neglected that the required heat output of a common heat source must comply not only with the DHW preparation system but also with other connected heat consumption points.
The issue of determining the real operational efficiency of hot-water boilers for solid fuels is increasingly being discussed. Thanks to the constantly increasing energy costs, greater emphasis is placed on the precise quantification of the economy of the operation of heat sources in project documentation and various operational analyzes. For hot water boilers, it is also becoming increasingly clear that for such studies the efficiency declared by manufacturers in the accompanying technical documentation can not be taken into account as this may often differ significantly from real seasonal energy efficiency. Particularly in times of less demand for the amount of heat produced, where there is often cyclic (intermittent) source operation, its actual efficiency may differ from that declared. In this paper I will introduce the operation of a small pellet boiler as an example.
Heat balance within any zone is the basic principle for modelling and simulation of indoor temperature. State space model offers whole mathematical details about the dynamic process, because it clarifies state variables, input signals and output signals. By determining all these parameters, Simulation becomes applicable using some software, where validation process can be carried out.
Matlab/Simulink offers effective tools to deal with state space model, and convert to other models, such as transfer function model. There are some advanced tools in Matlab to analyse the system, and specify its responses to different types of input signals.
In this paper, temperature inside a residential zone has been modelled using state space model, whereas, indoor temperature and layers temperatures are the state variables. Then, state space model has been converted to transfer function model using control toolbox in Matlab. The system then has been analysed using ltiview tool. By this tool, the basic characteristics of its responses can be determined. After that, a programmed algorithm has been proposed to design a proportional controller depending on transfer functions obtained from state space model. Finally, Simulation has been carried out using Simulink to validate the results.
