Issue 1/2024

In the article, the authors define 6 basic typological models of district heating systems (DHS), which suitably represent most heat supply systems in the Czech Republic. The categorization is based on the results of a detailed survey of the state of the heating industry in the Czech Republic in 2022. By analysing the available data, typical technological parameters of DHS are identified and further classified into the above mentioned 6 models according to po wer class, heat production, temperature level or type of consumption.

The paper deals with different designs of wall heating surfaces and presents an overview of the different products on the basis of critical research and graphic evaluation. In graphical form, it compares the specific thermal performance achieved by different wall hea ting systems.

The topic of the paper is the change in energy performance requirements for new buildings from 1. 1. 2022 compared to the previous requirements. Although it has been a long-planned change, its impact on the construction process and the resulting possibilities of construction of new buildings is significant. The paper evaluates the design options of a conventional apartment building with respect to meeting the energy performance of the building before 1. 1. 2022 and currently. The model case is solved by increasing the quality of the thermal and technical properties of the building envelope and consequently by technological modifications. Given the rising prices of energ y and labour, this is a ver y relevant issue.

Starting on 1st January 2023, on the basis of § 4 paragraph 1 of Act No. 264/2020 Coll. on the energy performance of buildings, it is necessary to calculate the energy performance of buildings or zones with cooling, humidity conditioning or electricity generation with an interval of one hour. The paper describes the basic boundary conditions in the form of climatic data and typical zone usage profiles that are recommended for this type of calculation.

The paper deals with the BIM tool, the onset of digitalisation in the Czech construction industry and the data collected during the preparation and implementation phases of building construction. Data is the subject of information management. They prove their importance in the operation and use phase of the building life cycle. By linking the building information model (or at least its non-graphical content) with the CA FM system, the better efficiency of facility management performance is supported. The aim of this paper is to highlight the importance of building data standards, data types and data storage in relation to the building information model in the context of facility mana gement.

The paper presents a new method to determine the sensible effectiveness and pressure loss of rotary regenerative heat exchangers using Computational Fluid Dynamics (CFD). It is based on CFD simulations of a single thermal wheel microchannel with a small cross-sectional area and thin walls, with cyclic inlet and outlet boundary conditions. Five different types of thermal wheels were simulated in ANSYS Fluent. The correlation model and CFD results were compared and found to be different from each other. The results of the CFD simulation were compared with measurements to prove that the proposed simulation method can predict the behaviour of the real heat exchanger as a whole. It was demonstrated that the sensible effectiveness and pressure loss of the rotary heat exchanger predicted by the CFD simulations correspond well to the measured. The proposed method can be used for the comparison of different rotary regenerative heat exchangers before their manufacturing and for verification that they meet the EU Ecodesign requirements.