Although the heating water is in a non-life-saving environment, it contains a minimum of nutrients and has an elevated temperature, microorganisms can be propagated under certain conditions. Depending on their type and amount, problems with excessive occurrence of gases in the heating system, smell and corrosion may occur. The most frequent cause of the introduction of microorganisms into the heating system is the storage of pipes in the outdoor environment without their ends being blocked, and then, of course, the purity of the water that is impregnated into the system.

The paper deals with the experimental determination of heat losses of reservoirs (hot water storage tanks, heaters, heat reservoirs). It shows how the thermal loss of the tank itself, determined by the correct procedure in accordance with the standard, can be different from the loss of the reservoir connected to the thermal system.

This paper describes the method of determining the heat losses resulting from the heat transfer to the space according to ČSN EN 15316-2-1. Based on a detailed comparison of the different heating methods considered for rooms with a room height higher than 4 m, their heat-sharing efficiency is evaluated.

The article deals with the analysis of a possible solution of a non-energy residential building. The analysis shows what energy sources help to achieve a zero balance of non-renewable primary energy and what is not. In the contribution, the investment solution and the real operating costs of the energy-zero residential building compared to the current solution are shown for the selected solution and a simple payback period is set.

The article presents a concrete example of a real operational problem with the use of so-called double-walled hot water heaters. The example is aimed at destroying the reservoir of the construction system tank in the tank due to a malfunction of the operating mode.

The article summarizes the experience, the boiler control issues, boiler operating characteristics and evaluation of the boiler exchanges.

With the advent of the EU Commission Regulation 2015/1189 on the ecodesign of the solid fuel boilers, there are beginning to emerge questions and ambiguities regarding the conversion of the efficiency and emission values reported in the protocols from the testing laboratories. The EU Commission Regulation introduces new evaluation of boilers specifications, which are seasonal efficiency and seasonal emissions. The calculation of the seasonal efficiency takes into account also the electricity consumption and potential production of electricity in a cogeneration boiler. The article mentions the formulas for the conversion of the boilers specifications according to the requirements of the mentioned Regulation. It also includes a model example.

The article deals with influence of heat losses in distribution system and related cooling of heating water on the design of two-pipe counter-flow heating system. On the numerical reference model was studied the effect of distribution heat losses and cooling of the heating water on the heating system with mass flow rates designed by conventional calculation. In the following part were compared results from conventional design with design based on the numerical model which considered heat losses of the distribution system and cooling of the heating water. Mass flows rates were chosen as the compared variable, as they affect both thermal and pressure behavior of heating systems.

Revealing the cause of a faulty heating system in a residential building by over-aerating it can be far more complex than it appears at first glance. The impetus for the expert opinion was the complaint to the heating system operator that one riser of the heating system was repeatedly aerated and the heating element on the last floor was decommissioned.

The paper is focused on the issue of the pipeline networks dilatation. From the perspective of the designer, it is a very simple and well-documented issue. However, as is shown in the article, if the basic requirements are not met when designing the pipeline networks, the results can be quite fatal.

The unused chimney flue or strong wall of the chimney body offers the possibility of using it for conducting pipes etc. It is a prerequisite to keep the flue gas safety and operating mode of other installations. The article highlights the important factors of a possible decision.

This article deals with verification of function of Laddomat 21 (which mixes supply heating water with return water), verification of the time needed to heat up the thermal storage tank when using Laddomat with different thermostatic cartridges (required temperature settings) and effect of using this system on the pollutants emission in the flue gas.

The definition of what is a common part of a residential building is essential especially when modifying the building structures and eliminating defects that affect both a common part and residential units. How common parts are defined affects who finances the modifications and reconstructions of such structures and parts. The definition of common parts is based on the new Civil Code (No. 89/2012 Coll.) and on the already abolished Act on Ownership of Housing (No. 72/1994 Coll.).

The article presents a concrete example of a real operational problem with the use of so-called double-walled hot water heaters resulting from the heat-technical properties of such water heaters.

Since the combustion of solid fuels in heating boilers is attended by emissions of pollutants, in individual EU countries are gradually adopted different tightening requirements (emission and efficiency), which the appliance must meet. Requirements are targeted both the producers or importers of the combustion devices and theirs' operators. The aim of this article is to provide an overview of current and oncoming requirements and also show their comparison.

The expert analysis reveals the cause of the mechanical failure of the solar collector as a result of non-adjustment of the control valves control to the operating states of the system. Simultaneous adjustment of the control valves eliminated the safety device from the function, when the pressure increased excessively and the collector leaked.

The paper seeks to provide a comprehensive view of counter-flow two-pipe heating system from the design perspective of the temperature parameters and related small or large flow rate through the system. It analyses the work of the thermostatic control valves, zone valves and riser valves in systems with small and large flow rate and on the basis of the analysis it evaluates their advantages and disadvantages. It also deals with hydraulic balancing of heating systems and works with the defined term “sensitivity to changes in flow rate”.

The parameters and characteristics obtained from the laboratory test are used to compare products in terms of performance and efficiency. The results also serve for the correct design and evaluation of the year-round behavior of the element built into the entire thermal system.

Intermittent operation of a heat source called “on-off” affects the heat consumption for heating. The article gives a concrete example of a house for specific cycle interruption. For historically less thermally isolated house from overheating losses they are at a level of approximately 10.2% of the annual heating requirement. In a well-insulated house, this ratio falls below 5%.

The effort to achieve the highest efficiency of the combustion heat source is associated with the reduction in chimney losses, and thus reducing the exhaust temperature. The result is condensation in the boiler and flue system. It arises aggressive corrosive substances that can shorten the life of the boiler unless it has adequate construction and supports the formation of deposits that reduce efficiency and increase maintenance costs. Disproportionate increase in the efficiency with which the fuel savings are associated is then reflected in increased operating costs.