Issue 1/2018

Theoretical part of the article describes single-pipe heating systems, their different ways of configuration, their advantages and disadvantages. It is followed by practical part dealing with design of a single-pipe horizontal heating system with „riding“ connection of radia tors.

The author draws attention to the question of determining the efficiency of hot water solid fuel boilers according to the current legisla tion. The statements are supported with a practical example.

The aim of the paper is to assess to what extent can heat pump supplied in the classical configuration with the on/off power control and the heat pump with a continuous control by variation of compressor speed meet the requirements of the heating system on the amount of delivered heat and its temperature level, which change during the year.

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 hea t consumption points.

The aim of the article is to acquaint the public to the key qualitative characteristics and technical parameters of air-conditioning units and, consequently, to the current possibilities of their verification. These possibilities are certifications, which guarantee valid technical specification of the designed systems according to European and international standards and regulations, including the possibility of issuing applicable energy labels. The article presents content of the tests that precede the issuing of particular certificates, design of the logo rela ted to the certifica te and some essential rules for its use in technical specifica tions.

The correct use of atmospheric air filters for general ventilation is based on separation capabilities of filter expressed by dependence of fractional separation efficiency on particle size and on the grain size and concentration of solids in the air in the particular considered case. The paper gives an overview of the development of standardization and testing of general ventilation filters in Europe and the USA. It critically evaluates this development, namely in terms of usability of introduced characteristics of tested filters for determination of total separation efficiency and lifetime period in particular case of use. It informs about ISO 16890:2016 standard, which introduces new indicators for testing and classification of filters – fractions of atmospheric dust PM10, PM2.5 and PM1. This standard was incorporated into the EN standardization framework in December 2016 and into the CSN standardization framework in November 2017. Except the USA, the standard is expected to be widely a pplied in Europe and worldwide.

The paper discusses technical ways to eliminate legionella bacteria in the domestic hot water preparation and distribution systems. In particular, it compares the thermal disinfection with the chemical disinfection, their financial costs, the effect on the domestic water pipeline and the lifetime of the whole system of hot water preparation, under the condition of continuous fulfillment of the hygienic requirements for hot water.

The article deals with measurement of total water consumption and its distribution during the daily cycle in apartment buildings. Knowledge of the distribution of hot water consumption during the day is important for dimensioning of storage water heaters and hot water storage tanks. Based on the measurement results, a new computing relation was determined for volume sizing of hot water storage heaters or storage tanks, resulting from peak wa ter consumption.

The concept of „Internet of Things“(IoT) has certainly been heard by everybody. Popularization articles presenting the possibilities of its use frequently mention the acquisition of data from energy meters, temperature readings and alarm notifications as one of the key areas of its utilization. These are precisely the data that interests us in heating, remote controlling of air-conditioning units and other devices for conditioning and distribution of air. The article focuses on the IoT from the point of view of a heating engineer and it sho ws how it can – or cannot – be currently used in this field.