Issue 2/2019

Development in the Field of Indoor Environment Engineering with a Focus on Health and Well-Being of Occupants

Abstract...

The article deals with events and people who have influenced how the indoor environment has been perceived. The emphasis is on indoor air quality and thermal comfort. In the 19th century, people were concerned about spreading illnesses in poorly ventilated buildings. Therefore, the recommended amount of outdoor ventilation air was derived from requirements of physicians. Later, the requirements of engineers prevailed and in the 20th century the recommended amount of outdoor ventilation air was set with regard to ensuring the indoor environment quality. After the oil crisis (in the second half of the 20th century) a so-called sick building syndrome phenomenon emerged, while at the end of the 20th century, the issue of sustainability come into focus. By the beginning of the 21st century, the health of occupants and the often associated work productivity are once a gain in the forefront of the interest (and importance) in the i ndoor environment field.
HENSEN CENTNEROVÁ L.66 - 71
The Issue of “Surge” and “Antisurge Control” of Turbo Compressors

Abstract...

The paper deals with the issue of turbo compressors. It focuses on the principle, modelling and prevention of so-called “surge”. The first part describes the principle of gas compression in turbo compressors and analyses the most important characteristics – of pressure, power and efficiency. Furthermore, the attention is paid to the “surge” – a negative phenomenon that occurs during the operation of turbo compressors. The last part presents the control methods of the “surge” suppression and the principle of standard control of the turbo compressor with “antisurge” regulation.
KADRLE P.72 - 76
Specifics of Solar Systems with Water

Abstract...

The paper analyses the possible year-round operation of a large-area solar systems using water as a heat transfer fluid. In order to avoid the ice formation, it is necessary to heat the water in the system during the periods with possible water freezing. The paper shows what energy demand can be expected and what factors can influence the demand.
KRAMOLIŠ P., VRTEK M.78 - 81
Insight into the Flexibility of Households

Abstract...

The article analyses the prospects for technically feasible ways of developing flexibility in conditions of common Czech households, both housing units and family houses. It focuses mainly on the importance of the accumulation of energy from renewable energy sources (RES) and the management of household consumption. It also mentions the psychological impact of remote control of energy consumption on the user. It addresses especially the technological, and not legislative, issues of the flexibility integration into the normal life of consumers.
HRZINA P.88 - 90
Comparison of the Produced Controllers for Water Heating by Photovoltaic Systems

Abstract...

The article compares, from the technical point of view, the controllers for water heating by photovoltaic systems, available on the Czech market. Regulators were borrowed from manufacturers for testing at the University Centre for Energy Efficient Buildings (UCEEB) CTU in Prague. They were powered by an electronic solar simulator with predefined profiles of the volt-ampere characteristics. The aim of the measurement was to determine the controller’s ability to monitor the maximum power point, measure the internal efficiency of the inverter, the overall capacity to transfer energy to the load, evaluate the output signal and the overall design of the controllers.
WOLF P., HRZINA P.92 - 97
Insolation Requirements and the Possibility of their Easy Verification

Abstract...

The article deals with one of the areas of building lighting technology – insolation. It describes the types of buildings for which the insolation is verified, the conditions to be taken into account in the calculations and the values of insolation requirements according to current legislation. The means of determining the position of the sun in the sky and the uncertainty of the calculations are described as well. Several model situations have been evaluated with a continuous and a limited length of the shading object. On the basis of the results, graphical tools are used to quickly verify the dependence of insolation times on the selected shading parameters.
VYCHYTIL J., JIRÁSEK F., VYCHYTIL M.98 - 106