Issue 3/2018

The contribution evaluates the existing operation of the Open Garden in Brno, which was designed in a passive energy standard and put into operation in January 2013. After almost four years of operation, feedback from the users of the building was surveyed by questionnaires for summer and winter operation. The thermal comfort of the Predicted Mean Vote [1] and individual feedback on building behavior were evaluated. Furthermore, based on the measured operating data, a simple monthly energy model was constructed, the outputs of which were then compared with the measured energy consumption for heating and cooling. The calculated heat demand for heating corresponds to the measured values, but the results of the calculation of the cooling need differ significantly from the measured values. For this reason, the operation of external blinds as an active element of the energy balance was examined in more detail. Experimental evaluation of blinds operation will be part of the 2 nd part.

The article describes a new methodology for dimensioning of storage water heaters for apartment buildings based on in situ measurements in apartment buildings in Bratislava. The volume sizing of the storage heaters was determined on the basis of the results of the annual measurements of the hot water consumption, while the power input of the heaters was determined on the basis of the energy balance measurements of the hot water distribution system in residential buildings. This design methodology captures the current requirements for hot water preparation in residential buildings in the Czech Republic and also in Slovakia and it can be used as a practical aid for designers.

This paper deals with the impact of glazing ratio on thermal balance of a simple well insulated test office. First, dynamic thermal simulations of the test office were performed with variable setting of glazing ratio and the effectivity of external shading system. Then, the selected calculated outputs were depicted as a function of glazing ratio and the effectivity of shading system. Heating and cooling energy needs (energy efficiency indicators), heating and cooling peak loads (indicators of investment costs in technical systems), and the difference between maximum annual operative temperature and set-point temperature (indicator of thermal comfort) were evaluated. It was observed that the increase of the glazing ratio increased energy demands and peak heating and cooling loads of the test office. The combination of high glazing ratio and a missing or poorly operated external shading system can lead to poor thermal comfort of occupants. In conclusion, utilization of an effective external shading system increases the likelihood of thermal comfort of occupants and significantly reduces cooling energ y demand and peak cooling load.

The study deals with the measurement of microclimatic (indoor climatic) parameters and questionnaire survey in open-space offices. It describes the building, the air conditioning system and the parameters that have been assessed in the space. The paper shows the problems associated with the assessment of the thermal-humidity microclimate according to the subjective feelings of the occupants. It is an introductory work to the analysis of objective and subjective assessment in the space with uneven th ermal-humidity microclimate.

Fixed fire extinguishing systems (FFES) are currently terminated in secured areas by fixed parts (extinguishing nozzles or heads), whose design is based on a rigid connection to the inlet pipe without the possibility of any movement allowing directioniong of the extinguishing medium according to the position of the fire. However, as the fire in its incipient phase is mostly localised, it would be appropriate to apply the extinguishing medium especially to the centre of the fire and its immediate vicinity. A fire test is presented in the paper to confirm or disprove whether a fire in an early stage of development, when it is still localised, can be extinguished by a directional flow of extinguishing gas from the FFES distribution system. It was further investigated how the extinction occurs. The test was carried out on a scaled room model in the fire testing room of the Civil Engineering Center a.s. and it was focused on fire class C (methane) and extinguishing gas (nitrogen). The hypothesis that the extinguishing occurs due to the smothering effect of the extinguishing medium was not confirmed in the given case after the evaluation of the measured data. The extinguishing was most likely caused by separation of the flame from the combustible substance. The presented results relate to the conditions of the particular test and can not be generalized.

The paper deals with the topic of modelling and reliability optimization of drinking water supply systems in the village of Žabeň, using facility management tools. It is an introduction to a case study divided into three consecutive parts. The modelling process is herein understood as a modelling of risks in drinking water supply systems. The introductory article describes the water pipeline in the area of interest, the village of Žabeň, the water data reporting in the village, the weak points of the system and its failures. The system description, data reporting and evidence of failures form the basis for the risk analysis using the FMEA method with use of the technical indicators methodology.

The paper aims to provide brief information on CO2 emissions worldwide and in the Czech Republic and on their time development, related trends in the development of temperature on Earth and the role of biomass as a renewable energy source which is almost neutral in terms of the CO 2 balance.

The current era is favorable for the expansion of renewable energy sources and their integration into the energy economy of buildings for residential or commercial use. According to the long-term statistics, buildings consume about 40 % of all energy produced. At the same time, the buildings together with the industry provide a huge potential for the installation of renewable energy sources. The article presents advantages and disadvantages of particular types of the most commonly used photovoltaic systems integrated in buildings. It describes the ways to maximize the use of the installed renewable sources, the assessment of the rate of return of the particular types of photovoltaic systems, not counting the subsidy support, and evaluation of the installation complexity (both financial and technical).