Danica Košičanová

SHORT-TERM MEASUREMENTS OF INDOOR ENVIRONMENTAL QUALITY IN SELECTED OFFICES – CASE STUDY

Decent quality of indoor air is important for health and wellbeing of building users. We live, work and study in indoors of various types of buildings. Often people are exposed to pollutants at higher concentrations than these that occur outdoors. Continual investigation of indoor air quality is needed for ensuring comfort and healthy environment. Measuring and analysis of occurrence of physical, chemical and biological factors is the first step for suggestion of optimization measures. Inside school buildings there are often inadequate indoor climate conditions such as thermal comfort parameters or ventilation. The aim of this study was determination of indoor environmental quality in selected offices in the building of elementary school in Slovakia. The values of operative temperature were not within the optimum range of values for the warm period of the year in one of the monitored offices. The intensity of illumination was lower in the two offices. Low levels of particulate matters were measured except the one office where permissible value was exceeded by 7.6%. DOI: https://doi.org/10.3846/enviro.2017.266

Build-in Transparent Collector Construction

There are several ways to utilize renewable energy sources. Collectors are well known as one of the oldest build-in or post-mount construction at buildings. This paper presents idea of transparent sun collector based on insulation glass unit, with inner and outer liquid circulation. The heat absorbed from the sun in inner circuit liquid is transferred and transmitted by heat exchanger to the secondary circuit. Where energy can be stored or used in preheating devices in hot water delivery systems. This system can be applied in buildings with huge transparent or non-transparent glass based facades with suitable needs for hot water for example in administrative buildings, swimming pools, gyms etc. Research at current state deals with mechanical construction of window and prepares laboratory tests and build in measurements of construction itself.

The Energy Performance Model of Mechanical and Natural Ventilation

The paper deals with the energy efficiency of the ventilation systems (ventilation units) in different design alternatives (with heat recovery, without recovery, effective fans, etc.…). The alternatives of operation of the mechanical and natural ventilation system at intervals during the day are presented. The calculation of the airflow was executed in accordance with laws and standards valid in the EU and Slovakia (EN 15251, EN 13779, STN 730540, etc.). A large potential for energy savings in the Slovak building generally, due to the fact that majority of the buildings were constructed before 1989, before first important requirements for energy performance and savings of building.

Analysis of the Solar Radiation Impact on Cooling Performance of the Absorption Chiller

Abstract Absorption cooling at low power is a new technology which has not yet been applied to current conditioning elements. This paper analyzes the various elements of solar absorption cooling. Individual states were simulated in which working conditions were set for the capability of solar absorption cooling to balance heat loads in the room. The research is based on an experimental device (absorption units with a performance of 10kW) developed at the STU in Bratislava (currently inputs and outputs of cold sources are being measured). Outputs in this paper are processed so that they connect the entire scheme of the solar absorption cooling system (i.e. the relationship between the solar systems hot and cold storage and the absorption unit). To determine the size of the storage required, calculated cooling for summer months is considered by the ramp rate of the absorption unit and required flow rate of the collectors.

Solar Cooling in Slovakia

Up to now, developed absorption refrigeration units with a great power from 30 to 6000 kW were not usable for smaller objects but only for the industrial buildings and the objects of a major character. The development of the sorption cooler with low-power (2-20kW) is a modern subject of research. One of the possibilities of alternative energy production is to use the Sun as an inexhaustible source of energy to power absorption unit. The research is based on an experimental device (absorption units with a performance of 10kW) developed at the STU in Bratislava (currently inputs and outputs of cold sources are being measured). Outputs in this paper are processed so that they connect the entire scheme of the solar absorption cooling system (i.e. the relationship between the solar systems hot and cold storage and the absorption unit).

Water-Filled Window: Vision of Use in Middle Europe Region

This paper deals with a novel system of glazing and presents a water filled window or more precisely window with water flow in cavity within its one year performance. The paper also provides a description of basic principles of functioning and variability in concepts of the window. The results show that the indoor room heat gain can be reduced and this system could be used as a pre-heated water source. There is a great energy-saving potential in applications with these systems, especially in buildings with large glass surfaces which make use of hot water, like gyms, swimming pools, hotels etc.

The Minimum Ventilation Intensity Research Using Selected Parameters

The air ventilation rates defined in Standard STN EN 15 251:2007 present air change rate in which the objective benefit of proper selection of ventilation system and air distribution scheme is lost (erased) in relation to IAQ [1,2]. With help of sensory evaluation in research the total minimum ventilation rate was estimated. It was reason how to determine major boundary condition (air quantity = air ventilation rate) for minimizing of responsibility size of air quantity (quantitative component of ventilation) and maximize the impact of the choice of distribution scheme and the distribution element (qualitative component of ventilation) for transfer and distribution of pollutants in research. The total air ventilation rate for next experimental measurements was established as the intersection of three air ventilation rates according to research harmonogram. This air ventilation rate was necessary to supply to occupant to experimental classroom and also as input value to CFD simulations.

The Effective Use of Renewable Energy Sources and Advanced Technology of Environment Systems in Public Buildings

Nowadays, choosing of heating source is emphasized. On the market there are different types of heat sources, which need to be properly designed to the required heating output. Finally, it is necessary to take into account the possibilities of fuel burning as well as heat transfer substance. Heating system is dependent on regional weather conditions, where the building is located. All these factors ultimately, with proper design of the heat source, could reduce operating costs in the heating season. Currently in the design of the heating system, there are taken into account the greatest possible energy savings. It is therefore to encourage bigger utilization of renewable energy sources.Currently has the highest proportion of total energy consumption in the buildings, energy for heating. For this reason, the expert and research community seeks to reduce energy consumption at the lowest possible value. For this purpose, people are starting to apply renewable energy sources. These devices using renewable energy sources convert energy from the environment. Most of them are transforming energy from the sun, earth, water and air. This energy is then used directly for heating. In this article we will more closely deal with transforming solar energy into electricity using photovoltaic panels and we will focus on the interaction between the photovoltaic system and heating and cooling system, under certain conditions. Produced electric energy is used for heating system in the school building in Spišská Nová Ves in Slovakia.