Peter Kapalo

The real and subjective indoor environmental quality in schools

Abstract Investigation of IEQ and subjective evaluation of IEQ by pupils is the main objective of this research work. For the monitoring two classrooms in primary school and two classrooms in art school were chosen. Very high CO2 levels were determined in both investigated schools. In three of four classrooms the statistically significant differences (p < 0.01) were reported between TVOC levels in autumn and spring. The recommended value for TVOC levels was exceeded in the range from 52 % to 53 % in autumn and from 52 % to 70 % in spring. Significant (p < 0.05) seasonal changes were found also for PM concentrations in each classroom. Significance difference in perception of IEQ factors between genders were observed for IAQ. This study showed a good consistency between data obtained from the measurement and data from the questionnaire study and thus, pointed to the good ability of pupils to evaluate the IEQ in their classrooms.

Examining a device for air distribution by the interaction of counter non-coaxial jets under alternating mode

The research deals with the solution of the relevant problem of increasing efficiency of air distribution by the interaction of counter non-coaxial jets for providing the standard parameters of the air in industrial premises. The mathematical model of air supply by the interaction of counter non-coaxial jets in these premises was improved. It was shown that to achieve maximum efficiency of air disctribution, it is necessary to supply the air by jets that attenuate rapidly even before entering the working area. We developed and explored the structure of the air distributor with the interaction of the counter non-coaxial jets, which provides intensive attenuation of velocity and excess temperature of the resulting airflow. The specific feature of this structure is the possibility to supply two non-coaxial inflowing jets. In this way, intensive mixing of inflowing jets with the surrounding air is provided and alternating mode is maintained. The graphic dependences were plotted and the theoretical dependences based on the conducted experimental studies were derived, which may be used in further engineering calculations. The authors developed and protected by the patent of Ukraine [12] the design of air distributor for the air supply by the interaction of the counter non-coaxial jets, as well as for supplying inflowing jets in the alternating mode. The cost-effectiveness of using the air distributor with the interaction of counter non-coaxial jets was shown, compared with alternative options, and specific indicators of the air distribution efficiency were given.

Calculating the Intensity of Ventilation in Classrooms on the Basis of Measured Concentrations of Carbon Dioxide in Slovakia - Case Study

Abstract Air quality in a classroom is very important. According to a study by Wargocki et al (2012) a shortage of ventilation in the classroom reduces the ability of students to concentrate and causes an increase in the number of errors during the elaboration of tasks. The aim of this study was to contribute to the optimization of acquisition and operating costs of HVAC equipment and to ensure hygienic requirements of air quality in the indoor environment for classrooms. An analysis of calculation methods to determine the optimal ventilation rate is carried out and the proposed methodology is compared to experimental results. Values of concentrations of carbon dioxide and ventilation rates are verified by experimental measurements. The methodology most suitable for calculating ventilation rate in Slovakia is selected based on the comparison with the results from experimental measurements. Based on this a methodology for calculating ventilation rates for classrooms is determined.

Comparing Air Temperature and Humidity in a Vestibule without and with Green Wall

The paper is a part of ongoing doctoral study focusing on interior green walls and their qualities. The paper describes living wall built in entrance hall in the laboratory of Technical University of Kosice, its construction, irrigation and vegetation; the most important segments of every living wall. The research deals with effect of green wall on air temperature and humidity in the room and compares it with air temperature and humidity in the room without green wall.

Investigation of CO2 production depending on physical activity of students

ABSTRACT This paper aims to carry out measurements of indoor air temperature, relative humidity and carbon dioxide (CO2) concentrations as well as to determine CO2 production by students and teacher during various physical activities. Two classrooms of Technical University of Kosice were selected for the research. Results of objective measurements confirmed strong correlation between CO2 concentration occupancy for all measurements. Recommended value for indoor CO2 level according to Pettenkofer (1,000 ppm) was exceeding in 60.9%. Results of this study showed the insufficient ventilation intensity in classrooms as well as obvious rise of CO2 concentration during the exams. The highest increase of CO2 was recorded during harder physical activity (run on the spot, squats, right and left side lunges, and rotating of the hips). Regarding CO2 production by respondents it can be see that it is visibly increased with increasing physical activity.

The influence of occupants’ body mass on carbon dioxide mass flow rate inside a university classroom – case study

ABSTRACT From 2014 to 2017, through the cold season, 37 experimental measurements of carbon dioxide (CO2) concentration were done inside a selected university classroom, during the same type of activity, namely written examination. Based on the data obtained from the experimental measurements, the article sought to primarily establish a correlation between the body mass of the students and the intensity of carbon dioxide releases inside the experimental classroom. This relationship was determined by using statistical analysis (general least-square estimation of the regression line). The resulting equation may be used to determine in an easier way the required outdoor air volume flow rate inside a university classroom.

Comparison of the Intensity of Ventilation at Windows Exchange in the Room - Case Study

Abstract Doing the replacement of old wooden windows in a new plastic windows, in the old buildings, we get the great reducing of the building heat loss. Simpler maintenance and attendance of window is the next advantage. New windows are characterized by better tightness. The aim of the article is determination due to the performed experimental measurements, how much more are reduce the uncontrolled ventilation that is caused of the infiltration windows. In the article there is presented the experimental measurement of indoor air quality in the room in two phases. In the first phase there is the room installed by 55 year old wood window. In the second phase there is the same room installed by new plastic window. Due to the experimental measurement of indoor air quality it is calculated intensity of ventilation - infiltration. These results of ventilation intensity are reciprocally compared.

DETERMINING THE VENTILATION RATE INSIDE AN APARTMENT HOUSE ON THE BASIS OF MEASURED CARBON DIOXIDE CONCENTRATIONS – CASE STUDY

In the construction process of modern residential buildings the aim is to achieve maximum comfort within minimum energy consumption. One of the ways to achieve this requirement is the accurate determination of the volumetric air flow rate necessary to ensure the required indoor air quality. The aim of the paper is to present a methodology for determination the volumetric air flow rate on the basis of the results obtained from experimental measurements of carbon dioxide concentrations, which were carried out inside an apartment house lived by a standard family. Based on the measured values, the mass flow rate release of carbon dioxide was calculated. Consequently, the volumetric air flow rate was calculated in two situations, during the day and during the night. The main goal of the paper is to determine the required fresh air flow rate in an occupied room, based on carbon dioxide concentration measurement, in order to maintain a comfortable level of indoor air quality. The calculated air flow rate should optimize a future investment in ventilation equipment in order to choose the proper air handling unit with low operating costs. The aim is not only to improve the energy efficiency of the ventilation system, but also to ensure a healthy indoor environment. Based on the presented research it can be stated that during the sleeping of four family members there is necessary to ensure the fresh air flow rate of 104 m 3 per hour. DOI: https://doi.org/10.3846/enviro.2017.262

Energy Analysis of Hot Water Distribution System - Interrupted Operation

At an actual increase energy price it is has impact cut-down energy requirement for preparation and distribution of hot water (HW). In the paper are presented results of exploration, where been evaluation effect interrupted operations distribution systems HW flat building. From presented analyses result - relative more savings heat is for long interrupted distribution systems and for little the number of flat in building.