The study analyses the efficiency of a Solar Water Heating (SWH) system, potential financial savings and investment profitability. The analysis pertaining to the amount of energy generated by the collectors had been performed for the multi-family building within the span of two years. The efficiency of the system was determined by comparing the amount of energy from solar radiation incident on the surface of the collectors to the amount of energy generated by the collectors and fed to the existing Domestic Hot Water (DHW) system. The amount of energy generated by the collectors was approx. 70 GJ per year, at the efficiency of the SWH system equalling 36%. The best time for the operation of the system was the period from April to September, during which the share of generated for DHW amounted to 78%. It is reflected in the decreased consumption of gas by 6% throughout the year. Furthermore, based on the data about the efficiency and energy yield of the set of collectors, as well as data on insolation, the analysis was performed to determine the installation and operation costs and the depreciation period of the investigated SWH system.
In the light of climate changes related to global warming forecasted by scientists, preventive measures against negative impact of solar radiation on dairy cattle welfare become vital. Apart from sprinklers and fans, different forms of shading, like native trees, extension of eaves or shade screens are increasingly often mentioned. The aim of the present studies was to determine the effect of barn type and orientation on the penetration of solar radiation into sidewall stalls during summer. A non-stationary analysis was performed for 3 types of curtain-sided freestall barns most commonly used in Poland, in which a model analysis of insolation was performed taking into account geographical location of Poland, azimuth and sun angles. The obtained results allowed us to identify optimal orientation of barns and to suggest the simplest technical measures to protect sidewall stalls from solar heat gain deleterious to cows. The model analysis of stall shading demonstrated that extension of barn eaves to 1 m on the southern side reduced the insolation of stalls over even up to 90% of their area.
The thesis presents the analysis of development of selected parameters of microclimate in a standalone cellar plunged into soil. The scope of studies included measurement of air internal and external temperature and relative humidity of internal and external air. The thesis also concerns the analysis of heat exchange of cellar compartments with the surrounding soil. The studies were carried out from July 11, 2012 to July 10, 2013. The analysis of the obtained results of studies proved that the internal air temperature in the examined cellar was mainly formed by the external air temperature as well as by the surrounding soil. For 42% of storage period, the thermal conditions in the cellar plunged into soil were unfavorable which disqualifies the cellar’s purpose for storage of vegetables, e.g. potatoes. Too high temperature was observed in the initial and final period. Favorable storage conditions were experienced only in the period from December 14, 2012 to April 11, 2013. To adjust this kind facility for storage of vegetables, thermal insulation of compartments and installation of cooling units is required.
The paper presents results of studies of some indoor microclimate parameters and temperature of litter bedding in a freestall barn used to house dairy cattle in a deep-litter bedding system. The studies were conducted in the period from 22 March 2014 to 22 March 2015. The analysis of distribution of litter surface temperature showed its strong relationship with indoor air temperature. In summer, temporary exceedances of the allowable indoor air temperature by even 12 °C were noted. The studies showed a significant effect of the number of animals in the barn on litter surface temperature. In the periods when cows stayed in the barn, two zones could be distinguished: the sidewall zone 1.5 m wide at the western outside wall of the building and the inner zone encompassing the remaining part of the barn. Differences in litter temperature between these zones, when cows stayed in the barn, reached 10°C. When the building was empty and animals were on pasture, the differences between litter surface temperatures were much smaller and did not exceed 3°C.
The paper presents an analysis of the influence of the moisture content in autoclaved aerated concretes on their drying. The tested material consisted of 60 cubic samples (10 x 10cm) of fly ash aerated concrete and sand aerated concrete, types 400 and 600. The analyzed physical parameters of the samples, such as specific density, bulk density, porosity, tightness and absorbtivity, were presented in the paper. The tests revealed that the rate of autoclaved aerated concrete drying depends in the first place on its structure and the moisture content. The drying period of samples soaked with water was the shortest for the sand aerated concrete type 600. The longest drying period was observed for the samples of the fly ash aerated concrete type 600. The results of conducted analyses allowed for distinguishing two phases of autoclaved aerated concrete drying: the first - up to 10 days, when an intensive decrease in mass wetness takes place, and the second - from 10 to 25-40 days, when a slow decline in mass wetness is observed.
System zysków bezpośrednich ze słońca w budynkach mieszkalnych polega na maksymalnym pozyskiwaniu promieniowania słonecznego przenikającego przez okna i inne przeszklone przegrody. Najpowszechniejszymi systemami do biernego pozyskiwania ciepła są: okna, przegrody akumulacyjno kolektorowe, ogrody zimowe. Celem pracy była analiza trzech przyjętych rozwiązań materiałowo-konstrukcyjnych służących do biernego pozyskiwania ciepła słonecznego w modelowym budynku o konstrukcji szkieletowej pod kątem jego zapotrzebowania na energie grzewczą. Zakres badań obejmował wykonanie dokumentacji technicznej oraz niestacjonarną analizę energetyczną budynku. Jako kryterium rozstrzygające o wyborze najkorzystniejszego systemu biernego pozyskiwania energii słonecznej został przyjęty wskaźnik ilości energii którą można zaoszczędzić na 1 m2 powierzchni użytkowej budynku. Na podstawie przeprowadzonych badań stwierdzono, że najefektywniejszym systemem pozyskującym energię cieplną ze słońca są duże przeszklenia okienne na południowej ścianie budynku. Dzięki zastosowaniu takiego rozwiązania można ograniczyć zużycie energii grzewczej w budynku modelowym nawet o 14% przy jego prawidłowej lokalizacji względem stron świata.
EN
The biggest and basic advantage of the system of sun direct profits is a simple way it design and subsequently construction. It involves obtaining maximum solar radiation penetrating through windows and other glazed partition. The most common systems for the passive heat obtaining in buildings are the direct profits systems, thermal storage wall, conservatories. The aim of the study was to analyze three of the solutions adopted material and construction used for passive heat obtaining in solar model-timbered building in terms of energy demand for heating. The scope of research involved the making of technical documentation and non-stationary building energy analysis using computer programs. As the decisive criterion for selecting the most favorable passive solar energy obtaining system has been accepted indicator of the amount of energy you can save per 1 m2 of usable floor space. Based on the research it was found that the most effective energy solar heat obtaining system are large glass windows on the south wall of the model building. By using this solution you can reduce heating energy consumption in the model building by as much as 14% at its correct location relative to the world directions.
The aim of this study was to analyze the existing barns in terms of cow maintenance systems, structure and technological solutions of buildings at large dairy farms in northern Poland. The studies were conducted in northern Poland in West Pomeranian, Pomeranian, Kuyavian-Pomeranian, Warmian-Masurian and Podlaskie voivodships. The study included field inventory and questionnaire studies at some chosen farms of these voivodships.The farm size criterion was set at the herd size of 150 or more head of cattle. Based on the obtained study results and their analysis, it was established that in northern Poland the highest number of large dairy farms (41%) was located in the Kuyavian-Pomeranian voivodship and the majority of dairy farms comprised 1-3 barns built of reinforced concrete and equipped with a gravity ventilation system. In all regions prevailed farms keeping 150 - 200 head of cattle and the largest average herd size of 460 head of cattle was in the West Pomeranian voivodship. The most often barns were equipped with herringbone milking parlours (45%) for 21-25 cows milked at once and the indoor feeding table (63%).
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