Grzegorz Nawalany

Influence of Wind on Air Movement in a Free-Stall Barn During the Summer Period / Wpływ wiatru na ruch powietrza w oborze wolnostanowiskowej w okresie letnim

Abstract Use of natural ventilation in the barn should lead to optimal microclimatic conditions over the entire space. In the summer, especially during hot weather, higher air velocity cools cows, which helps to avoid heat stress. The paper presents the results of studies on the evolution of air movement in a modernized free-stall barn of the Fermbet type with the natural ventilation system during the summer period. Based on measurements of velocity and direction of air flow (inside and outside the barn) and observations of smoke indicator, the movement of air masses in different parts of the barn was identified. Significant variations of air flow at different levels of the barn were found. These differences deviate from the accepted patterns of natural ventilation, which can be found in the literature. The range of a draught and stagnant air along with the conditions in which they are built was determined. On this basis, recommendations regarding the location of barns on the plots and the improvement of ventilation in summer were made. STRESZCZENIE Użytkowanie wentylacji naturalnej w oborze sprowadza się do osiągnięcia optymalnych warunków mikroklimatycznych na całej przestrzeni użytkowej hali. W lecie, zwłaszcza podczas upałów większa prędkość ruchu powietrza ochładza krowy i umożliwia uniknięcie zjawiska stresu cieplnego. W pracy przedstawiono wyniki badań nad kształtowaniem się ruchu powietrza w zmodernizowanej oborze wolnostanowiskowej typu „Fermbet” z systemem wentylacji naturalnej podczas lata. Na podstawie pomiarów prędkości i kierunku ruchu powietrza wewnątrz i na zewnątrz obory oraz obserwacji dymów wskaźnikowych dokonano rozpoznania przemieszczania się mas powietrza w poszczególnych jej częściach. Stwierdzono duże zróżnicowanie kształtowania się ruchu powietrza w różnych płaszczyznach obory odbiegające od przyjmowanych literaturowo schematów wentylacji naturalnej. Wyznaczono strefy występowania przeciągów, zastoisk powietrza oraz warunków podczas których powstały. Na tej podstawie sformułowano zalecenia dotyczące sytuowania obór na działkach oraz poprawy działania wentylacji w lecie.

The Impact of Localization and Barn Type on Insolation of Sidewall Stalls During Summer

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.

Spatial and Temporal Distribution of Temperature, Relative Humidity and Air Velocity in a Parallel Milking Parlour During Summer Period

Abstract The research aimed at determining the most significant parameters affecting the microclimate of milking parlours, such as temperature, relative humidity and air movement in a parallel milking parlour in real operating conditions. The research was conducted in the summer period, when the risk of heat stress in cattle is higher. To check welfare of cows during milking, days with air temperature >25°C and days with temperature equal or lower than 25°C were analysed. Observation and analysis were performed for air flow in milking parlour, range of supplied air stream and how air movement affects cattle. It was observed that the irregular distribution of air movement led to the development of diverse air velocity in different zones of the milking parlour (0.2-9.0 m∙s-1). As a consequence, the conditions inside the barn were not homogenous for all the cattle. A significant effect of the cows and external air temperature (which depends indirectly on orientation of the milking parlour relative to cardinal directions) on temperature increase (approx 6°C) was concluded, with relative air humidity at the level of 85-90%, during the milking, which led to systematic decrease of microclimatic comfort for cattle. Based on the conducted research, it was concluded that the design of ventilation systems in parallel milking parlours should be preceded by increased research not only on ventilation system efficiency but also on the distribution of flow ventilated air.

The impact of barriers inside a herringbone milking parlour on efficiency of the ventilation system.

Abstract The research aimed at establishing the pattern of air movement inside a 2×10 herringbone milking parlour equipped with supply mechanical ventilation. Observations and analyses were made for the streams of air supplied to the parlour, their movement pattern and spread range. Also, temperature and relative air humidity after and before evening milking routine were measured. It has been concluded that barriers installed inside the milking parlour play a significant role in creating unfavourable microclimatic conditions during milking, particularly for the last group of cows. The study points out possible threats to animal welfare and operator’s working conditions. Based on the conducted experiments, the paper defines recommendations for proper design of ventilation systems inside herringbone milking parlours. Streszczenie Celem pracy było zbadanie rozkładu ruchu powietrza w hali udojowej typu „rybia ość” 2×10 z wentylacją mechaniczną nawiewną. Obserwacjom i analizie poddane zostało kształtowanie się strug powietrza nawiewanego do hali i ich zasięg. Określono również temperaturę i wilgotność względną powietrza przed i po doju wieczornym. Stwierdzono bardzo duży wpływ elementów wygrodzeń hali udojowej na tworzenie niekorzystnych warunków mikroklimatycznych w trakcie doju, zwłaszcza dla ostatniej grupy krów. Wskazane zostały zagrożenia dla dobrostanu zwierząt podczas doju oraz komfortu pracy dojarza. Na podstawie przeprowadzonych badań określono zalecenia dotyczące projektowania systemów wentylacyjnych w halach udojowych typu „rybia ość”.

DEVELOPMENT OF SELECTED PARAMETERS OF MICROCLIMATE IN A STAND ALONE CELLAR PLUNGED INTO SOIL

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.

Analysis of Hygrothermal Conditions of External Partitions in an Underground Fruit Store

The paper presents the analysis of hygrothermal conditions of external partitions in an underground fruit store. The results of measurements of temperature and humidity of the indoor and outdoor air as well as the surface surrounding temperature and the temperature of the air surrounding the store constituted the boundary conditions for the hygrothermal calculations. The paper presents the calculation of the distribution of the temperature and humidity on the ground floor, the wall contacting the ground, the wall contacting the outside air, and the ceiling above the storage chamber. The heat and moisture calculations have shown high risk of condensation submerged in non-insulated external walls. The condition of the adaptation of a traditional cold store to a simple and atmosphere controlled cold one is to increase the thermal resistance of the partitions. Such a solution will let cut the energy demand in those types of agricultural buildings.

Measurements and calculations of temperature in the ground and in assemblies adjacent to an intermittently heated basement

Measurements and calculations of temperature in the ground and in assemblies adjacent to an intermittently heated basement