Tag Archives: ventilation

890–899 M.O. Vilela, R.S. Gates, M.A. Martins, M. Barbari, L. Conti, G. Rossi, S. Zolnier, C.G.S. Teles Junior, H.H.R. Zanetoni, R.R. Andrade and I.F.F. Tinôco
Computational fluids dynamics (CFD) in the spatial distribution of air velocity in prototype designed for animal experimentation in controlled environments
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Computational fluids dynamics (CFD) in the spatial distribution of air velocity in prototype designed for animal experimentation in controlled environments

M.O. Vilela¹*, R.S. Gates², M.A. Martins¹, M. Barbari³*, L. Conti³, G. Rossi³, S. Zolnier¹, C.G.S. Teles Junior¹, H.H.R. Zanetoni¹, R.R. Andrade¹ and I.F.F. Tinôco¹

¹Federal University of Viçosa, Department of Agricultural Engineering, Av. Peter Henry Rolfs, s/n Campus University of Viçosa CEP: 36570-900, Viçosa, Minas Gerais, Brazil
²University of Illinois at Urbana-Champaign, Department of Agricultural and Biological Engineering, 1304 West Pennsylvania Avenue 61801, Urbana, USA
³University of Florence, Department of Agriculture, Food, Environment and Forestry, Via San Bonaventura, 13, IT50145 Firenze, Italy
*Correspondence: monique.vilela@ufv.br; matteo.barbari@unifi.it

Abstract:

Maintaining a comfortable and productive thermal environment is one of the major challenges of poultry farming in tropical and hot climates. The thermal environment encompasses a number of factors that interact with each other and reflect the actual thermal sensation of the animals. These factors characterize the microclimate inside the facilities and influence the behaviour, performance and well-being of the birds. Thus, the objective of this study is to propose and validate a computational model of fluid dynamics to evaluate the spatial distribution of air velocity and the performance of a system designed to control air velocity variation for use in experiments with birds in controlled environment. The performance of the experimental ventilation prototype was evaluated based on air velocity distribution profiles in cages. Each prototype consisted of two fans coupled to a PVC pipe 25 cm in diameter, one at each end of the pipe, with airflow directed along the entire feeder installed in front of the cages. The contour conditions considered for the simulation of airflow inside the cage were air temperature of 35 °C at the entrance and exit of the cage; air velocity equal to 2.3 m s-1 at the entrance of the cage; pressure of 0 Pa. The model proposed in this study was representative when compared to the experimental measurements, and it can be used in the study of air flow behaviour and distribution for the improvement of the prototype design for later studies.

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1720-1727 P. Kic, L. Ruzek and E. Popelarova
Concentration of air-borne microorganisms in sport facilities
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Concentration of air-borne microorganisms in sport facilities

P. Kic¹*, L. Ruzek² and E. Popelarova²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamycka 129, CZ165 21 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Microbiology, Nutrition and Dietetics, Kamycka 129, CZ165 21 Prague 6, Czech Republic
*Correspondence: kic@tf.czu.cz

Abstract:

This paper is focused on the microclimatic research in several buildings and rooms used for sport at the University. The attention is paid mainly to the problems of dimensions of space, capacity and activity of sportsmen, and influence of space ventilation. The air samples for microbiological analyses were taken by the microbial air sampler Merck Mas-100 Eco and cultivated by potato-dextrose agar and nutrient agar. Captured microorganisms, are expressed as colony forming units per m3 (CFU m-3). Measurement results showed that bacteria average quantity was statistically significantly less without students (562 CFU m-3) than with students (1,024 CFU m-3). The students inside the rooms increased the bacteria concentration. From this point of view the ventilation is not adequate for the removal of bacteria from ventilated spaces. From the results we can conclude that the great importance on the air quality in terms of a specific bacteria concentration has the specific volume of the room per one athlete. The worst situation is in rooms with the smallest volume, which has the largest biological load of the space. The lowest quantity of bacteria was in the swimming pool all year round (152 to 300 CFU m-3). The opposite situation was in average quantity of filamentous fungi, which was with students and ventilation (57 CFU m-3) and without students but without ventilation (109 CFU m-3). The pollution of air by fungi was higher without ventilation.

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2236–2246 R. Zewdie and P. Kic
Substantial factors influencing drivers’ comfort in transportation
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Substantial factors influencing drivers’ comfort in transportation

R. Zewdie¹* and P. Kic²

¹University of Life Sciences in Prague, Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcká 129, CZ165 00 Prague 6, Czech Republic
²Czech University of Life Sciences in Prague, Faculty of Engineering, Department of Technological equipment of buildings, Kamýcká 129, CZ165 00 Prague 6, Czech Republic
*Correspondence: zewdie@tf.czu.cz

Abstract:

Research shows that driver stress is associated with workload and fatigue, and an inappropriate microclimate in the driving cabin can have an impact on overall driver’s safety. The aim of this scientific study is to examine whether driver stress, across various urban and field drive conditions, can affect performance in a confined environment and whether the natural breathing process can also compound these effects and aggravate health hazards. This paper will address the influencing parameters associated with driver comfort of everyday job occupations in the urban communication network of Prague city public transport. In this research paper the authors will characterize cardinal components directly accountable to the safe operation elements; the concentration of carbon dioxide (CO2) and the relative humidity (Rhi) in the driving cabin, affecting the contentment of the drivers comfort while performing their duties. Similar inquiries were carried out on ventilation emphasis and air intake impact in drivers’ cabin, recommending a design to minimize safety problems associated with comfort. Data on the concentration of carbon dioxide and internal relative humidity in the respective cabins have been collected carefully for detailed analysis. This research paper is the outcome of these findings.

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1014–1023 M. Hromasová, P. Kic, M. Müller and M. Linda
Evaluation of quality and efficiency of ventilation equipment by scanning electron microscopy
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Evaluation of quality and efficiency of ventilation equipment by scanning electron microscopy

M. Hromasová¹*, P. Kic², M. Müller³ and M. Linda¹

¹Czech University of Life Sciences in Prague, Faculty of Engineering, Department of Electrical Engineering and Automation, Kamýcká 129, CZ165 21 Prague, Czech Republic
²Czech University of Life Sciences in Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
³Czech University of Life Sciences in Prague, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: hromasova@tf.czu.cz

Abstract:

The aim of this research is an evaluation of the quality and function of ventilation equipment in basement rooms. There was analysed the function of ventilation system in relation to the quality of outdoor and indoor environment. The concentration of air dust was measured by exact instrument DustTRAK II Model 8530 aerosol monitor inside and outside the building. Using the special impactors the PM1, PM2.5, PM4, PM10 size fractions were also measured. Particles separated from the ventilation equipment were examined with SEM (scanning electron microscopy) using a microscope TESCAN MIRA 3 GMX. Obtained results of measurements were evaluated by statistical instruments and concentrations of different size of dust particles were analysed. The size of particles outlet the ventilation equipment was ca. of 55% lower than the size of the particles inlet the ventilation equipment. The difference in tested sizes of the dust particles in the ventilation equipment and outlet the ventilation equipment, i.e. in the place of cleaned air inlet into the basement room, was statistically proved. The diversity of impurities caught by the ventilation equipment and impurities moving in the air in the tested room is obvious from the results of SEM analysis.

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1034–1042 A. Krofová, P. Kic and M. Müller
Influence of dust pollution in the laboratory on the strength of adhesive bond
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Influence of dust pollution in the laboratory on the strength of adhesive bond

A. Krofová¹*, P. Kic² and M. Müller¹

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department Material Science and Manufacturing Technology, Kamýcká 129, CZ 165 21, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21, Czech Republic
*Correspondence: kofovaa@tf.czu.cz

Abstract:

The main aim of this paper is to evaluate the influence of microclimate conditions on the bond strength in the research laboratory in the Faculty of Engineering at the Czech University of Life Sciences Prague. The main attention is paid especially to the contamination of the working environment with dust particles. In the frame of this research the concentration and size of dust particles in the air was measured by the aerosol monitor DustTRAK II Model 8530 with impactors for measurement of size fractions PM1, PM2.5, PM4 and PM10. The adhesive bonds were created according to the ISO standards from Duralumin material specimens with different type of twocomponent epoxy adhesives under different conditions of ventilation (0%, 50% and 100% of ventilation rate). The tensile strength of created specimens was measured by universal testing machine for tensile strength measurement – LABTest 5.50ST. The results of measurement were evaluated by statistical methods and summarized in the conclusions. There is no significant difference in the strength of the bond when applied various performance of ventilation.

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75–81 P. Kic
Dust pollution in the sport facilities
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Dust pollution in the sport facilities

P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Technological Equipment of Buildings, Kamycka 129, CZ 16521 Prague,
CzechRepublic; e–mail: kic@tf.czu.cz

Abstract:

The aim of this paper is to present the results of microclimatic research focused on the dust pollution in several buildings and different rooms used for sport activities at the University. The attention is paid mainly to the problems of dimensions of space, capacity and activity of sportsmen, and influence of space ventilation. In the frame of this research the concentration of air dust was measured by the exact instrument DustTRAK II Model 8530 aerosol monitor. Using the special impactors the PM1, PM2.5, PM4, PM10 size fractions were also measured. Obtained results of measurements were evaluated and concentrations of different size of dust particles were analysed. Results of different indoor conditions were generalized. Based on the results of measurements practical recommendations for the design, use and ventilation of these types of buildings were summarised in the conclusions.

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261-268 M. Rajaniemi, M. Turunen and J. Ahokas
Direct energy consumption and saving possibilities in milk production
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Direct energy consumption and saving possibilities in milk production

M. Rajaniemi, M. Turunen and J. Ahokas*

University of Helsinki, Faculty of Agriculture and Forestry, Department of Agricultural Sciences, PL 28 (Koetilantie 5), 00014 Helsingin yliopisto, Finland; *Correspondence: jukka.ahokas@helsinki.fi

Abstract:

Direct energy consumption in milk production varies largely because of machinery, production systems, working habits and maintenance. There are good possibilities to save energy in milk production. The magnitude of energy savings are in the order of tens of percent, which means that energy saving potential is quite high. Energy saving can be achieved with efficient system and machinery choices. Also adjustments and maintenance have an effect on energy consumption. To save energy the farmers should have means to measure energy and follow energy consumption. There should also be more information of energy saving possibilities and machinery energy consumptions.

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235-242 M. Zajicek and P. Kic
Improvement of the broiler house ventilation using the CFD simulation
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Improvement of the broiler house ventilation using the CFD simulation

M. Zajicek¹ and P. Kic²

¹Institute of Information Theory and Automation, The Academy of Science of The
Czech Republic, v.v.i., Pod vodarenskou vezi 4, 182 00, Prague 5, Czech Republic

²Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, 165
21, Prague 6, Czech Republic

Abstract:

The need for an exact control of the indoor conditions in buildings is the main reason for different simulation methods as a help for designers and researchers. This paper is focused on the numerical analysis of ventilation of building for broilers during the summer period with the use of computer fluid dynamics (CFD) software from Fluent Inc. The summer period is particularly critical. This paper presents the results of measurement and CFD analysis of the flow pattern, thermal state and concentration of pollutants inside the broiler house. Calculation respected the Czech standard. Final results show the improved arrangement of ventilation. There are a lot of aspects which has to be included in the process of improving the function of an existing broiler house ventilation system. It is commonly required to find an acceptable balance between the financial costs and maximum obtainable functionality of the system. It is usually impossible to make great structural and interior changes for houses and therefore the geometrical shape and the configuration of inlets and outlets is almost definitely a given and non-changeable condition. The paper presents the CFD solution of miscellaneously improved cases for the various flow and shape configurations of the broiler house. Effects of the transversal and longitudinal ventilation are combined with the changes of inlet air streams directions and also with the different cross-section shaping obtained using curtains. All cases are evaluated and compared according to the same methodology. Results are discussed in terms of an existing state and also in terms of the expected costs needed for the ventilation system reconstruction.

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60-67 M. Hautala
Measurement and Modelling of Circumstances in Animal Houses: What, Why and How
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Measurement and Modelling of Circumstances in Animal Houses: What, Why and How

M. Hautala

Department of Agricultural Sciences, University of Helsinki, Finland
e-mail: mikko.hautala@helsinki.fi

Abstract:

The indoor air of the animal house has to be of such quality that the animal, the human being and the building should feel well. It means suitable temperature without moisture and gas, microbe and dust contents which should be low enough. The objective of our studies is to create general physical-chemical models for the ventilation and temperature of animal houses as the function of factors which affect micro climate (temperature, moisture, gases, dust, microbes, mould) and the heat balance of the animals. The optimal climate given by the models is achieved by the right ventilation. A system which is automatic or gives alarms and can be used to carry out the optimum conditions of the animal buildings in as stable a way as possible is needed. For this purpose reasonable and reliable sensors which measure the right factors are needed. So the results of sensors can be used for model based control of the ventilation in which case one can switch to the modelling adjustment in which more quantities can be simultaneously used and in such a way the quality of the indoor air of animal houses can be improved by the adjustment of only one quantity (temperature or moisture or carbon dioxide or other gas).

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255-262 A. Ruus, V. Poikalainen, J. Praks, I. Veermäe, F. Teye, M. Hautala and J. Ahokas
Indoor Air Temperature and Ventilation in Uninsulated Loose Housing Cowsheds with Different Types of Non-transparent Roofing in Hot Summer
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Indoor Air Temperature and Ventilation in Uninsulated Loose Housing Cowsheds with Different Types of Non-transparent Roofing in Hot Summer

A. Ruus¹, V. Poikalainen², J. Praks², I. Veermäe², F. Teye³, M. Hautala⁴ and J. Ahokas⁴

¹ Tartu College, Tallinn University of Technology,
78 Puiestee Srt., EE51008 Tartu, Estonia, e-mail: aime.ruus@ttu.ee
² Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life
Sciences, 62 Kreutzwaldi Str., EE51014 Tartu, Estonia; e-mail: vaino.poikalainen@emu.ee
³ Plant Production Research, MTT Agrifood Research Finland
MTT, Vakolantie 55, FIN03400, Vihti, Finland; e-mail: kwame@mappi.helsinki.fi
⁴ Department of Agrotechnology, University of Helsinki,
Koetilantie 3, FIN00014 Helsinki, Finland; e-mail: Jukka.Ahokas@helsinki.fi

Abstract:

As the indoor temperature of uninsulated cowsheds is in correlation with outdoor temperature, it may happen that indoor temperatures in cowsheds soar in hot summer. Roof temperature and spatial distribution of indoor air temperature at 1m (cow level) was studied in 8 uninsulated cowsheds with three different types of roof – non-asbestos cement sheets (4 cowsheds), metal (2 cowsheds) and insulated with 25 mm mineral wool plate (2 cowsheds) at outdoor air temperatures 26.8…32.0°C in at least 25 points of the cowshed. All openings were open in the cowsheds.
Roof (indoor surface) temperature values of 47.1°C were recorded as highest at non-asbestos cement roof in outdoor air temperature of 30°C. The average indoor surface temperature of the insulated roof (28°C) was about as high as outdoor air temperature (29°C).
Average indoor temperature in cowsheds varied 27.6-29.7°C. Smallest indoor-outdoor air temperature difference (t) was 0.8°C and occurred at lowest outdoor temperature (26.8°C). The biggest t of -2.3°C occurred at highest outdoor temperature (32°C). If the roof was insulated, t varied -0.5-1.1°C. In four cowsheds with non-asbestos cement sheet roof, t of 0.8…-1.9°C was recorded. In cowsheds with metal sheet roof, t of – 1.2… -2.3°C was recorded.
Standard deviation of indoor temperatures at the measurement points s (describes the ventilation efficiency) was s=0.59…0.84 in the cowsheds with insulated roof and s=0.46…0.66 in the uninsulated ones. The ventilation in cowsheds was good and air moving schemes uniform.
As a result of the investigation, the following conclusion can be made: indoor air temperature and ventilation efficiency in hot summer days are not influenced by roof material (non-transparent) or the presence of insulation.

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