Investigation into an alternative approach of environmental control to enhance sensible heat transfer from broiler chickens during hot weather periods

Climatic conditions within the broiler building play an important role in the performances, health and welfare of broiler chickens. During hot weather periods, farmers in the temperate climates usually open all inlets onthe sidewall andoperate all the fans in theroof of thebroiler building to allow maximum airflow to relieve broilers of heat stress. However, the effects of this practice on the air velocity distribution in the broiler occupied zones of such type of building are not well documented. Therefore, this research work was set up to (1) investigate the impact of wide opened inlet on the airflow characteristics in the broiler occupied zones of an experimental broiler building at Harper Adams University, UK; (2) develop and evaluate the performance of a hot weather ventilation system, incorporatingan oscillation baffle, for broiler buildings; (3) examine the impact of the ventilation system on the airflow characteristics in the broiler occupied zones and the sensible heat transfer from broiler model. The results of the study indicated that the act of fully opening the inlets of broiler building during hot weather seasons did not improve the airflow in the broiler occupied zones at all measurement locations, including the sidewall area of the building. However, with the development of the hot weatherventilation system with oscillation baffle, operating at different fanfrequencies, baffle oscillation angles and baffle oscillation frequencies, there was a significant improvement in the average air velocity in the broiler occupied zones. At higher inlet turbulence, there was an increase in the sensible heat transfer from broilersin the sidewall area of the broiler building. This indicates that oscillation of inlet baffle instead of keeping it wide opened during the hot weather periods could direct moreairflow into the broiler occupied zones and relieve broiler chickens of heat stress

Effect of Fans’ Placement on the Indoor Thermal Environment of Typical Tunnel-Ventilated Multi-Floor Pig Buildings Using Numerical Simulation

An increasing number of large pig farms are being built in multi-floor pig buildings (MFPBs) in China. Currently, the ventilation system of MFPB varies greatly and lacks common standards. This work aims to compare the ventilation performance of three popular MFPB types with different placement of fans using the Computational Fluid Dynamics (CFD) technique. After being validated with field-measured data, the CFD models were extended to simulate the air velocity, air temperature, humidity, and effective temperature of the three MFPBs. The simulation results showed that the ventilation rate of the building with outflowing openings in the endwall and fans installed on the top of the shaft was approximately 25% less than the two buildings with fans installed on each floor. The ventilation rate of each floor increased from the first to the top floor for both buildings with a shaft, while no significant difference was observed in the building without a shaft. Increasing the shaft’s width could mitigate the variation in the ventilation rate of each floor. The effective temperature distribution at the animal level was consistent with the air velocity distribution. Therefore, in terms of the indoor environmental condition, the fans were recommended to be installed separately on each floor

The impact of ventilation type on the heat load of dairy cows

Received: January 31st, 2021 ; Accepted: March 27th, 2021 ; Published: November 26th, 2021 ; Correspondence: [email protected] load in cattle causes deterioration of health and reduced production of milk. Therefore, it is necessary to protect cows by appropriate passive and active means and monitor the air quality in barns. Based on several indicators of environmental quality, is possible to make a more comprehensive assessment of the microclimate and more precise conclusions. This study, was monitoring the values of air temperature, relative humidity, and air velocity in two barns with the same volume and layout with floor dimensions of 26.6 m × 62.1 m. In barn 1, roof ridge of which had underwent only partial reconstruction, there were installed fourteen basket fans with a total fan performance Q(1)fans = 218,400 m3 h -1 . In barn 2, there were twelve panel fans with a total fan performance Q(2)fans = 289,320 m3 h -1 . The resulting THI, HLI and ETIC values were compared in relation to each other and in relation to the recommended values. Despite the operating ventilation technology and enlargement of wall openings, the above-limit values of climatic characteristics were observed in both barns during tropical days. There were no differences between the barns (p ˃ 0.05), in barn 1: THI(1) = 83.10 ± 0.51; HLI(1) = 85.62 ± 1.42; ETIC(1) = 27.24 ± 0.31, and in barn 2: THI(2) = 83.12 ± 0.34; HLI(2) = 85.77 ± 1.50; ETIC(2) = 27.29 ± 0.28, however, there were found significant differences in values of temperature indices obtained in the detailed measurements at points arranged perpendicularly, as well as parallelly, to the direction of air velocity in the animal zone (p < 0.05)

Housing Environment and Farm Animals' Well-Being

This reprint contains articles from the Special Issue of Animals “Housing Environment and Farm Animals' Well-Being”, including original research, review, and communication related to livestock and poultry environmental management, air quality control, emissions mitigation, and assessment of animal health and well-being

A review of solar hybrid photovoltaic-thermal (PV-T) collectors and systems

In this paper, we provide a comprehensive overview of the state-of-the-art in hybrid PV-T collectors and the wider systems within which they can be implemented, and assess the worldwide energy and carbon mitigation potential of these systems. We cover both experimental and computational studies, identify opportunities for performance enhancement, pathways for collector innovation, and implications of their wider deployment at the solar-generation system level. First, we classify and review the main types of PV-T collectors, including air-based, liquid-based, dual air–water, heat-pipe, building integrated and concentrated PV-T collectors. This is followed by a presentation of performance enhancement opportunities and pathways for collector innovation. Here, we address state-of-the-art design modifications, next-generation PV cell technologies, selective coatings, spectral splitting and nanofluids. Beyond this, we address wider PV-T systems and their applications, comprising a thorough review of solar combined heat and power (S–CHP), solar cooling, solar combined cooling, heat and power (S–CCHP), solar desalination, solar drying and solar for hydrogen production systems. This includes a specific review of potential performance and cost improvements and opportunities at the solar-generation system level in thermal energy storage, control and demand-side management. Subsequently, a set of the most promising PV-T systems is assessed to analyse their carbon mitigation potential and how this technology might fit within pathways for global decarbonization. It is estimated that the REmap baseline emission curve can be reduced by more than 16% in 2030 if the uptake of solar PV-T technologies can be promoted. Finally, the review turns to a critical examination of key challenges for the adoption of PV-T technology and recommendations

A Review of Solar Hybrid Photovoltaic-Thermal (PV-T) Collectors and Systems

In this paper, we provide a comprehensive overview of the state-of-the-art in hybrid PV-T collectors and the wider systems within which they can be implemented, and assess the worldwide energy and carbon mitigation potential of these systems. We cover both experimental and computational studies, identify opportunities for performance enhancement, pathways for collector innovation, and implications of their wider deployment at the solar-generation system level. First, we classify and review the main types of PV-T collectors, including air-based, liquid-based, dual air–water, heat-pipe, building integrated and concentrated PV-T collectors. This is followed by a presentation of performance enhancement opportunities and pathways for collector innovation. Here, we address state-of-the-art design modifications, next-generation PV cell technologies, selective coatings, spectral splitting and nanofluids. Beyond this, we address wider PV-T systems and their applications, comprising a thorough review of solar combined heat and power (S–CHP), solar cooling, solar combined cooling, heat and power (S–CCHP), solar desalination, solar drying and solar for hydrogen production systems. This includes a specific review of potential performance and cost improvements and opportunities at the solar-generation system level in thermal energy storage, control and demand-side management. Subsequently, a set of the most promising PV-T systems is assessed to analyse their carbon mitigation potential and how this technology might fit within pathways for global decarbonization. It is estimated that the REmap baseline emission curve can be reduced by more than 16% in 2030 if the uptake of solar PV-T technologies can be promoted. Finally, the review turns to a critical examination of key challenges for the adoption of PV-T technology and recommendations

Ventilation and thermal performance of an integrated system for use in heritage buildings.

Providing modern mechanical heat recovery ventilation for heritage dwellings poses the challenge of invasive duct-work and unwanted modifications to the building fabric. A retrofitted ventilation system will be more desirable if it is inconspicuous and hidden within the building fabric. The author’s original contribution to knowledge encompasses the original proposal and development from first principles of a novel natural ventilation heat recovery system utilizing disused chimneys in heritage dwellings. The system consists of an omnidirectional flue-like windcatcher integrated with a plate heat exchanger. This research provided new information on functional design of geometry, operational characteristics, and feasibility in terms of ventilation and heat recovery performance of counter-current natural air flow in the system. Two commercial CFD programs, namely Autodesk CFD 2013 and Ansys Fluent v14 were employed to perform RANS simulation of 3D models of the system. A comparison of flow results gotten from these packages showed a maximum difference of 10%. This proved the corresponding accuracy of the simpler and more user-friendly Autodesk CFD when compared with the more established Ansys Fluent software package. The air flow and thermal performance of the system’s two main parts were investigated at steady state wind speeds of 0.5m/s, 1.5m/s, 2.5m/s, 3.5m/s and 4.5m/s incident on the windcatcher at 90 degrees. Results were evaluated for a 27m³ design room ventilated at 0.7ach. At all wind speeds, the final windcatcher prototype exhibited the desired flow pattern with no short-circuit and provided more than the minimum required air change rate at all incident wind speeds above 1m⁄s. When the windcatcher is integrated with the heat exchanger, the system’s ventilation performance was 0.3ach at 0.5m/s incident wind speed. This increased to 4.5ach at 4.5m/s incident wind speed. Thermal effectiveness of the system peaked at 46% at 0.5m/s wind speed and decreased to 22% at 4.5m/s wind speed. When compared with the heat exchanger solitary performance, thermal effectiveness was reduced by an average of 27% at all incident wind speeds. This performance reduction is due to the non-uniform pattern of supply air flow through the system. Further work is required to provide experimental data on the performance of the system and investigate the effect of unsteady air flow incident at different angles on the windcatcher. Proposals for these are included. Further work is also required to incorporate features that will minimize fouling in operation and improve heat recovery effectiveness.PhD in Energy and Powe

CISBAT 2009: International Scientific Conference - Renewables in a changing climate - From Nano to Urban Scale

Centred on research and development in solar energy applications to the built environment, the international conference CISBAT 2009 highlighted a large number of interesting technological innovations. The discoveries and developments presented by scientists from five continents are all part of the effort to mitigate greenhouse gas emissions generated by buildings. Renewables are expected to play a very important role against the global threat of a changing climate, even more so as 2009 will hopefully see a new “Post-Kyoto” era in their favour to be initiated at the COP15 United National Climate Change Conference to be held in Copenhagen (Denmark).“Anti-crisis” programmes, which have been launched by several countries in favour of job creation within the framework of a “Green New Deal” will also contribute to sustain the solar momentum.The organisers of the CISBAT Conference, financially supported by the Swiss Federal Office of Energy (SFOE), therefore had no problem convincing their academic partners - Cambridge University (CU) and the Massachusetts Institute of Technology (MIT) - to collaborate in the organisation of this event on the EPFL campus. More than 200 participants from 30 different countries were present during the two conference days and we are confident that they will be even more numerous at the next edition, as feedback from attendees encourages the organisers to increase the size and the duration of the CISBAT conference

Rural structures in the tropics: Design and development

There is a growing awareness of the need for better rural structures and services in many developing countries. Here the FAO presents an up-to-date, comprehensive text focusing on structures for small- to medium-scale farms and, to some extent, village-scale agricultural infrastructure. The book will help to improve teaching on the subject of rural buildings in the tropics and will assist professionals engaged in providing technical advice. Importantly, it also provides guidance in the context of disaster recovery and rehabilitation, for rebuilding the sound rural structures and related services that are key to development and economic sustainability

A review of solar hybrid photovoltaic-thermal (PV-T) collectors and systems

In this paper, we provide a comprehensive overview of the state-of-the-art in hybrid PV-T collectors and the wider systems within which they can be implemented, and assess the worldwide energy and carbon mitigation potential of these systems. We cover both experimental and computational studies, identify opportunities for performance enhancement, pathways for collector innovation, and implications of their wider deployment at the solar-generation system level. First, we classify and review the main types of PV-T collectors, including air-based, liquid-based, dual air–water, heat-pipe, building integrated and concentrated PV-T collectors. This is followed by a presentation of performance enhancement opportunities and pathways for collector innovation. Here, we address state-of-the-art design modifications, next-generation PV cell technologies, selective coatings, spectral splitting and nanofluids. Beyond this, we address wider PV-T systems and their applications, comprising a thorough review of solar combined heat and power (S–CHP), solar cooling, solar combined cooling, heat and power (S–CCHP), solar desalination, solar drying and solar for hydrogen production systems. This includes a specific review of potential performance and cost improvements and opportunities at the solar-generation system level in thermal energy storage, control and demand-side management. Subsequently, a set of the most promising PV-T systems is assessed to analyse their carbon mitigation potential and how this technology might fit within pathways for global decarbonization. It is estimated that the REmap baseline emission curve can be reduced by more than 16% in 2030 if the uptake of solar PV-T technologies can be promoted. Finally, the review turns to a critical examination of key challenges for the adoption of PV-T technology and recommendations