The present paper is aimed at reviewing sustainable development and sustainability approach for infrastructure projects in the United Kingdom. It is imperative that major infrastructure projects (MIPs) adhere to the p...The present paper is aimed at reviewing sustainable development and sustainability approach for infrastructure projects in the United Kingdom. It is imperative that major infrastructure projects (MIPs) adhere to the principles of sustainable development in order to promote sustainability. This requires identifying sustainable strategies that are capable of serving as a guide to inculcating sustainability into major infrastructural projects. The current paper examines ways of inculcating sustainability into infrastructure projects bearing in mind that construction, maintenance and the way we use facilities have significant impacts on the environment. In addition to the fact that, decision making tools on methods of inculcating sustainability into infrastructure project appear too complex to stakeholders;and in most cases they do not provide stakeholders the necessary information required to make a good judgement. Hence, the present paper relies on desk study to gather existing data on infrastructure project and sustainable development. Existing data are obtained from books, scholarly articles and the WebPages of municipal authorities in the UK. Amongst other findings, the paper reveals that the utilization of environmental impact statements and environmental assessment documents at the formative stage of projects will aid the assessment of the level of sustainability to be achieved in any infrastructure development.展开更多
The demand for high-performance,yet eco-friendly materials is increasing on all scales from small applications in the car industry,instrument or furniture manufacturing to greater dimensions like floorings,balcony fur...The demand for high-performance,yet eco-friendly materials is increasing on all scales from small applications in the car industry,instrument or furniture manufacturing to greater dimensions like floorings,balcony furnishings and even construction.Wood offers a good choice on all of these scales and can be modified and improved in many different ways.In this study,two common European hardwood species,Beech(Fagus sylvatica L.)and Ash(Fraxinus excelsior L.)were densified in radial direction by thermo-mechanical treatment and the densified product was investigated in an extensive characterisation series to determine all relevant mechanical properties.Compression in the three main directions(longitudinal,tangential,radial)and tension perpendicular to the grain(tangential,radial)were tested and compared to reference specimens with native density.Strength and modulus of elasticity were determined in all tests.In addition,a Life Cycle Assessment was carried out to evaluate the environmental impact associated to the densification process.The experimental investigations showed that strength and stiffness of hardwood in the longitudinal and tangential directions improve significantly by radial densification,whereas some properties in the radial direction decrease.The Life Cycle Assessment showed that artificial wood drying has higher impact than wood densification.Furthermore,the transport distance of the raw material highly influences the environmental impact of the final densified product.The paper then also offers an overview of possible applications in structural timber construction.Densified hardwood is a viable option as local reinforcement,where high compressive or tensile strength is needed.The wood densification process offers an alternative to the use of carbon-intense steel components or hardwoods from tropical forests.展开更多
The present research is aimed to measure the porosity of anodes in solid oxide fuel cell through water Archimedeans method. There are various alternatives available to replace fossil fuel cells like nuclear power, win...The present research is aimed to measure the porosity of anodes in solid oxide fuel cell through water Archimedeans method. There are various alternatives available to replace fossil fuel cells like nuclear power, wind energy, solar energy, bio fuel, and geothermal and fuel cells. Among all the alternatives of fossil fuel, one form of energy production that stands out from the rest and promises a sustainable future energy is fuel cell. Moreover, it offers many advantages in contrast to other forms of energy generation. An Archimedean approach for water immersion porosimetry is carried out. Some of the results are beyond rational limits, and given negative and sometime above 100 percent porosity. The reasons for these unacceptable results are either due to water ingress into the sample or the sample turns into buoyant due to air in the cling film. The results from Archimedean porosimetry should only be used qualitatively due to errors associated with the results. It is also noted that Archimedean porosimetry is not the ideal technique for measuring the porosity of coated samples. It is suggested that larger samples should be analyzed that will help to minimize the weighing errors.展开更多
In order to obtain the suitable phase change material(PCM) with low phase change temperature and improve its heat transfer rate, experimental investigation was conducted. Firstly, different mass ratios of lauric aci...In order to obtain the suitable phase change material(PCM) with low phase change temperature and improve its heat transfer rate, experimental investigation was conducted. Firstly, different mass ratios of lauric acid(LA) and stearic acid(SA) eutectic mixtures were prepared and characterized by differential scanning calorimetry(DSC). Then, the performance of eutectic mixture during charging process under different fin widths in vertical condition, and performance during charging and discharging processes under different inlet temperature heat transfer fluid(HTF) in horizontal condition were investigated, respectively. The results revealed that the LA-SA eutectic mixture had the suitable phase change temperature and desired latent heat for low-temperature water floor heating system. Wide fins and high inlet temperature HTF significantly enhanced the transfer rate and decreased the melting time.展开更多
Energy efficiency is providing the same services consuming less energy.Less energy means less energy bill and less greenhouse emissions.Bhutan presents a unique scenario in promoting the use of energy efficiency equip...Energy efficiency is providing the same services consuming less energy.Less energy means less energy bill and less greenhouse emissions.Bhutan presents a unique scenario in promoting the use of energy efficiency equipment and investments.Bhutan enjoys availability of adequate low cost hydropower energy resource that is green and clean and enjoys cheap electrical energy.To aggravate the situation,the domestic tariffs are subsidized and even free up to 100 units in rural parts of the country.Export tariffs are determined independently according to entirely different principles.However for cooking,Bhutan imports LPG(Liquefied Petroleum Gas)from India.With increasing threats of climate change,it is reported water flow in rivers is decreasing.For energy security and related socio environmental issues,prospects of energy supply constraints and increasing demand of quality power in the country,there is a need to take appropriate policy measures which would lead to the development of indigenous,local and dispersed clean energy sources in the future.When a customer is asked to retrofit the house with energy efficiency,the owner questions oneself if the available investment resources are being directed to an effective return.Various criteria are available but all can not to be considered to come to a final decision.This paper presents an overview of many factors which affect energy efficiency investment in building in Bhutan.展开更多
Sentry buildings have windows that are often open to facilitate communication between personnel.It also provides the possibility for the intrusion of pollutants such as vehicle exhaust emissions.To prevent the intrusi...Sentry buildings have windows that are often open to facilitate communication between personnel.It also provides the possibility for the intrusion of pollutants such as vehicle exhaust emissions.To prevent the intrusion of outdoor pollutants and create an excellent indoor environment,internal circulation with double-attached ventilation(IC-DAV)and external circulation with double-attached ventilation(EC-DAV)are proposed for such buildings,and the isolation effect of two attached ventilation modes on pollutants is compared with that of natural ventilation.A computational fluid dynamics(CFD)method was used to simulate the transportation process and indoor distribution of outdoor pollutants intruding into sentry buildings from the regular openings under different outdoor wind directions,wind velocities,and states of the doors and ventilation modes.The results indicate that the leeward airflow of the three wind directions caused the largest pollutants to invade the room.The amount of pollutants intrusion increased with increasing wind velocity.When the leeward airflow and the windward airflow blow through the building,opening the door increased the amount of pollutants intruding into the room by 3.34 times and 8.85 times,respectively,compared with closing the door.However,the IC-DAV can isolate 81.7% of the pollutants while the EC-DAV can isolate 99.92% of the pollutants as compared with natural ventilation.Applying double attached ventilation mode in buildings can effectively prevent the intrusion of outdoor pollutants into the room,reduce the harm of outdoor pollutants to the health of indoor personnel,and provide a new idea for buildings to improve the indoor air quality.展开更多
This study aims to improve the accuracy and speed of predictions for thermal comfort and air quality in built environments by creating a coupled framework between computational fluid dynamics(CFD)simulations and deep ...This study aims to improve the accuracy and speed of predictions for thermal comfort and air quality in built environments by creating a coupled framework between computational fluid dynamics(CFD)simulations and deep learning models.The coupling approach is showcased by the development of a data-driven turbulence model.The new turbulence model is built using a deep learning neural network,whose mapping structure is based on a zero-equation turbulence model for built environment simulations,and is coupled with the CFD software OpenFOAM to create a hybrid framework.The neural network is a standard shallow multi-layer perceptron.The number of hidden layers and nodes per layer was optimized using Bayesan optimization algorithm.The framework is trained on an indoor environment case study,as well as tested on an indoor office simulation and an outdoor building array simulation.Results show that the deep learning based turbulence model is more robust and faster than traditional two-equation Reynolds average Navier-Stokes(RANS)turbulence models,while maintaining a similar level of accuracy.The model also outperforms the standard algebraic zero-equation model due to its superior ability to generalize to various flow scenarios.Despite some challenges,namely the mapping constraint,the limited training dataset size and the source of generation of training data,the hybrid framework demonstrates the viability of the coupling technique and serves as a starting point for future development of more reliable and advanced models.展开更多
Vernacular buildings are known for their localized passive settings to provide comfortable indoor environment without air conditioning systems.One alternative is the consistent ground temperature over the year that ea...Vernacular buildings are known for their localized passive settings to provide comfortable indoor environment without air conditioning systems.One alternative is the consistent ground temperature over the year that earth-sheltered envelopes take the benefit;however,ensuring annual indoor comfort might be challenging.Thus,this research monitors the indoor thermal indicators of 22 earth-sheltered buildings in Meymand,Iran with a warmdry climate.Furthermore,the observations are used to validate the simulation results through two outdoor and indoor environmental parameters,air temperature and relative humidity during the hottest period of the year.Findings indicated that the main thermal comfort differences among case studies were mainly due to their architectural layouts where the associated variables including length,width,height,orientation,window-to-wall ratio,and shading depth were optimized through a linkage between Ladybug-tools and Genetic Algorithm(GA)concerning adaptive thermal comfort model definition and could enhance the annual thermal comfort by 31%.展开更多
To achieve carbon targets,the European Union(EU)aims to promote nearly zero-energy buildings(nZEB).To enable the necessary transition,technical solutions need to converge with socio-economic factors,such values and aw...To achieve carbon targets,the European Union(EU)aims to promote nearly zero-energy buildings(nZEB).To enable the necessary transition,technical solutions need to converge with socio-economic factors,such values and awareness of stakeholders involved in the decision-making process.In this light,the aim of this paper is to characterise perceived drivers and barriers to nine energy-efficient technologies(EET),according to key decision-makers’and persuaders of the technology selection in the EU residential building context.Results are collected across eight EU countries,i.e.Belgium(BE),Germany(DE),Spain(ES),France(FR),Italy(IT),Netherlands(NL),Poland(PL),and United Kingdom(UK).The stakeholders’selected are architects,construction companies,engineers,installers and demand-side actors.Data from a multi-country survey is analysed to calculate the share of 15 drivers and 21 barriers(aggregated to 5 groups),being selected for each EET and country.The 5 groups considered to analyse drivers and barriers are environmental,technical,economic,social,legal.The perceived barriers and drivers were further studied for their association across the countries using the Pearson’s Chi2 and a Cramer’s V tests.The results demonstrate that across all EETs and countries,the technical and economic driver groups are perceived to have the highest potential to increase the implementation rate of EET.In terms of barriers,economic aspects are seen as the foremost reason that EET are not scaling faster.In both drivers and barriers legal aspects are the least often selected.In overall the barrier groups show significant variation across countries compared to driver groups.These findings provide an evidence-basis to better understand arguments in favour and against specific EETs and,in this way,support policy makers and other interested parties to increase the market share of the selected solutions.展开更多
Lavatories are frequently used facilities,especially on long-haul flights.Flushing a vacuum toilet in a lavatory can induce strong airflow,produce aerosols in the toilet bowl,and resuspend deposited particles from the...Lavatories are frequently used facilities,especially on long-haul flights.Flushing a vacuum toilet in a lavatory can induce strong airflow,produce aerosols in the toilet bowl,and resuspend deposited particles from the floor.However,the exact particle transport routes and the fates of particle after toilet flushing are unclear so far.This investigation used computational fluid dynamics(CFD)to model the transient airflow and pollutant transport after a toilet flushing process in a lavatory of a commercial aircraft.The time-varying pressure profile measured in a laboratory was assigned to the drainage valve as boundary conditions.The aerosols generated inside the toilet bowl during flushing and the particles resuspended from the lavatory floor were used as particle sources.Lagrangian tracking of airborne particles in the lavatory was conducted.In addition,ammonia gas was used to examine odor perception.The multi-physics software program COMSOL 5.4 was employed for numerical solution after being validated.The results revealed that more than 70%of the generated particles in the toilet bowl are drained into sewage.A few particles may leak out of the toilet bowl and remain suspended in the air for more than five minutes when the toilet lid is open during flushing.Flushing the toilet with a closed lid can effectively reduce the particle leakage and the spread of odor gas,but it leads to greater deposition of particles on both the lid and seat.There is a slight inhalation exposure risk in the initial three minutes after flushing with a closed lid.展开更多
High-concentration oil mists can cause serious health problems to workers,which are generally mitigated by ventilation and purification systems.However,the coupling relationship between these systems is not clear.In t...High-concentration oil mists can cause serious health problems to workers,which are generally mitigated by ventilation and purification systems.However,the coupling relationship between these systems is not clear.In this study,the effects of purifier outlet direction,purification air volume,installation height,and purification efficiency on indoor oil mist distribution were investigated by numerical simulation using an actual machining factory.The mitigation of oil mist in various combinations of ventilation and purification systems was also discussed.The results show that the outlet direction of the purifier has a great influence on the distribution of oil mist in the factory,and the maximum difference of oil mist concentration in the breathing zone under different orientations is 17%.The best purifier outlet direction is vertically upward.When the purifier outlet direction is upward,a larger purification air volume is beneficial for contaminant removal,and a lower purifier exhaust installation height is helpful for oil mist discharge from the bottom of the factory and reducing the concentration of oil mist in the breathing area.The oil mist concentration of purifier exhaust increases from 0 to 2 mg/m^(3) and the oil mist concentration in the breathing zone increases by 67%.The combined system of purification system with the roof exhaust system and displacement ventilation system has the optimal pollution removal efficiency and the lowest concentration of oil mist in the breathing zone compared to other systems.The research results can provide a reference for the design,installation,and operation of ventilation and purification systems in machining factories.展开更多
Natural ventilation(NV)has been considered a simple and effective method of ventilation.However,the intro-duction of NV does not achieve better indoor air quality(IAQ)when the outdoor atmospheric environment is pollut...Natural ventilation(NV)has been considered a simple and effective method of ventilation.However,the intro-duction of NV does not achieve better indoor air quality(IAQ)when the outdoor atmospheric environment is polluted.Therefore,portable air cleaners(PACs)are increasing in use in recent years,but their effectiveness is highly dependent on the residents’habits.A typical residence in Xi’an,China was selected to examine the effects of the use of NV alone and the use of NV and PACs together on IAQ in the three occupant states,i.e.,unoc-cupied,sleeping and leisure.Parameters,such as temperature,relative humidity,CO_(2),and PM_(2.5)concentration were measured when changing the window opening and the position of the PAC.The results showed that in the unoccupied state,opening the inner door can promote a more uniform thermal and humid environment.In the sleeping state,the I/O ratio of the PM_(2.5)concentration was the lowest when the window opening of the bedroom was 1/2 or 3/4,with a mean value of 0.3.In the leisure state,only using NV,when the purification rate reaches 90%,the mean purification time of each window opening in the living room is 87.5 min.The mean purification time was reduced to 25 min when both NV and PAC were used.The on-site purification efficiencies were 91.0%and 94.5%,when the window opening was 1/2(i.e.,the PAC was placed in the center of the room)and 3/4(i.e.,the PAC was placed away from the outer window),respectively.展开更多
Changing climate intensifies heat stress,resulting in a greater risk of workplace productivity decline in timber office buildings with low internal thermal mass.The impact of climate change induced heat exposure on in...Changing climate intensifies heat stress,resulting in a greater risk of workplace productivity decline in timber office buildings with low internal thermal mass.The impact of climate change induced heat exposure on indoor workplace productivity in timber office buildings has not been extensively researched.Therefore,further investigation to reduce the work capacity decline towards the end of the century is needed.Here,heat exposure in a net zero-carbon timber building near Brussels,Belgium,was evaluated using a reproducible comparative approach with different internal thermal mass levels.The analysis indicated that strategies with increased thermal mass were more effective in limiting the effects of heat exposure on workplace productivity.The medium and high thermal mass strategies reduced workplace productivity loss to 0.1%in the current,0.3%and 0.2%in the midfuture,and 4.9%and 3.9%for future scenarios.In comparison,baseline with low thermal mass yielded a decline of 2.3%,3.3%,and 8.2%.The variation in maximum and minimum wet-bulb globe temperatures were also lower for medium and high thermal mass strategies than for low thermal mass baseline.The study findings lead to the formulation of design guidelines,identification of research gaps,and recommendations for future work.展开更多
文摘The present paper is aimed at reviewing sustainable development and sustainability approach for infrastructure projects in the United Kingdom. It is imperative that major infrastructure projects (MIPs) adhere to the principles of sustainable development in order to promote sustainability. This requires identifying sustainable strategies that are capable of serving as a guide to inculcating sustainability into major infrastructural projects. The current paper examines ways of inculcating sustainability into infrastructure projects bearing in mind that construction, maintenance and the way we use facilities have significant impacts on the environment. In addition to the fact that, decision making tools on methods of inculcating sustainability into infrastructure project appear too complex to stakeholders;and in most cases they do not provide stakeholders the necessary information required to make a good judgement. Hence, the present paper relies on desk study to gather existing data on infrastructure project and sustainable development. Existing data are obtained from books, scholarly articles and the WebPages of municipal authorities in the UK. Amongst other findings, the paper reveals that the utilization of environmental impact statements and environmental assessment documents at the formative stage of projects will aid the assessment of the level of sustainability to be achieved in any infrastructure development.
文摘The demand for high-performance,yet eco-friendly materials is increasing on all scales from small applications in the car industry,instrument or furniture manufacturing to greater dimensions like floorings,balcony furnishings and even construction.Wood offers a good choice on all of these scales and can be modified and improved in many different ways.In this study,two common European hardwood species,Beech(Fagus sylvatica L.)and Ash(Fraxinus excelsior L.)were densified in radial direction by thermo-mechanical treatment and the densified product was investigated in an extensive characterisation series to determine all relevant mechanical properties.Compression in the three main directions(longitudinal,tangential,radial)and tension perpendicular to the grain(tangential,radial)were tested and compared to reference specimens with native density.Strength and modulus of elasticity were determined in all tests.In addition,a Life Cycle Assessment was carried out to evaluate the environmental impact associated to the densification process.The experimental investigations showed that strength and stiffness of hardwood in the longitudinal and tangential directions improve significantly by radial densification,whereas some properties in the radial direction decrease.The Life Cycle Assessment showed that artificial wood drying has higher impact than wood densification.Furthermore,the transport distance of the raw material highly influences the environmental impact of the final densified product.The paper then also offers an overview of possible applications in structural timber construction.Densified hardwood is a viable option as local reinforcement,where high compressive or tensile strength is needed.The wood densification process offers an alternative to the use of carbon-intense steel components or hardwoods from tropical forests.
文摘The present research is aimed to measure the porosity of anodes in solid oxide fuel cell through water Archimedeans method. There are various alternatives available to replace fossil fuel cells like nuclear power, wind energy, solar energy, bio fuel, and geothermal and fuel cells. Among all the alternatives of fossil fuel, one form of energy production that stands out from the rest and promises a sustainable future energy is fuel cell. Moreover, it offers many advantages in contrast to other forms of energy generation. An Archimedean approach for water immersion porosimetry is carried out. Some of the results are beyond rational limits, and given negative and sometime above 100 percent porosity. The reasons for these unacceptable results are either due to water ingress into the sample or the sample turns into buoyant due to air in the cling film. The results from Archimedean porosimetry should only be used qualitatively due to errors associated with the results. It is also noted that Archimedean porosimetry is not the ideal technique for measuring the porosity of coated samples. It is suggested that larger samples should be analyzed that will help to minimize the weighing errors.
基金Funded by the Key Project of National Natural Science Foundation of China(No.51432007)the National Key Research and Development Program of China(No.2016 YFC0700201)+1 种基金the Science,Technology Support Program of Hubei Province(Nos.2014BAA134 and 2015BAA107)the Postdoctoral Fund of China(2017M612629)
文摘In order to obtain the suitable phase change material(PCM) with low phase change temperature and improve its heat transfer rate, experimental investigation was conducted. Firstly, different mass ratios of lauric acid(LA) and stearic acid(SA) eutectic mixtures were prepared and characterized by differential scanning calorimetry(DSC). Then, the performance of eutectic mixture during charging process under different fin widths in vertical condition, and performance during charging and discharging processes under different inlet temperature heat transfer fluid(HTF) in horizontal condition were investigated, respectively. The results revealed that the LA-SA eutectic mixture had the suitable phase change temperature and desired latent heat for low-temperature water floor heating system. Wide fins and high inlet temperature HTF significantly enhanced the transfer rate and decreased the melting time.
文摘Energy efficiency is providing the same services consuming less energy.Less energy means less energy bill and less greenhouse emissions.Bhutan presents a unique scenario in promoting the use of energy efficiency equipment and investments.Bhutan enjoys availability of adequate low cost hydropower energy resource that is green and clean and enjoys cheap electrical energy.To aggravate the situation,the domestic tariffs are subsidized and even free up to 100 units in rural parts of the country.Export tariffs are determined independently according to entirely different principles.However for cooking,Bhutan imports LPG(Liquefied Petroleum Gas)from India.With increasing threats of climate change,it is reported water flow in rivers is decreasing.For energy security and related socio environmental issues,prospects of energy supply constraints and increasing demand of quality power in the country,there is a need to take appropriate policy measures which would lead to the development of indigenous,local and dispersed clean energy sources in the future.When a customer is asked to retrofit the house with energy efficiency,the owner questions oneself if the available investment resources are being directed to an effective return.Various criteria are available but all can not to be considered to come to a final decision.This paper presents an overview of many factors which affect energy efficiency investment in building in Bhutan.
基金jointly funded by the National Key Research and Development Program of China(No.2016YFC0700500)the Natural Science Foundation of Shaanxi Province(No.2021JM-361)the Opening Fund of Qinghai Provincial Key Laboratory of Plateau Green Building and Eco-community(No.KLKF-2020-005).
文摘Sentry buildings have windows that are often open to facilitate communication between personnel.It also provides the possibility for the intrusion of pollutants such as vehicle exhaust emissions.To prevent the intrusion of outdoor pollutants and create an excellent indoor environment,internal circulation with double-attached ventilation(IC-DAV)and external circulation with double-attached ventilation(EC-DAV)are proposed for such buildings,and the isolation effect of two attached ventilation modes on pollutants is compared with that of natural ventilation.A computational fluid dynamics(CFD)method was used to simulate the transportation process and indoor distribution of outdoor pollutants intruding into sentry buildings from the regular openings under different outdoor wind directions,wind velocities,and states of the doors and ventilation modes.The results indicate that the leeward airflow of the three wind directions caused the largest pollutants to invade the room.The amount of pollutants intrusion increased with increasing wind velocity.When the leeward airflow and the windward airflow blow through the building,opening the door increased the amount of pollutants intruding into the room by 3.34 times and 8.85 times,respectively,compared with closing the door.However,the IC-DAV can isolate 81.7% of the pollutants while the EC-DAV can isolate 99.92% of the pollutants as compared with natural ventilation.Applying double attached ventilation mode in buildings can effectively prevent the intrusion of outdoor pollutants into the room,reduce the harm of outdoor pollutants to the health of indoor personnel,and provide a new idea for buildings to improve the indoor air quality.
基金This work was supported by the Digital Futures and C3.ai Digital Transformation Institute project.
文摘This study aims to improve the accuracy and speed of predictions for thermal comfort and air quality in built environments by creating a coupled framework between computational fluid dynamics(CFD)simulations and deep learning models.The coupling approach is showcased by the development of a data-driven turbulence model.The new turbulence model is built using a deep learning neural network,whose mapping structure is based on a zero-equation turbulence model for built environment simulations,and is coupled with the CFD software OpenFOAM to create a hybrid framework.The neural network is a standard shallow multi-layer perceptron.The number of hidden layers and nodes per layer was optimized using Bayesan optimization algorithm.The framework is trained on an indoor environment case study,as well as tested on an indoor office simulation and an outdoor building array simulation.Results show that the deep learning based turbulence model is more robust and faster than traditional two-equation Reynolds average Navier-Stokes(RANS)turbulence models,while maintaining a similar level of accuracy.The model also outperforms the standard algebraic zero-equation model due to its superior ability to generalize to various flow scenarios.Despite some challenges,namely the mapping constraint,the limited training dataset size and the source of generation of training data,the hybrid framework demonstrates the viability of the coupling technique and serves as a starting point for future development of more reliable and advanced models.
文摘Vernacular buildings are known for their localized passive settings to provide comfortable indoor environment without air conditioning systems.One alternative is the consistent ground temperature over the year that earth-sheltered envelopes take the benefit;however,ensuring annual indoor comfort might be challenging.Thus,this research monitors the indoor thermal indicators of 22 earth-sheltered buildings in Meymand,Iran with a warmdry climate.Furthermore,the observations are used to validate the simulation results through two outdoor and indoor environmental parameters,air temperature and relative humidity during the hottest period of the year.Findings indicated that the main thermal comfort differences among case studies were mainly due to their architectural layouts where the associated variables including length,width,height,orientation,window-to-wall ratio,and shading depth were optimized through a linkage between Ladybug-tools and Genetic Algorithm(GA)concerning adaptive thermal comfort model definition and could enhance the annual thermal comfort by 31%.
基金This work has been financed by Climate-KIC,supported by the EIT-a body of the European Union TC_2.7.8_190515_P183-1B under the h2020 framework.
文摘To achieve carbon targets,the European Union(EU)aims to promote nearly zero-energy buildings(nZEB).To enable the necessary transition,technical solutions need to converge with socio-economic factors,such values and awareness of stakeholders involved in the decision-making process.In this light,the aim of this paper is to characterise perceived drivers and barriers to nine energy-efficient technologies(EET),according to key decision-makers’and persuaders of the technology selection in the EU residential building context.Results are collected across eight EU countries,i.e.Belgium(BE),Germany(DE),Spain(ES),France(FR),Italy(IT),Netherlands(NL),Poland(PL),and United Kingdom(UK).The stakeholders’selected are architects,construction companies,engineers,installers and demand-side actors.Data from a multi-country survey is analysed to calculate the share of 15 drivers and 21 barriers(aggregated to 5 groups),being selected for each EET and country.The 5 groups considered to analyse drivers and barriers are environmental,technical,economic,social,legal.The perceived barriers and drivers were further studied for their association across the countries using the Pearson’s Chi2 and a Cramer’s V tests.The results demonstrate that across all EETs and countries,the technical and economic driver groups are perceived to have the highest potential to increase the implementation rate of EET.In terms of barriers,economic aspects are seen as the foremost reason that EET are not scaling faster.In both drivers and barriers legal aspects are the least often selected.In overall the barrier groups show significant variation across countries compared to driver groups.These findings provide an evidence-basis to better understand arguments in favour and against specific EETs and,in this way,support policy makers and other interested parties to increase the market share of the selected solutions.
基金supported by the National Natural Science Foundation of China (Grant No.52111530186)Stiftelsen for internationalisering av hogre utbildning och forskning (STINT),Sweden (Dnr:CH2020-8665).
文摘Lavatories are frequently used facilities,especially on long-haul flights.Flushing a vacuum toilet in a lavatory can induce strong airflow,produce aerosols in the toilet bowl,and resuspend deposited particles from the floor.However,the exact particle transport routes and the fates of particle after toilet flushing are unclear so far.This investigation used computational fluid dynamics(CFD)to model the transient airflow and pollutant transport after a toilet flushing process in a lavatory of a commercial aircraft.The time-varying pressure profile measured in a laboratory was assigned to the drainage valve as boundary conditions.The aerosols generated inside the toilet bowl during flushing and the particles resuspended from the lavatory floor were used as particle sources.Lagrangian tracking of airborne particles in the lavatory was conducted.In addition,ammonia gas was used to examine odor perception.The multi-physics software program COMSOL 5.4 was employed for numerical solution after being validated.The results revealed that more than 70%of the generated particles in the toilet bowl are drained into sewage.A few particles may leak out of the toilet bowl and remain suspended in the air for more than five minutes when the toilet lid is open during flushing.Flushing the toilet with a closed lid can effectively reduce the particle leakage and the spread of odor gas,but it leads to greater deposition of particles on both the lid and seat.There is a slight inhalation exposure risk in the initial three minutes after flushing with a closed lid.
基金supported by the National Nature Science Foundation of China (No.51878442).
文摘High-concentration oil mists can cause serious health problems to workers,which are generally mitigated by ventilation and purification systems.However,the coupling relationship between these systems is not clear.In this study,the effects of purifier outlet direction,purification air volume,installation height,and purification efficiency on indoor oil mist distribution were investigated by numerical simulation using an actual machining factory.The mitigation of oil mist in various combinations of ventilation and purification systems was also discussed.The results show that the outlet direction of the purifier has a great influence on the distribution of oil mist in the factory,and the maximum difference of oil mist concentration in the breathing zone under different orientations is 17%.The best purifier outlet direction is vertically upward.When the purifier outlet direction is upward,a larger purification air volume is beneficial for contaminant removal,and a lower purifier exhaust installation height is helpful for oil mist discharge from the bottom of the factory and reducing the concentration of oil mist in the breathing area.The oil mist concentration of purifier exhaust increases from 0 to 2 mg/m^(3) and the oil mist concentration in the breathing zone increases by 67%.The combined system of purification system with the roof exhaust system and displacement ventilation system has the optimal pollution removal efficiency and the lowest concentration of oil mist in the breathing zone compared to other systems.The research results can provide a reference for the design,installation,and operation of ventilation and purification systems in machining factories.
基金This study was jointly funded by the National Key Research and Development Program of China(No.2016YFC0700500)the Opening Fund of Key Laboratory of Plateau Green Building and Ecological Community in Qinghai Province(No.KLKF-2020-005).
文摘Natural ventilation(NV)has been considered a simple and effective method of ventilation.However,the intro-duction of NV does not achieve better indoor air quality(IAQ)when the outdoor atmospheric environment is polluted.Therefore,portable air cleaners(PACs)are increasing in use in recent years,but their effectiveness is highly dependent on the residents’habits.A typical residence in Xi’an,China was selected to examine the effects of the use of NV alone and the use of NV and PACs together on IAQ in the three occupant states,i.e.,unoc-cupied,sleeping and leisure.Parameters,such as temperature,relative humidity,CO_(2),and PM_(2.5)concentration were measured when changing the window opening and the position of the PAC.The results showed that in the unoccupied state,opening the inner door can promote a more uniform thermal and humid environment.In the sleeping state,the I/O ratio of the PM_(2.5)concentration was the lowest when the window opening of the bedroom was 1/2 or 3/4,with a mean value of 0.3.In the leisure state,only using NV,when the purification rate reaches 90%,the mean purification time of each window opening in the living room is 87.5 min.The mean purification time was reduced to 25 min when both NV and PAC were used.The on-site purification efficiencies were 91.0%and 94.5%,when the window opening was 1/2(i.e.,the PAC was placed in the center of the room)and 3/4(i.e.,the PAC was placed away from the outer window),respectively.
基金the Service Public de Wallonie(SPW),Belgium,under BElgian WAllonia REsearch(BEWARE)fellowships and European Union(EU)framework program for research and innovation,Marie Skłodowska-Curie Actions(MSCA)through contract no.847587 for the Project SurChauffe.the U.S.Department of Energy,Office of Science,Office of Biological and Environmental Research’s Urban Integrated Field Laboratories research activity,under Award Number DE-SC0023520.+2 种基金the members of the School of Geographical Sciences and Urban Planning at Arizona State University,and Southwest Urban Corridor Integrated Field Laboratory(SW-IFL)for their support.We would also like to thank the stakeholders of Project OCCuPANt.the Sustainable Building Design Lab at the Faculty of Applied Sciences at the University of Liege for the valuable support and use of the state-of-the-art Super COmputeR ProcessIng wOrkstatioN(SCORPION)for building performance simulations and data analysis.the IEA EBC Annex 80-Resilient Cooling of Buildings.
文摘Changing climate intensifies heat stress,resulting in a greater risk of workplace productivity decline in timber office buildings with low internal thermal mass.The impact of climate change induced heat exposure on indoor workplace productivity in timber office buildings has not been extensively researched.Therefore,further investigation to reduce the work capacity decline towards the end of the century is needed.Here,heat exposure in a net zero-carbon timber building near Brussels,Belgium,was evaluated using a reproducible comparative approach with different internal thermal mass levels.The analysis indicated that strategies with increased thermal mass were more effective in limiting the effects of heat exposure on workplace productivity.The medium and high thermal mass strategies reduced workplace productivity loss to 0.1%in the current,0.3%and 0.2%in the midfuture,and 4.9%and 3.9%for future scenarios.In comparison,baseline with low thermal mass yielded a decline of 2.3%,3.3%,and 8.2%.The variation in maximum and minimum wet-bulb globe temperatures were also lower for medium and high thermal mass strategies than for low thermal mass baseline.The study findings lead to the formulation of design guidelines,identification of research gaps,and recommendations for future work.