Pub Date : 2021-06-11DOI: 10.1177/01436244211024084
T. Jayasree, B. S. Jinshah, Tadepalli Srinivas
Ceiling fans are the most common equipment in any household with electricity to induce a higher air movement since the potential of natural ventilation is limited. However, the higher airflow region is generally limited to the zone below the fan. The non-uniform distribution of airflow is also affected by the furniture layout and airflow from window openings. This study attempts to evaluate the effect of the different window-opening patterns on the airflow inside naturally ventilated bedrooms, having a ceiling fan for air movement with numerical simulations and on-site measurements. The airflow pattern created by a ceiling fan in a room with furniture is modelled and simulated with ANSYS Fluent 2019 R3. The results were validated with on-site measurements and compared with the literature. The air velocity was measured in bedrooms of three different sizes. It was observed that the opening of windows created a better distribution of air irrespective of room size. The non-uniformity of the air velocity is reduced from 76% to 39% with the opening of windows in the larger-sized room. The reduction in non-uniformity is influenced by the location of windows also. The practice of opening windows along with the induced air movement by ceiling fans results in a better distribution of air in the space. Practical application : People tend to depend mainly on ceiling fans even if windows are open in naturally ventilated rooms. A study of patterns of non-uniform distribution of airflow can help designers to improve comfort conditions by specifying the number and location of fans and windows while designing room furniture layout. This aids the building services engineers to provide thermal comfort without always depending on alternative active ventilation strategies.
{"title":"The effect of opening windows on the airflow distribution inside naturally ventilated residential bedrooms with ceiling fans","authors":"T. Jayasree, B. S. Jinshah, Tadepalli Srinivas","doi":"10.1177/01436244211024084","DOIUrl":"https://doi.org/10.1177/01436244211024084","url":null,"abstract":"Ceiling fans are the most common equipment in any household with electricity to induce a higher air movement since the potential of natural ventilation is limited. However, the higher airflow region is generally limited to the zone below the fan. The non-uniform distribution of airflow is also affected by the furniture layout and airflow from window openings. This study attempts to evaluate the effect of the different window-opening patterns on the airflow inside naturally ventilated bedrooms, having a ceiling fan for air movement with numerical simulations and on-site measurements. The airflow pattern created by a ceiling fan in a room with furniture is modelled and simulated with ANSYS Fluent 2019 R3. The results were validated with on-site measurements and compared with the literature. The air velocity was measured in bedrooms of three different sizes. It was observed that the opening of windows created a better distribution of air irrespective of room size. The non-uniformity of the air velocity is reduced from 76% to 39% with the opening of windows in the larger-sized room. The reduction in non-uniformity is influenced by the location of windows also. The practice of opening windows along with the induced air movement by ceiling fans results in a better distribution of air in the space. Practical application : People tend to depend mainly on ceiling fans even if windows are open in naturally ventilated rooms. A study of patterns of non-uniform distribution of airflow can help designers to improve comfort conditions by specifying the number and location of fans and windows while designing room furniture layout. This aids the building services engineers to provide thermal comfort without always depending on alternative active ventilation strategies.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"43 1","pages":"23 - 39"},"PeriodicalIF":1.7,"publicationDate":"2021-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211024084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47818546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-08DOI: 10.1177/01436244211020465
Manander Singh, Ryan Sharston
The paper presents a review of existing literature in the field of coupling Computational Fluid Dynamics (CFD) with Building Energy Simulations (BES) to better predict indoor environmental conditions and building energy implications. CFD is capable of providing a detailed analysis of airflow profile and temperature gradients in the space as well as better prediction of heat transfer involving convection and radiation. Whereas BES can provide dynamically changing boundary conditions to CFD to facilitate a precise transient analysis. Combining the two simulations provides a powerful framework to accurately predict building performance parameters. The review examines the variables exchanged between the two simulations and establishes that the Convective Heat Transfer Coefficient (CHTC) as the most important exchanged variable that can significantly improve the accuracy of energy simulations. Issues regarding the application of co-simulation mechanism are then discussed in terms of simulation discontinuities, along with strategies adopted by researchers to overcome the same. In the later sections, the review evaluates the applicability of co-simulation from the perspective of year-long building energy simulations and presents an overview of methods used in research to implement the same. Finally, the conclusions are discussed and the scope for future research in the field is presented. Practical implication: The review presents a critical analysis of essentially all major coupling strategies that can be used to perform a BES-CFD coupled analysis along with their strengths, limitations and possible application scenarios. Additionally, the problems associated with establishing the co-simulation are examined and various adopted solutions are presented along with methods implemented towards extending the practical applicability of such an analysis to encapsulate year-long simulations.
{"title":"A literature review of building energy simulation and computational fluid dynamics co-simulation strategies and its implications on the accuracy of energy predictions","authors":"Manander Singh, Ryan Sharston","doi":"10.1177/01436244211020465","DOIUrl":"https://doi.org/10.1177/01436244211020465","url":null,"abstract":"The paper presents a review of existing literature in the field of coupling Computational Fluid Dynamics (CFD) with Building Energy Simulations (BES) to better predict indoor environmental conditions and building energy implications. CFD is capable of providing a detailed analysis of airflow profile and temperature gradients in the space as well as better prediction of heat transfer involving convection and radiation. Whereas BES can provide dynamically changing boundary conditions to CFD to facilitate a precise transient analysis. Combining the two simulations provides a powerful framework to accurately predict building performance parameters. The review examines the variables exchanged between the two simulations and establishes that the Convective Heat Transfer Coefficient (CHTC) as the most important exchanged variable that can significantly improve the accuracy of energy simulations. Issues regarding the application of co-simulation mechanism are then discussed in terms of simulation discontinuities, along with strategies adopted by researchers to overcome the same. In the later sections, the review evaluates the applicability of co-simulation from the perspective of year-long building energy simulations and presents an overview of methods used in research to implement the same. Finally, the conclusions are discussed and the scope for future research in the field is presented. Practical implication: The review presents a critical analysis of essentially all major coupling strategies that can be used to perform a BES-CFD coupled analysis along with their strengths, limitations and possible application scenarios. Additionally, the problems associated with establishing the co-simulation are examined and various adopted solutions are presented along with methods implemented towards extending the practical applicability of such an analysis to encapsulate year-long simulations.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"43 1","pages":"113 - 138"},"PeriodicalIF":1.7,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211020465","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47808244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-25DOI: 10.1177/01436244211020470
S. Efthymiopoulos, H. Altamirano, Y. Aktas
Internal wall insulation is one of the few, possibly, the only feasible solution to efficiently reduce heat losses through the external walls of buildings where the application of external insulation is not an option, for example, in conservation areas. However, the application of this intervention may lead to unintended consequences, such as moisture accumulation and mould growth. Currently, no international standards and regulations exist to evaluate these hazards via non-destructive inspections. Air sampling through impaction and culture-based analysis was suggested in previous research as a potential non-disruptive methodology for interstitial mould testing. The method requires the perforation of the inner side of a wall and the creation of airflow through the operation of a pump, to allow the collection of particles from the confined space of interest. The present study aimed to assess the location of perforations and their effect on the airflow created and the airflow pattern variations due to changes in the airflow velocity at the outlet. Results regarding airflow features such as the turbulence intensity, dynamic pressure and volume-averaged velocity were also extracted and discussed. Practical application : The rapid changes in climate and net-zero emissions targets call for major improvements of the existing building stock towards a more sustainable future. The installation of internal wall insulation is one of the few and might be the only feasible solution for the efficient reduction of heat losses through uninsulated walls. However, this intervention might lead to moisture accumulation and thus moisture-related problems such as mould growth. This study aims to build upon previous work on interstitial mould growth assessment and contribute to the development of a well-defined testing protocol for building professionals.
{"title":"The effect of the airflow pattern inside air gaps on the assessment of interstitial mould: A theoretical approach","authors":"S. Efthymiopoulos, H. Altamirano, Y. Aktas","doi":"10.1177/01436244211020470","DOIUrl":"https://doi.org/10.1177/01436244211020470","url":null,"abstract":"Internal wall insulation is one of the few, possibly, the only feasible solution to efficiently reduce heat losses through the external walls of buildings where the application of external insulation is not an option, for example, in conservation areas. However, the application of this intervention may lead to unintended consequences, such as moisture accumulation and mould growth. Currently, no international standards and regulations exist to evaluate these hazards via non-destructive inspections. Air sampling through impaction and culture-based analysis was suggested in previous research as a potential non-disruptive methodology for interstitial mould testing. The method requires the perforation of the inner side of a wall and the creation of airflow through the operation of a pump, to allow the collection of particles from the confined space of interest. The present study aimed to assess the location of perforations and their effect on the airflow created and the airflow pattern variations due to changes in the airflow velocity at the outlet. Results regarding airflow features such as the turbulence intensity, dynamic pressure and volume-averaged velocity were also extracted and discussed. Practical application : The rapid changes in climate and net-zero emissions targets call for major improvements of the existing building stock towards a more sustainable future. The installation of internal wall insulation is one of the few and might be the only feasible solution for the efficient reduction of heat losses through uninsulated walls. However, this intervention might lead to moisture accumulation and thus moisture-related problems such as mould growth. This study aims to build upon previous work on interstitial mould growth assessment and contribute to the development of a well-defined testing protocol for building professionals.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"42 1","pages":"639 - 651"},"PeriodicalIF":1.7,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211020470","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41995973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-21DOI: 10.1177/01436244211017786
F. Tahmasebi, Yan Wang, Elizabeth Cooper, Daniel Godoy Shimizu, S. Stamp, D. Mumovic
The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application : This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.
{"title":"Window operation behaviour and indoor air quality during lockdown: A monitoring-based simulation-assisted study in London","authors":"F. Tahmasebi, Yan Wang, Elizabeth Cooper, Daniel Godoy Shimizu, S. Stamp, D. Mumovic","doi":"10.1177/01436244211017786","DOIUrl":"https://doi.org/10.1177/01436244211017786","url":null,"abstract":"The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application : This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"43 1","pages":"5 - 21"},"PeriodicalIF":1.7,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211017786","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49384749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-17DOI: 10.1177/01436244211019635
D. Ibarra-Zárate, Gustavo Navas-Reascos, AL Padilla-Ortiz
The most common noise sources in buildings are related to Heating, Ventilating and Air Conditioning (HVAC) systems, plumbing systems, electrical systems and exterior sources. Passive Noise Control (PNC) techniques in buildings have been implemented in several ways. The aim of this work is to analyses the use of silencer to attenuate the noise in the ducts that are part of the ventilation systems in buildings, internal combustion systems, fans, gas conduction systems, boilers, etc. The main objective of a silencer is to reduce the transmission of noise, disturbing as little as possible the circulation of gas or liquid. In the first instance, the silencers are classified as reactive and dissipative, depending on whether the attenuation of the noise is produced by reflective or dissipative mechanisms, respectively. In a reactive silencer, the losses occur essentially due to the reflections of the sound waves in impedance discontinuities, such as widening or narrowing of the tube. In dissipative silencers, the flow is in contact with a large surface of absorbent material. The attenuation of the noise is then produced by visco-thermal losses in the porous material. In this work, a practical issue will be addressed with a noise reduction of 19 dBA in 60 Hz. Practical application Noise is a current issue in residential areas that could lead to health problems for people. The origin of these noises within buildings is very diverse, one of them is produced by ducts. Appling the PNC technique in modern building construction would be a good prevention practice. For this reason, in this project a PNC system was carried out in the ducts of a residential building, which could be used as a praiseworthy solution, avoiding problems for the inhabitants of these spaces.
{"title":"Passive noise control in buildings: An engineering case study of ducted systems","authors":"D. Ibarra-Zárate, Gustavo Navas-Reascos, AL Padilla-Ortiz","doi":"10.1177/01436244211019635","DOIUrl":"https://doi.org/10.1177/01436244211019635","url":null,"abstract":"The most common noise sources in buildings are related to Heating, Ventilating and Air Conditioning (HVAC) systems, plumbing systems, electrical systems and exterior sources. Passive Noise Control (PNC) techniques in buildings have been implemented in several ways. The aim of this work is to analyses the use of silencer to attenuate the noise in the ducts that are part of the ventilation systems in buildings, internal combustion systems, fans, gas conduction systems, boilers, etc. The main objective of a silencer is to reduce the transmission of noise, disturbing as little as possible the circulation of gas or liquid. In the first instance, the silencers are classified as reactive and dissipative, depending on whether the attenuation of the noise is produced by reflective or dissipative mechanisms, respectively. In a reactive silencer, the losses occur essentially due to the reflections of the sound waves in impedance discontinuities, such as widening or narrowing of the tube. In dissipative silencers, the flow is in contact with a large surface of absorbent material. The attenuation of the noise is then produced by visco-thermal losses in the porous material. In this work, a practical issue will be addressed with a noise reduction of 19 dBA in 60 Hz. Practical application Noise is a current issue in residential areas that could lead to health problems for people. The origin of these noises within buildings is very diverse, one of them is produced by ducts. Appling the PNC technique in modern building construction would be a good prevention practice. For this reason, in this project a PNC system was carried out in the ducts of a residential building, which could be used as a praiseworthy solution, avoiding problems for the inhabitants of these spaces.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"42 1","pages":"751 - 762"},"PeriodicalIF":1.7,"publicationDate":"2021-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211019635","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42939719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-02DOI: 10.1177/01436244211013645
Rajat Gupta, Alastair Howard, M. Davies, A. Mavrogianni, I. Tsoulou, E. Oikonomou, P. Wilkinson
This paper brings together objective and subjective data on indoor temperature and thermal comfort to examine the magnitude and perception of summertime overheating in two London-based care homes occupying modern and older buildings. Continuous monitoring of indoor and outdoor temperature, relative humidity and CO2 levels was conducted in summer 2019 along with thermal comfort surveys and semi-structured interviews with older residents and staff of the care settings. Indoor temperatures were found to be high (>30°C) with bedroom temperatures often higher at night than daytime across both care settings. Limited opening due to window restrictors constrained night-time ventilation. Overheating was prevalent with four out of the five monitored bedrooms failing all four overheating metrics investigated. While 35–42% of staff responses perceived indoor temperatures to be uncomfortably hot, only 13–19% of resident responses were found to do so, indicating that elderly residents tend to be relatively insensitive to heat, leaving them open to overheating without realising it. Residents and staff in the modern care setting were less satisfied with their thermal conditions. As hybrid buildings, care settings need to keep both residents and staff comfortable and healthy during hot weather through night-time ventilation, management of heating and supportive institutional practices. Practical application: Care home designs have focused on keeping residents warm through the winter, neglecting the risks of summertime overheating. Care homes are hybrid buildings serving as living spaces for vulnerable older residents and offices/workspaces for staff. Providing comfort to both groups during periods of hot weather is challenging. Opportunities for ventilation are limited by Health & Safety regulations that mandate up to 10 cm maximum window openings and institutional practices that result in windows routinely kept closed, particularly at night. Utilising natural and where possible cross-ventilation should be considered along with external shading. Heating should be managed to avoid unwanted heat gains in the summer.
{"title":"Examining the magnitude and perception of summertime overheating in London care homes","authors":"Rajat Gupta, Alastair Howard, M. Davies, A. Mavrogianni, I. Tsoulou, E. Oikonomou, P. Wilkinson","doi":"10.1177/01436244211013645","DOIUrl":"https://doi.org/10.1177/01436244211013645","url":null,"abstract":"This paper brings together objective and subjective data on indoor temperature and thermal comfort to examine the magnitude and perception of summertime overheating in two London-based care homes occupying modern and older buildings. Continuous monitoring of indoor and outdoor temperature, relative humidity and CO2 levels was conducted in summer 2019 along with thermal comfort surveys and semi-structured interviews with older residents and staff of the care settings. Indoor temperatures were found to be high (>30°C) with bedroom temperatures often higher at night than daytime across both care settings. Limited opening due to window restrictors constrained night-time ventilation. Overheating was prevalent with four out of the five monitored bedrooms failing all four overheating metrics investigated. While 35–42% of staff responses perceived indoor temperatures to be uncomfortably hot, only 13–19% of resident responses were found to do so, indicating that elderly residents tend to be relatively insensitive to heat, leaving them open to overheating without realising it. Residents and staff in the modern care setting were less satisfied with their thermal conditions. As hybrid buildings, care settings need to keep both residents and staff comfortable and healthy during hot weather through night-time ventilation, management of heating and supportive institutional practices. Practical application: Care home designs have focused on keeping residents warm through the winter, neglecting the risks of summertime overheating. Care homes are hybrid buildings serving as living spaces for vulnerable older residents and offices/workspaces for staff. Providing comfort to both groups during periods of hot weather is challenging. Opportunities for ventilation are limited by Health & Safety regulations that mandate up to 10 cm maximum window openings and institutional practices that result in windows routinely kept closed, particularly at night. Utilising natural and where possible cross-ventilation should be considered along with external shading. Heating should be managed to avoid unwanted heat gains in the summer.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"123 ","pages":"653 - 675"},"PeriodicalIF":1.7,"publicationDate":"2021-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211013645","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41285882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.1177/0143624421991470
R. Cohen, K. Desai, Jennifer Elias, Richard Twinn
The UKGBC Net Zero Carbon Buildings Framework was published in April 2019 following an industry task group and extensive consultation process. The framework acts as guidance for achieving net zero carbon for operational energy and construction emissions, with a whole life carbon approach to be developed in the future. In consultation with industry, further detail and stricter requirements are being developed over time. In October 2019, proposals were set out for industry consultation on minimum energy efficiency targets for new and existing commercial office buildings seeking to achieve net zero carbon status for operational energy today, based on the performance levels that all buildings will be required to achieve by 2050. This was complemented by modelling work undertaken by the LETI network looking into net zero carbon requirements for new buildings. In January 2020 UKGBC published its guidance on the levels of energy performance that offices should target to achieve net zero and a trajectory for getting there by 2035. This paper describes the methodology behind and industry perspectives on UKGBC’s proposals which aim to predict the reduction in building energy intensity required if the UK’s economy is to be fully-powered by zero carbon energy in 2050. Practical application: Many developers and investors seeking to procure new commercial offices or undertake major refurbishments of existing offices are engaging with the ‘net zero carbon’ agenda, now intrinsic to the legislative framework for economic activity in the UK. A UKGBC initiative effectively filled a vacuum by defining a set of requirements including energy efficiency thresholds for commercial offices in the UK to be considered ‘net zero carbon’. This paper provides all stakeholders with a detailed justification for the level of these thresholds and what might be done to achieve them. A worked example details one possible solution for a new office.
{"title":"Net zero carbon: Energy performance targets for offices","authors":"R. Cohen, K. Desai, Jennifer Elias, Richard Twinn","doi":"10.1177/0143624421991470","DOIUrl":"https://doi.org/10.1177/0143624421991470","url":null,"abstract":"The UKGBC Net Zero Carbon Buildings Framework was published in April 2019 following an industry task group and extensive consultation process. The framework acts as guidance for achieving net zero carbon for operational energy and construction emissions, with a whole life carbon approach to be developed in the future. In consultation with industry, further detail and stricter requirements are being developed over time. In October 2019, proposals were set out for industry consultation on minimum energy efficiency targets for new and existing commercial office buildings seeking to achieve net zero carbon status for operational energy today, based on the performance levels that all buildings will be required to achieve by 2050. This was complemented by modelling work undertaken by the LETI network looking into net zero carbon requirements for new buildings. In January 2020 UKGBC published its guidance on the levels of energy performance that offices should target to achieve net zero and a trajectory for getting there by 2035. This paper describes the methodology behind and industry perspectives on UKGBC’s proposals which aim to predict the reduction in building energy intensity required if the UK’s economy is to be fully-powered by zero carbon energy in 2050. Practical application: Many developers and investors seeking to procure new commercial offices or undertake major refurbishments of existing offices are engaging with the ‘net zero carbon’ agenda, now intrinsic to the legislative framework for economic activity in the UK. A UKGBC initiative effectively filled a vacuum by defining a set of requirements including energy efficiency thresholds for commercial offices in the UK to be considered ‘net zero carbon’. This paper provides all stakeholders with a detailed justification for the level of these thresholds and what might be done to achieve them. A worked example details one possible solution for a new office.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"42 1","pages":"349 - 369"},"PeriodicalIF":1.7,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0143624421991470","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42682632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.1177/0143624421996989
Josien Ajc Buijze, A. Wright
Passive building design reduces a building’s energy consumption through mainly non-mechanical design strategies. The Passive House (or Passivhaus) Standard certifies such buildings that comply with its strict energy performance criteria. Achieving the Standard is very challenging for dwellings in extreme climates. There is limited knowledge of the Standard’s potential in Arctic regions, particularly the High Arctic. Through a review of the literature and energy modelling of a hypothetical dwelling, the challenges in achieving the Standard in Longyearbyen (78°N), Norway are investigated. Very low temperatures and 112 days without daylight create a high heating demand. Whereas previous studies measured actual building performances or used simple calculations, the findings in this investigation show the limitations of individual design parameters and technical limits of the building envelope. In theory the Standard can be achieved in Longyearbyen; however, the potential in practice is low due to the very tight margins in the heating criteria. The results show the significant impact of applying contextual (climatic) adjustments to the boundary conditions of the Standard. The investigation could contribute to a discussion on modifying the Passive House Standard for dwellings in the High Arctic and improving building design for the region. Practical application : Current knowledge regarding energy efficient building performance in Arctic climates is limited, while the urgency for improved efficiencies is extremely high. The modelling in this work shows the valuable impact of contextual adjustments to the Passive House boundary conditions; the impact of individual design parameters; and the potential for significant energy savings through adopting passive house principles for dwelling design in Longyearbyen or similar climates. This investigation could encourage new policy making, additional research and the development of an optimized Passive House Standard that considers High Arctic climate conditions, thus encouraging new energy efficient building construction in cold climates.
{"title":"The potential for the Passive House standard in Longyearbyen – the High Arctic","authors":"Josien Ajc Buijze, A. Wright","doi":"10.1177/0143624421996989","DOIUrl":"https://doi.org/10.1177/0143624421996989","url":null,"abstract":"Passive building design reduces a building’s energy consumption through mainly non-mechanical design strategies. The Passive House (or Passivhaus) Standard certifies such buildings that comply with its strict energy performance criteria. Achieving the Standard is very challenging for dwellings in extreme climates. There is limited knowledge of the Standard’s potential in Arctic regions, particularly the High Arctic. Through a review of the literature and energy modelling of a hypothetical dwelling, the challenges in achieving the Standard in Longyearbyen (78°N), Norway are investigated. Very low temperatures and 112 days without daylight create a high heating demand. Whereas previous studies measured actual building performances or used simple calculations, the findings in this investigation show the limitations of individual design parameters and technical limits of the building envelope. In theory the Standard can be achieved in Longyearbyen; however, the potential in practice is low due to the very tight margins in the heating criteria. The results show the significant impact of applying contextual (climatic) adjustments to the boundary conditions of the Standard. The investigation could contribute to a discussion on modifying the Passive House Standard for dwellings in the High Arctic and improving building design for the region. Practical application : Current knowledge regarding energy efficient building performance in Arctic climates is limited, while the urgency for improved efficiencies is extremely high. The modelling in this work shows the valuable impact of contextual adjustments to the Passive House boundary conditions; the impact of individual design parameters; and the potential for significant energy savings through adopting passive house principles for dwelling design in Longyearbyen or similar climates. This investigation could encourage new policy making, additional research and the development of an optimized Passive House Standard that considers High Arctic climate conditions, thus encouraging new energy efficient building construction in cold climates.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"42 1","pages":"307 - 325"},"PeriodicalIF":1.7,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0143624421996989","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47335820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.1177/0143624421991964
Jamie Risner, A. Sutherland
The average carbon intensity (gCO2e/kWh) of electricity provided by the UK National Grid is decreasing and becoming more time variable. This paper reviews the impact on energy calculations of using various levels of data resolution (half hourly, daily, monthly and annual) and of moving to region specific data. This analysis is in two parts, one focused on the potential impact on Part L assessments and the other on reported carbon emissions for existing buildings. Analysis demonstrated that an increase in calculated emissions of up to 12% is possible when using an emissions calculation methodology employing higher resolution grid carbon intensity data. Regional analysis indicated an even larger calculation discrepancy, with some regions annual emissions increasing by a factor of ten as compared to other regions. This paper proposes a path forward for the industry to improve the accuracy of analysis by using better data sources. The proposed change in calculation methodology is analogous to moving from using an annual average external temperature to using a CIBSE weather profile for a specific city or using a future weather file. Practical application: This paper aims to quantify the inaccuracy of a calculation methodology in common use in the industry and key to building regulations (specifically Building Regulations Part L – Conservation of Fuel and Power) – translating electricity consumption into carbon emissions. It proposes an alternative methodology which improves the accuracy of the calculation based on improved data inputs.
{"title":"Static grid carbon factors – Can we do better?","authors":"Jamie Risner, A. Sutherland","doi":"10.1177/0143624421991964","DOIUrl":"https://doi.org/10.1177/0143624421991964","url":null,"abstract":"The average carbon intensity (gCO2e/kWh) of electricity provided by the UK National Grid is decreasing and becoming more time variable. This paper reviews the impact on energy calculations of using various levels of data resolution (half hourly, daily, monthly and annual) and of moving to region specific data. This analysis is in two parts, one focused on the potential impact on Part L assessments and the other on reported carbon emissions for existing buildings. Analysis demonstrated that an increase in calculated emissions of up to 12% is possible when using an emissions calculation methodology employing higher resolution grid carbon intensity data. Regional analysis indicated an even larger calculation discrepancy, with some regions annual emissions increasing by a factor of ten as compared to other regions. This paper proposes a path forward for the industry to improve the accuracy of analysis by using better data sources. The proposed change in calculation methodology is analogous to moving from using an annual average external temperature to using a CIBSE weather profile for a specific city or using a future weather file. Practical application: This paper aims to quantify the inaccuracy of a calculation methodology in common use in the industry and key to building regulations (specifically Building Regulations Part L – Conservation of Fuel and Power) – translating electricity consumption into carbon emissions. It proposes an alternative methodology which improves the accuracy of the calculation based on improved data inputs.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"42 1","pages":"257 - 277"},"PeriodicalIF":1.7,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0143624421991964","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48039084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.1177/01436244211001497
Z. Bai, Yanfeng Li, Jin Zhang, A. Fewkes, Hua Zhong
This study investigated the optimal design of a capillary heat exchanger device for the heat pump system and its innovative engineering application in a building. The overall aim was to use a capillary heat exchanger to obtain energy in coastal areas for promoting renewable energy in low-carbon building design. Initially, the main factors affecting the efficiency of the capillary heat exchanger were identified, a mathematical model was then established to analyse the heat transfer process. The analysis showed the flow rate and the capillary length are the key factors affecting the efficiency of the capillary heat exchanger. Secondly, to optimize the structural design of the capillary heat exchanger, the heat energy transfer is calculated with different lengths of the capillary under various flow rates in summer and winter conditions, respectively. Thirdly, a typical building is selected to analyse the application of the capillary heat exchanger for extracting energy in the coastal area. The results show the performance of the selected capillary heat exchanger heat pump system, in winter, the heat energy transfer rate is 60 W/m2 when the seawater temperature is 3.7 °C; in summer, the heat energy transfer rate is 150 W/m2 when the seawater temperature is 24.6 °C. Finally, the above field test results were examined using a numerical simulation model, the test and simulation results agree with each other quite well. This paper is conducive in promoting the development of the capillary heat exchanger heat pump as an innovative sustainable technology for net-zero energy and low carbon buildings using renewable energy in coastal areas. Practical application: A recently proposed capillary heat exchanger is used as an energy extraction and utilisation device to obtain energy in coastal areas for promoting renewable energy in low-carbon building design. This paper explores the application of a capillary heat exchanger as both cold and heat sources for application in typical low-rise buildings. The analysis of the heat energy transfer rate of a typical low-rise building located in a coastal area in summer and winter provides guidance for the application of capillary heat exchangers.
{"title":"Research on the design and application of capillary heat exchangers for heat pumps in coastal areas","authors":"Z. Bai, Yanfeng Li, Jin Zhang, A. Fewkes, Hua Zhong","doi":"10.1177/01436244211001497","DOIUrl":"https://doi.org/10.1177/01436244211001497","url":null,"abstract":"This study investigated the optimal design of a capillary heat exchanger device for the heat pump system and its innovative engineering application in a building. The overall aim was to use a capillary heat exchanger to obtain energy in coastal areas for promoting renewable energy in low-carbon building design. Initially, the main factors affecting the efficiency of the capillary heat exchanger were identified, a mathematical model was then established to analyse the heat transfer process. The analysis showed the flow rate and the capillary length are the key factors affecting the efficiency of the capillary heat exchanger. Secondly, to optimize the structural design of the capillary heat exchanger, the heat energy transfer is calculated with different lengths of the capillary under various flow rates in summer and winter conditions, respectively. Thirdly, a typical building is selected to analyse the application of the capillary heat exchanger for extracting energy in the coastal area. The results show the performance of the selected capillary heat exchanger heat pump system, in winter, the heat energy transfer rate is 60 W/m2 when the seawater temperature is 3.7 °C; in summer, the heat energy transfer rate is 150 W/m2 when the seawater temperature is 24.6 °C. Finally, the above field test results were examined using a numerical simulation model, the test and simulation results agree with each other quite well. This paper is conducive in promoting the development of the capillary heat exchanger heat pump as an innovative sustainable technology for net-zero energy and low carbon buildings using renewable energy in coastal areas. Practical application: A recently proposed capillary heat exchanger is used as an energy extraction and utilisation device to obtain energy in coastal areas for promoting renewable energy in low-carbon building design. This paper explores the application of a capillary heat exchanger as both cold and heat sources for application in typical low-rise buildings. The analysis of the heat energy transfer rate of a typical low-rise building located in a coastal area in summer and winter provides guidance for the application of capillary heat exchangers.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"42 1","pages":"333 - 348"},"PeriodicalIF":1.7,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01436244211001497","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48973328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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