Must attic ventilation be preserved in energy retrofits?

2019 ◽  
Vol 37 (4) ◽  
pp. 461-472
Author(s):  
William Rose
Keyword(s):  
Vapor Pressure ◽  
Energy Efficient ◽  
Design Methodology ◽  
Air Leakage ◽  
Content Type ◽  
Buoyancy Flow ◽  
Spreadsheet Model ◽  
Radiation Exchange ◽  
Moisture Performance ◽  
Ashrae Standards

Purpose The addition of thermal insulation into attics along with air-tightening of the ceiling plane is a common first step in making homes more energy efficient. Attic ventilation was introduced decades ago on the assumption that air leakage across the ceiling was inevitable and not correctible – this was before the era of spray-applied foams. Often attic ventilation is provided at roof eaves, and ensuring good insulation in their location is critical to avoid cold corners in the rooms below. So may vents be blocked in the course of energy retrofits? The paper aims to discuss this issue. Design/methodology/approach This study consists of a simple spreadsheet model of attic performance. The model is built using material from ASHRAE Handbook Fundamentals and ASHRAE Standards. It includes: Glaser calculations for temperature, vapor pressure and vapor pressure excess; radiation exchange – solar and sky; buoyancy flow assumption for leakage from indoors; wind flow assumption for leakage from outdoors; and change in attic air RH as assumed indicator of change in sheathing moisture performance. Findings The model results show that lowered moisture contributions across air-tightened ceilings may compensate effectively for added insulation (which lowers the attic air temperature) and reduced moisture dilution from attic ventilation. Originality/value These results provide support for the policy of allowing attic ventilation reductions that are proportionate to ceiling air leakage reductions as part of weatherization efforts. Given the limitations of the model, continued field observations remain critical.

Energy consultants calculating sustainability for residential buildings

Facilities ◽  
2019 ◽  
Vol 37 (11/12) ◽  
pp. 825-838 ◽  
Author(s):  
Roger Andre Søraa ◽  
Håkon Fyhn ◽  
Jøran Solli
Keyword(s):  
Design Process ◽  
Energy Efficient ◽  
Design Methodology ◽  
Residential Buildings ◽  
Qualitative Interviews ◽  
Implementation Process ◽  
Building Sector ◽  
Content Type ◽  
Practical Implications

PurposeThis paper aims to investigate the role of a particular energy calculator in enhancing the energy efficiency of existing homes by asking how this calculator was developed and how it is domesticated by craftspeople working as energy consultants.Design/methodology/approachThe study is based on qualitative interviews with users and producers of the energy calculator (n= 22), as well as participation in energy consultation training.FindingsThe paper finds that, in the energy calculator, there is a striking lack of connection between the domestication and script because of lack of energy consultants’ involvement in the design and implementation process.Practical implicationsThe enrolment of energy consultants as energy calculator users earlier in and throughout the design process could be valuable in making the transition to an energy-efficient and environmentally friendly building sector.Social implicationsThe paper argues for recognition of the role of energy consultants, especially craftspeople, as participants in the design process for tools of governance. This is a call to acknowledge the value of particular skills and experiences possessed by craftspeople doing home consultation.Originality/valueBy understanding the intricate developer–user synchronicity in tools developed for upgrading the building sector, energy mitigation can be made more effective.

DC-link voltage selection for a multi-MW wind turbine

2014 ◽  
Vol 33 (5) ◽  
pp. 1722-1740
Author(s):  
Poopak Roshanfekr ◽  
Torbjörn Thiringer ◽  
Sonja Lundmark ◽  
Mikael Alatalo
Keyword(s):  
Wind Turbine ◽  
Energy Efficient ◽  
Design Methodology ◽  
Synchronous Generators ◽  
Maximum Torque ◽  
Voltage Level ◽  
Content Type ◽  
Permanent Magnet Synchronous Generators ◽  
Selection For ◽  
Maximum Torque Per Ampere

Purpose – The purpose of this paper is to investigate how the dc-link voltage for the converter of a wind generator should be selected, i.e. to determine the losses in the generator and the converter when using various dc-link voltage levels. Design/methodology/approach – To presents the efficiency evaluation of 5 MW wind turbine generating systems, two 5 MW surface mounted permanent magnet synchronous generators (PMSG) with medium and low rated voltage is designed. A two-level transistor converter is considered for ac/dc conversion. Three different dc-link voltage levels are used. By using these voltage levels the PMSG is utilized in slightly different ways. Findings – It is found that the system with the lower voltage machine has slightly higher annual energy efficiency compare to the higher voltage system. Furthermore, it is shown that the best choice for the dc-link voltage level is a voltage between the minimum voltage which gives the desired torque and the voltage which gives Maximum Torque Per Ampere. Originality/value – A procedure as well as investigations with quantified results on how to find the highest complete drive system efficiency for a wind turbine application. Based on two given PMSG, the most energy-efficient dc-link voltage has been established.

Enabling energy-efficient renovation: the case of vertical extension to buildings

2019 ◽  
Vol 19 (1) ◽  
pp. 2-14 ◽  
Author(s):  
Rikard Sundling ◽  
Åke Blomsterberg ◽  
Anne Landin
Keyword(s):  
Life Cycle ◽  
Environmental Impact ◽  
Energy Efficient ◽  
Design Methodology ◽  
Data Gathering ◽  
Low Energy ◽  
Content Type ◽  
Vertical Extension ◽  
Profit Analysis ◽  
Energy Plus

Purpose This paper is based on a study of six similar buildings built in Gothenburg, Sweden, in 1971, which were in urgent need of renovation. A life cycle profit analysis shows how four competing concepts were evaluated to find a financially viable renovation concept; additionally, the environmental impacts of these renovation concepts using a life cycle assessment are presented. Design/methodology/approach Four renovation concepts are compared to find the most appropriate concept, namely, minimalist, code-compliant, low-energy and low-energy plus vertical extension concepts. The methods used for comparison are life cycle profit analysis and life cycle impact assessment; the methods used for data gathering included site visits, interviews, document study, co-benefits study and energy simulation. Findings The findings show that vertical extension supported the energy-efficient renovation of the buildings and that the combination of low-energy and the vertical extension had the highest return on investment and the lowest environmental impact. The selected concept for renovating the remaining five buildings combined was the low-energy plus vertical extension. Additional benefits from vertical extension include more apartments in central locations for the housing company, a wider variety of apartment layouts and a wider range of tenants. Drawbacks include increased use of infrastructure, green space and common appliances, as well as gentrification. Originality/value This study shows how a vertical extension can financially enable an energy-efficient renovation and further lower its environmental impact. Benefits and drawbacks of densification are also highlighted to better understand the implementation of vertically extending a building.

Green publishing with green technologies

2012 ◽  
Vol 30 (3) ◽  
pp. 381-383 ◽  
Author(s):  
Katja Metz ◽  
Michael Seadle
Keyword(s):  
Energy Efficient ◽  
Design Methodology ◽  
Energy Sources ◽  
Energy Costs ◽  
Green Product ◽  
Electronic Publication ◽  
Green Technologies ◽  
Content Type ◽  
Dark Green ◽  
The Impact

PurposeIf libraries truly want to be ecologically responsible, they need also to consider the impact of book and journal production on the environment. This paper seeks to address this issue.Design/methodology/approachThe methodology looks at energy consumption in journal production.FindingsElectronic publication does not produce a perfectly green product, but more of a dark green one with many aspects where energy costs could be saved. A genuinely ecologically friendly publication process requires conscious planning and determination.Originality/valueUsers can stop demanding paper as well as electronic copies, and can also choose more energy‐efficient hardware and energy sources.

scholarly journals An empirical study on life cycle assessment of double-glazed aluminium-clad timber windows

2019 ◽  
Vol 37 (5) ◽  
pp. 547-564 ◽  
Author(s):  
Asif M.
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Construction Industry ◽  
Environmental Performance ◽  
Energy Efficient ◽  
Design Methodology ◽  
Powder Coating ◽  
Research Community ◽  
Embodied Energy ◽  
Content Type

Purpose Life cycle assessment (LCA) is a useful tool to determine the environmental performance of materials and products. The purpose of this paper is to undertake the LCA of double-glazed aluminium-clad timber windows in order to determine their environmental performance. Design/methodology/approach The scope of the LCA study covers the production and the use of windows over a 30-year life span. The LCA exercise has been carried out by auditing the materials and processes involved in the making of the windows. Windows production facilities were visited to investigate the respective quantities and embodied energy of the major constituting materials, i.e. timber, aluminium, glass, infill gases and auxiliary components. The main processes involved, i.e. powder coating of aluminium cladding profiles, glazing unit production and window assembly, were also examined. SimaPro software was used to calculate the environmental impacts associated with the windows for three types of glazing infills: Argon (Ar), Krypton (Kr) and Xenon (Xe). Findings Embodied energy of a standard sized (1.2 m×1.2 m) double-glazed aluminium-clad timber window is found to be 899, 1,402 and 5,400 MJ for Argon (Ar), Krypton (Kr) and Xenon (Xe) infill gases, respectively. It is also found that an Argon-filled window can lose 95,130 kWh of energy resulting into over 37,000 kg of CO2 emissions. Originality/value Besides carrying value for research community, the findings of this study can help the building and construction industry adopt windows that are energy-efficient and environmentally less burdensome. It can also help the concerned legislative bodied.

House builder opinions of energy-efficient homes in the UK

2014 ◽  
Vol 7 (3) ◽  
pp. 417-434 ◽  
Author(s):  
Nicola Callaghan ◽  
James Sommerville ◽  
Nigel Craig
Keyword(s):  
Energy Efficient ◽  
Design Methodology ◽  
Low Carbon ◽  
Content Type ◽  
The Past ◽  
Construction Methods ◽  
Zero Carbon ◽  
The Uk ◽  
House Building ◽  
High Effort

Purpose – This paper aims to study house builder opinions of energy-efficient homes in the UK. The days of inconsiderate construction methods and disregard for the environment are becoming a thing of the past. If zero carbon (Zc) standards are to be implemented across all new homes within the UK, it is essential that house builders are willing and able to construct such homes to the necessary standards and to the volumes required. Although new generations of low carbon (Lc) and energy-efficient homes are beginning to break into the marketplace, house builders remain reluctant to introduce complex technologies during high effort builds. Design/methodology/approach – The findings from questionnaire responses provide an indication of the views of house builders relating to the incentives encouraging and barriers preventing them from producing mass market energy-efficient homes. Findings – This paper has uncovered the views and opinions of house builders relating to energy-efficient homes. The findings provide evidence that the house building industry is not fully engaged with the energy-efficiency concept; that house builders portray an inconsistent level of confidence in their ability to deliver energy-efficient homes; and that Government targets are too ambitious. Originality/value – The findings within this paper provide an overview of the opinions of house builders relating to energy-efficient homes using statistical analysis.

Energy efficient and latency optimized media resource allocation

2016 ◽  
Vol 12 (1) ◽  
pp. 2-17 ◽  
Author(s):  
Masoud Nosrati ◽  
Ronak Karimi
Keyword(s):  
Resource Allocation ◽  
Energy Efficient ◽  
Design Methodology ◽  
Green Computing ◽  
Content Type ◽  
Cloud Systems ◽  
Bottle Neck ◽  
Overall Performance ◽  
Future Work ◽  
Resource Agent

Purpose This paper aims to provide a method for media resource allocation in Cloud systems for supporting green computing policies, as well as attempting to improve the overall performance of system by optimizing the communication latencies. Design/methodology/approach A common method for resource allocation is using resource agent that takes the budgets/prices of applicants/resources and creates a probability matrix of allocation according to the policies of system. Two general policies for optimization are latency optimization and green computing. Presented heuristic for latencies is so that the average latencies of communication between applicant and resource are measured, and they will affect the next decision. For gaining green computing, it is attempted to consolidate the allocated resources on smaller number of physical machines. So calculation formula of the price of each resource is modified to decrease the probability of allocating the resources on the machine with least allocated resources. Findings Results of proposed method indicates its success in both green computing and improving the performance. Experiments show decreasing 21.4 per cent of response time simultaneously with increasing tasks in the tested range. The maximum and minimum of saved energy is acceptable and reported as 79.2 and 16.8 per cent. Research limitations/implications Like other centralized solutions, the proposed method suffers from the limitations of centralized resource agent, like bottle neck. But the implementation of distributed resource agent is postponed to future work. Originality/value Proposed method presents heuristics for improving the performance and gaining green computing. The key feature is formulating all the details and considering pitch variables for controlling the policies of system.

Utilization of renewable energy sources in bioclimatic architecture in Greece

2016 ◽  
Vol 13 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Semiha Kartal ◽  
Ömer Chousein
Keyword(s):  
Energy Efficient ◽  
Design Methodology ◽  
Residential Buildings ◽  
Renewable Energy Sources ◽  
Environmental Parameters ◽  
Climatic Parameters ◽  
Climatic Zones ◽  
Content Type ◽  
Energy Efficient Buildings ◽  
High Share

Purpose The aim of this study is to propose solutions to ensure comfort conditions for users by taking advantage of the bioclimatic architecture. This could serve as a solution to the energy shortage problem. Design/methodology/approach In this context, 40 bioclimatic buildings located in Greece were analyzed. These bioclimatic buildings were classified according to their climatic zones, functions, parameters pertaining to the physical and built environment, and the passive methods used for heating, cooling and lighting. Findings The high share of residential buildings in the distribution of Greece’s bioclimatic buildings according to climatic zones can be attributed to the large number of users that residential buildings have when compared to other types of buildings. Among the physical environmental parameters, climatic parameters were found to be highly influential. Other parameters had less significant effects, depending on land conditions. Originality value This study revealed the importance of bioclimatic applications in creating energy-efficient buildings. It is also important in terms of setting an example for creating bioclimatic architectural profiles of other countries.

Characterisation of air permeability of common ceiling linings and penetrations

2019 ◽  
Vol 37 (4) ◽  
pp. 448-460
Author(s):  
Stephan Harald Rupp ◽  
Manfred Plagmann
Keyword(s):  
Indoor Air ◽  
Design Methodology ◽  
Moisture Flux ◽  
Air Permeability ◽  
Test Facility ◽  
Air Leakage ◽  
Climate Data ◽  
Indoor Climate ◽  
Content Type

Purpose Air permeability of ceiling linings is an important element in understanding air and moisture flux from living spaces into the roof cavity. Ideally, these two spaces are decoupled to avoid transportation of moist indoor air into the attic space, where it can lead to condensation on the cold roof cladding. The purpose of this paper is to experimentally characterise the air permeability of a variety of common ceiling types. The results are given as leakage functions. Characteristic leakage data are also given for several ceiling penetrations. A case study illustrates the relevance of these data. Design/methodology/approach A specially designed test facility allows the installation of different ceiling types of up to 38 m2 in area. Laminar flow elements are used to measure the volumetric flow across the ceiling while recording the pressure difference. The experimental data are fitted to the leakage function equation Q =c (ΔP)n. Ceiling penetrations are characterised in a similar way. For the case studies estimating the transport of moisture into the roof cavity, indoor climate data have been obtained using humidity and temperature sensors. Findings Air leakage functions are given for a number of common ceiling linings and ceiling penetrations. These data can be used in simulations aimed at modelling moisture flux into the roof cavities. In the case study, the authors also give indoor climate data of residential dwellings in New Zealand. Originality/value This paper addresses the need for robust ceiling air permeability data in whole-house temperature and moisture transport simulations.

scholarly journals Vulnerable adults in police custody

2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins
Keyword(s):  
Design Methodology ◽  
Research Literature ◽  
Police Custody ◽  
England And Wales ◽  
Content Type ◽  
Increased Risk ◽  
Vulnerable Adults

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.

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