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The “District Heating Wall”: A Synergistic Approach to Achieve Affordable Carbon Emission Reductions in Old Terraced Houses  [PDF]
Claire Frost, Fan Wang, Paul Woods, Robert MacGregor
Low Carbon Economy (LCE) , 2012, DOI: 10.4236/lce.2012.323016
Abstract: One effective method to help the UK achieve GHG emission reduction targets is to reduce and decarbonise the heat demand of solid-walled terraced houses, as there are over 2.5 million such buildings making up a significant proportion of the whole building stock. Currently measures are achieved separately: the heat demand could be reduced by application of External Wall Insulation (EWI) or decarbonised through low carbon heat supplied by District Heating Networks (DHN). However, when installed individually, both these technologies face economic cost barriers. This study presents a novel solution that combines district heating pipes into external wall insulation—the District Heating Wall (DHWall) —and provides a systematic and quantitative assessment on its effects on the heating loads and its associated carbon emissions and capital costs. First a dynamic thermal model was developed to predict the heat demand of a case study terraced house with and without EWI. Two district heating networks were then sized to transport the required heat to the house-conventional and DHWall. The DHWall was compared to existing options and initial design parameters cal- culated. The study found application of EWI reduced space heating demand by 14%. The DHWall could reduce mains pipe inside diameter by 47% and reduce network pipe lengths by 20% and require no civils cost. Together these factors reduced DH capital costs by 76%. For one terraced house, the DHWall saved 34 tonnes of carbon over a 20year period compared to 8tonnes saved by EWI alone. Such savings were achieved at 39% of the cost/tonne. The mains pipe of the DHWall was calculated to have an inside diameter of 32.6 mm. The minimum insulation thickness required for solid walls to reach U-values of 0.3 W/m2K was calculated to be 120 mm of mineral wool or 65 mm of phenolic foam. The study concludes the DHWall has potential to contribute to GHG emission reductions by increasing market penetration of DH and EWI and should be investigated further.
Hybrid and Reflective Insulation Assemblies for Buildings  [PDF]
David W. Yarbrough, Khar San Teh, Lim Chin Haw, Elias Salleh, Sohif Mat, M. Yusof Sulaiman
Journal of Power and Energy Engineering (JPEE) , 2016, DOI: 10.4236/jpee.2016.47004
Abstract:

Materials with a low thermal emittance surface have been used for many years to create reflective insulations that reduce the rate of heat flow across building envelopes. Reflective insulation technology is now being combined with other energy conserving technologies to optimize overall thermal performance. The basis for the performance of reflective insulations and radiant barriers will be discussed along with the combination of these materials with cellular plastic or mineral fiber insulations to form hybrid insulation assemblies. Calculations of thermal resistance for enclosed reflective air spaces and current field data from Southeast Asia will be presented. These data show that reductions in heat transfer across the building enclosure can be effectively reduced by the use of enclosed reflective air spaces and attic radiant barriers. Reflective technology increases the overall thermal resistance of the building enclosure when used to insulate poured concrete structures.

Energy savings and emission reductions in industrial boilers  [PDF]
Saidur R.
Thermal Science , 2011, DOI: 10.2298/tsci091014046s
Abstract: In this paper energy use of boiler fan motors has been estimated using energy audit data. Energy savings using VSD by modulating fan speed has been estimated as well. Bill savings and associated emission reductions using VSD have been estimated and presented in this paper. It has been found that 139,412 MWh, 268,866, 159,328 MWh, and 99,580 MWh electrical energy can be saved for 40%, 60%, 80% and 100% motor loadings, respectively for 60% speed reduction. Corresponding bill savings for the aforementioned energy savings have been found to be US$7,318,335, US$14,113,933, US$8,363,812, and US135,911,944 for 40%, 60%, 80% and 100% motor loadings, respectively for 60% speed reduction. Along with energy savings, 69,770,744 kg, 134,558,329 kg, 79,738,065 kg, 49,836,603 kg of CO2 emission can be avoided for the associated energy savings as a result of energy savings using VSD for 40%, 60%, 80% and 100% motor loadings. Moreover, 32,503,558 GJ of fossil fuel can be saved for the flue gas temperature reduction as a result of reducing fan motor speed reduction. Flue gas energy savings for oxegen trim system has been estimated and found to be 549,310,130 GJ for 16.9% of excess air reduction with payback period less than a day.
Daylight Savings Calculation Technique for Smart Buildings  [PDF]
Dariusz Kacprzak, Ioan Tuleasca
Intelligent Control and Automation (ICA) , 2013, DOI: 10.4236/ica.2013.41014
Abstract:

This publication presents a technique of quantifying energy savings due to daylight. The technique is designated to be used in smart buildings or similar applications where daylight harvesting is welcomed. The technique is divided into three stages. In the first stage an optical sensor is evaluated for its P (power)-E (illumination) response characteristics. In the second stage the calibration of room properties is carried out. In the final stage photometric calculations are performed, and energy savings are calculated. The major advantage of the proposed approach is to determine energy savings during the design stage of a building, not after the building construction or retrofitting. The information obtained from the calculations is useful for investors, future tenants and environmentalists.

Energy Costs of Energy Savings in Buildings: A Review  [PDF]
Yvan Dutil,Daniel Rousse
Sustainability , 2012, DOI: 10.3390/su4081711
Abstract: It is often claimed that the cheapest energy is the one you do not need to produce. Nevertheless, this claim could somehow be unsubstantiated. In this article, the authors try to shed some light on this issue by using the concept of energy return on investment (EROI) as a yardstick. This choice brings semantic issues because in this paper the EROI is used in a different context than that of energy production. Indeed, while watts and negawatts share the same physical unit, they are not the same object, which brings some ambiguities in the interpretation of EROI. These are cleared by a refined definition of EROI and an adapted nomenclature. This review studies the research in the energy efficiency of building operation, which is one of the most investigated topics in energy efficiency. This study focuses on the impact of insulation and high efficiency windows as means to exemplify the concepts that are introduced. These results were normalized for climate, life time of the building, and construction material. In many cases, energy efficiency measures imply a very high EROI. Nevertheless, in some circumstances, this is not the case and it might be more profitable to produce the required energy than to try to save it.
Thermoeconomics as a tool for the design and analysis of energy savings initiatives in buildings connected to district heating networks  [cached]
Vittorio Verda,Albana Kona
International Journal of Thermodynamics , 2012, DOI: 10.5541/ijot.422
Abstract: District Heating (DH) is a rational way to supply heat to buildings in urban areas. This is expected to play an important role in future energy scenarios, mainly because of the possibility to recover waste heat and to integrate renewable energy sources. Even if DH is a well known technology, there are open problems to face. Some of these problems are related to tendencies to reduce design and operation temperatures, the improvement of control strategies, connection of new users to existing networks, implementation of energy savings initiatives and the access of multiple heat producers to the same network. This paper aims to show that exergy is an appropriate quantity for the analysis of DH systems and thermoeconomics can be profitably used to improve their design and operation. Three possible applications of thermoeconomic theories are presented: variation of supply temperature along the heating season, opportunities to connect new users, effects of energy savings initiatives in buildings connected with the network.
Fuelwood Savings and Carbon Emission Reductions by the Use of Improved Cooking Stoves in an Afromontane Forest, Ethiopia  [PDF]
Elisabeth Dresen,Ben DeVries,Martin Herold,Louis Verchot,Robert Müller
Land , 2014, DOI: 10.3390/land3031137
Abstract: In many Sub-Saharan African countries, fuelwood collection is among the most important drivers of deforestation and particularly forest degradation. In a detailed field study in the Kafa region of southern Ethiopia, we assessed the potential of efficient cooking stoves to mitigate the negative impacts of fuelwood harvesting on forests. Eleven thousand improved cooking stoves (ICS), specifically designed for baking Ethiopia’s staple food injera, referred to locally as “ Mirt” stoves, have been distributed here. We found a high acceptance rate of the stove. One hundred forty interviews, including users and non-users of the ICS, revealed fuelwood savings of nearly 40% in injera preparation compared to the traditional three-stone fire, leading to a total annual savings of 1.28 tons of fuelwood per household. Considering the approximated share of fuelwood from unsustainable sources, these savings translate to 11,800 tons of CO 2 saved for 11,156 disseminated ICS, corresponding to the amount of carbon stored in over 30 ha of local forest. We further found that stove efficiency increased with longer injera baking sessions, which shows a way of optimizing fuelwood savings by adapted usage of ICS. Our study confirms that efficient cooking stoves, if well adapted to the local cooking habits, can make a significant contribution to the conservation of forests and the avoidance of carbon emission from forest clearing and degradation.
Energy savings due to daylight and artificial lighting integration in office buildings in hot climate
Nagib T. Al-Ashwal, Ismail M. Budaiwi
International Journal of Energy and Environment , 2011,
Abstract: Reducing energy consumption while maintaining acceptable environmental quality in buildings has been a challenging task for building professionals. In office buildings, artificial lighting systems are a major consumer of energy and can significantly contribute to building cooling load. Furthermore, although reliable, artificial lighting does not necessarily provide the required quality of lighting. Significant improvement in lighting quality and energy consumption can be achieved by proper integration of daylight and artificial lighting. The objective of this study is to investigate the energy performance of office buildings resulting from daylight and artificial lighting integration in hot climates. A parametric analysis is conducted to find the impact of different window design parameters, including window area, height and glazing type, on building energy performance. Results have shown that as much as 35% reduction in lighting energy consumption and 13% reduction in total energy consumption can be obtained when proper daylighting and artificial lighting integration is achieved.
Evaluation of energy efficiency measures applied in public buildings (schools & hospitals) in Serbia
Stankovi? Sini?a,Campbell Neil,Maksimovi? Du?ko,Cvjetkovi? Tanja
Spatium , 2009, DOI: 10.2298/spat0920001s
Abstract: The Serbian Energy Efficiency Project 1 (SEEP1 - Design and Supervision Support for Implementation of the Energy Efficiency Improvements in Public Buildings in Serbia), funded by a credit from The World Bank, has involved the energy efficient refurbishment of 28 public buildings in Serbia (12 hospitals and 16 schools). The major goal of the project has been implementation of the energy efficiency improvements in public buildings in Serbia and the verification of the energy and cost savings as well as CO2 emission reductions achieved through implementation of the energy efficiency measures. Significant energy consumption savings have been achieved for all refurbished buildings with annual savings in the range of 15% to 63% and an average of 40% over entire project. Associated annual CO2 emission reductions vary between 15% to 64% with an average of 42%. The average specific space heating annual energy consumption for the hospitals monitored was ~339 kWh/m2 and has been reduced down to ~205 kWh/m2 after refurbishment. The average specific space heating annual energy consumption for the schools monitored was ~243 kWh/m2 and has been reduced down to ~144 kWh/m2 after refurbishment. The simple payback period (SPP) on investment across all buildings was found to be about 7.5 years. For hospitals, due to their 24/7 operation, the average SPP is 5.3 years and for schools is 12.8 years.
The public health benefits of insulation retrofits in existing housing in the United States
Jonathan I Levy, Yurika Nishioka, John D Spengler
Environmental Health , 2003, DOI: 10.1186/1476-069x-2-4
Abstract: We modeled energy savings with a regression model that extrapolated findings from an energy simulation program. Reductions of fine particulate matter (PM2.5) emissions and particle precursors (SO2 and NOx) were quantified using fuel-specific emission factors and marginal electricity analyses. Estimates of population exposure per unit emissions, varying by location and source type, were extrapolated from past dispersion model runs. Concentration-response functions for morbidity and mortality from PM2.5 were derived from the epidemiological literature, and economic values were assigned to health outcomes based on willingness to pay studies.In total, the insulation retrofits would save 800 TBTU (8 × 1014 British Thermal Units) per year across 46 million homes, resulting in 3,100 fewer tons of PM2.5, 100,000 fewer tons of NOx, and 190,000 fewer tons of SO2 per year. These emission reductions are associated with outcomes including 240 fewer deaths, 6,500 fewer asthma attacks, and 110,000 fewer restricted activity days per year. At a state level, the health benefits per unit energy savings vary by an order of magnitude, illustrating that multiple factors (including population patterns and energy sources) influence health benefit estimates. The health benefits correspond to $1.3 billion per year in externalities averted, compared with $5.9 billion per year in economic savings.In spite of significant uncertainties related to the interpretation of PM2.5 health effects and other dimensions of the model, our analysis demonstrates that a risk-based methodology is viable for national-level energy efficiency programs.Generally, the benefits of energy efficiency programs are expressed in terms of the economic payback that will accrue for individuals or organizations. To introduce environmental benefits into this framework, some investigators have quantified the emission reductions related to the decreased use of electricity and fossil fuel [1,2], including criteria air pollutants
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