Lessons from Developing Methods to Study the Relationship of Energy and Water Savings to Housing Conditions and Resident Health

Abstract

Energy- and water-saving have been promoted as ways of saving money while there has been controversy about the effects (if any) of such measures on resident health. In public housing in the US, energy saving has taken the form of Energy Savings Performance Contracts (ESPC) that pay for renovations out of future savings. In an attempt to test feasibility and pilot research methods we conducted a study of the relationship between gas and water use, exterior heat sensor locations, and basement ventilation with indices developed from resident-reported living conditions and health symptoms in a single housing development. The data sources that we had available to us were not ideal. In particular, we were unable to obtain water use data that coincided in time with our health survey data. Also, we did not have enough surveys in buildings with high water or gas use and had to pool those buildings with other buildings for analysis. Nevertheless, we found several associations between our measures of energy use and resident reports of health symptoms. The associations that we found were generally in the direction that energy and water savings were associated with fewer symptoms and fewer environmental problems. There is a need for studies that obtain better input data but that generally follow the approach we developed.     

Comparing indicators to rank strategies to save potable water in buildings

The main objective of this paper is to compare indicators based on energy consumption and financial savings to rank strategies to save potable water in buildings. The method is based on potable water savings, embodied energy, energy consumption for operation, and investment feasibility analysis; and it was applied to a school in the city of Florianópolis, southern Brazil. The strategies considered to save potable water were rainwater, greywater, water-efficient appliances, and their combinations. The embodied energy was estimated using indices of embodied energy per mass of material, and labour. The indicators used to rank the strategies were potential for potable water savings, index between potable water savings and embodied energy or total energy consumption, net present value, internal rate of return, discounted payback, and index between potable water savings and initial costs. All strategies and combinations were feasible, but the use of water-efficient appliances was the best. Amongst the indicators used to rank the strategies, five of them led to the same ranking. Such indicators can be applied to rank potable water saving strategies in other types of buildings and climates.     

Efficient energy use and well being

This paper reviews the evolution of energy use in Sweden since the early 1970s to shed light on the future, with emphasis on the role of energy efficiency. Between 1973 and 1989 improvements in end-use energy efficiency saved 8% of Sweden's primary energy use and 24% of Sweden's delivered energy use. These savings were concentrated in the residential and manufacturing sectors, with important savings also occurring in air travel and the heating of commercial buildings. Despite these accomplishments, we found that Sweden was well behind Denmark, FRGermany, Japan and the USA in energy savings during this period. At the beginning of the 1990s Sweden exhibited one of the most energy intensive economic structures in the OECD. Sweden now faces many dilemmas that will influence future energy use: the role of nuclear power, pricing and taxation policies for fuels and electricity, the future of subsidies for housing and travel, the role of Sweden's energy intensive exports, and indeed the very lifestyle of the Swedes.     

Assessing energy use and greenhouse gas emission savings from compact housing: a small-town case study

Data from the US Department of Energy show that single-family detached homes consume about 17% more energy per year than attached homes and roughly double that of units in large multi-family structures. While greater use of these compact housing types could reduce a community's energy use and greenhouse gas (GHG) emissions, most local climate action plans (CAPs) do not quantify those potential savings. This article describes how the climate action planning process in the Town of Blacksburg, Virginia has addressed residential sector GHG emissions and demonstrates a methodology applied in that community for estimating potential GHG reductions from compact housing. It finds that in an aggressive compact housing scenario GHG emissions from new housing could be decreased by as much as 36%, without factoring in additional energy conservation or efficiency measures. The article concludes with a discussion of the opportunities and challenges related to implementing compact housing in future residential development.     

Energy-efficient HVAC system through chillers’ capacity sizing for a library building

Heating, ventilating, and air-conditioning (HVAC) systems in commercial buildings consume the largest amount of energy. Recent surge in energy cost necessitates constant re-evaluation of HVAC system for most of the buildings. The objective of this study is to present the strategic approach on energy saving analysis of the HVAC system and chiller sizing optimization for a library building. Energy modeling code (eQUEST) for buildings simulation has been applied to verify and predict the long-term energy consumption of HVAC systems. To improve the accuracy of simulation results, the actual performance curves of the chillers and pumps were the inputs of curve fitting data from on-site field measurements data. Energy consumption data acquisition from the building energy management system (BEMS) for one year has been conducted comprehensively to calibrate energy modeling and to quantify energy saving results. The results revealed good agreement between energy modeling and BEMS data with the error of less than 10%. Besides, energy savings through the chillers’ sizing based on cooling load profile could be achieved satisfactorily by utilizing energy modeling by using the actual chiller performance curve. The energy saving for HVAC system can be obtained satisfactorily at the saving of 110,362 kWh per year. It is expected that the study will stimulate a more robust investigation of energy-efficient and cost-effective HVAC system specific for library buildings.     

WATER USE REDUCTIONS FROM RETROFIHNG INDOOR WATER FIXTURES1

ABSTRACT: A water use model was developed to estimate water savings from installation of low-flow showerheads and toilet displacement devices in residential housing. The model measures household water use in per capita terms with adjustments for age of occupants, household income, if occupants responsible for direct payment of water bill, and type of water fixtures. Detailed data on 308 single family residences involved with a pilot retrofit program in the Seattle, Washington, area were analyzed. We estimated per capita indoor water use to decline by 6.4 and 2.1 percent from complete installation of low-flow showerheads and toilet displacement devices, respectively.     

Potential for electricity savings by reducing potable water consumption in a city scale

Nowadays, it is very important that water and energy resources are used appropriately as this is a challenge to promote sustainable development. In some sectors, such as water and sewerage utilities, energy consumption depends on water consumption. The main objective of this work is to estimate the potential for electricity savings in a water and sewerage utility by reducing potable water consumption in the residential, commercial and public sectors in the city of Florianópolis, southern Brazil. These three sectors account for 98.9% of the total water consumption in the city. By using data related to energy consumption and costs that apply to the local water utility for water and sewage treatment, and also the potential for potable water savings over the three sectors, it is possible to estimate the potential for energy savings by reducing potable water consumption and sewage treatment. Potable water savings were estimated by using data available in the literature about water end-uses for different types of buildings located in Florianópolis. Three options were considered: installing dual-flush toilets, reusing greywater and using rainwater. The average potential for potable water savings were 30.0%, 53.4% and 60.3%, respectively, for the residential, commercial and public sectors. Thus, the average potable water savings amount to about 10,153,835 m³/year, and the electricity savings amount to 4.4 GW h/year, which would be enough to supply 1217 houses or flats in Florianópolis, with an average energy consumption of 300 kW h/month.     

Economic and environmental analysis of standard, high efficiency, rainwater flushed, and composting toilets

The current sanitation technology in developed countries is based on diluting human excreta with large volumes of centrally provided potable water. This approach is a poor use of water resources and is also inefficient, expensive, and energy intensive. The goal of this study was to compare the standard sanitation technology (Scenario 1) with alternative technologies that require less or no potable water use in toilets. The alternative technologies considered were high efficiency toilets flushed with potable water (Scenario 2), standard toilets flushed with rainwater (Scenario 3), high efficiency toilets flushed with rainwater (Scenario 4), and composting toilets (Scenario 5). Cost, energy, and carbon implications of these five design scenarios were studied using two existing University of Toledo buildings. The results showed that alternative systems modeled in Scenarios 2, 4, and 5 were viable options both from an investment and an environmental performance perspective. High efficiency fixtures that use potable water (Scenario 2) is often the most preferred method in high efficiency buildings due to reduced water use and associated reductions in annual water and wastewater costs. However, the cost, energy, and CO(2)EE analyses all showed that Scenarios 4 and 5 were preferable over Scenario 2. Cost payback periods of scenarios 2, 4 and 5 were less than 10 years; in the future, increase in water and wastewater services would further decrease the payback periods. The centralized water and wastewater services have high carbon footprints; therefore if carbon footprint reduction is a primary goal of a building complex, alternative technologies that require less potable water and generate less wastewater can largely reduce the carbon footprint. High efficiency fixtures flushed with rainwater (Scenario 4) and composting toilets (Scenario 5) required considerably less energy than direct energy demands of buildings. However, the annual carbon footprint of these technologies was comparable to the annual carbon footprint from space heating. Similarly, the carbon savings that could be achieved from Scenario 4 or 5 were comparable to a recycling program that can be implemented in buildings.     

天然气集输系统节能减排措施研究与实施

以丘东采油厂为例,从能源消耗结构、管理和技术三个方面,对天然气集输过程中能源消耗情况及清洁生产方案措施实施效果进行分析,确定影响节能减排的关键因素;通过节能减排技术的应用,采取节能管理措施,降低能源消耗,减少污染物排放,取得一定的效果。     

Optimizing angles of rooftop photovoltaics,ratios of solar to vegetated roof systems,and economic benefits,in Portland,Oregon, USA

This study analyzed insolation data to account for multiple scattering in calculating optimal tilt angles for stationary and seasonally moving photovoltaics on three different roof types in the US Pacific Northwest: vegetated roofs, white roofs, and dark roofs. Using these results, we modeled the energy savings for vegetated roofs and roofs covered in varying numbers of photovoltaic panels. We then calculated the net present value, internal rate of return, and other economic measures for all possible combinations of covering rooftops in mixes of photovoltaic arrays and vegetation, accounting for installation costs, proposed carbon taxes, stormwater management discounts, and other relevant factors. Our results quantify how, in the US Pacific Northwest and similar locations, photovoltaics produce higher returns on investment than do vegetated roofs for new buildings, while vegetated roofs produce better returns on investment than do photovoltaics for older buildings. This is important because in many areas, some buildings have photovoltaics when a vegetated roof would have been more cost and energy efficient, while other buildings have vegetated roofs when photovoltaics would have been more cost and energy efficient. Potential applications include modifying incentive programs and other policies to account properly for building age, use, and other relevant factors to ensure building owners make the most energy-efficient decisions between photovoltaic versus vegetated roof installation. Our research also demonstrates how positive returns on investment can be realized in the US Pacific Northwest and similar regions through vegetated roofs and photovoltaics provided they are each installed optimally.     

Sustainable development of building of extensive roof greening in Taiwan

Taiwan government specifies that the average roof thermal transmittance must be less than 0.8 (w/(m²·k)) for the design of all residential buildings in order to implement the policy of saving energy. However, self-disciplined architects practice the design of aesthetic roof to blend in with green landscape so that they urgently expect the academia to provide roof greening technical information to support their idea of designing green roofs for residential buildings. In this research, a single-family housing unit is used for investigating the possibility of applying extensive roof greening to achieve building sustainable development. The experiment tasks focused on the soil denudation caused by rainwater washing and replenishing the soil carbon by irrigating the soil with gray water. Using tap water to irrigate the green roof for 12, 16, and 14 weeks causes nitrogen, phosphate, and potassium, respectively, to be reduced to less than the original levels, respectively. Applying gray water to irrigate the green roof soil will raise the soil fertility by improving nitrogen and phosphate but not obvious for potassium.     

Water saving effect on integrated water resource management

This study proposes an improved integrated water resource management (IWRM), in which water conservation was analyzed for the entire water use process. A multi-objective optimization method was applied to optimize the IWRM, which investigated the reduction of freshwater consumption and the total water supply cost. Customer's preference for saving water and an end use analysis (EUA) was applied in the water conservation analysis. Taking Tianjin as the study area, a reduction in customer's economic pressure (EP) was utilized to evaluate the degree of the customer's preference for saving water. The results revealed that agriculture had a greater preference for saving water than other sectors, where as the public had the weakest motivation for saving water. Improving the transportation method could contribute 62.1% of the total water savings in the agriculture sector. The optimization of the IWRM demonstrated that the local freshwater savings would be 21.5%, and the total cost for water supplies would decrease by 13%. However, a government subsidy of 87.5 million Yuan would be needed. Additionally, by analyzing the change in the amount of water savings affected by water price, the appropriate water price increase range was suggested to be 1.5–1.7 times the original price.     

夜间自然通风降低办公室空调制冷能耗

夜间自然通风已经成功运用于许多被动制冷或低能耗写字楼中。介绍了夜间自然通风在写字楼中的适用性。在适当的温度条件下,建立热量计通风模型,以此来检验节能以及内部舒适度改善情况。研究发现,自然通风模式能够减少传统空调写字间的制冷能耗。采用"应用最佳"的原则,如提高气密性、内部发热及日晒生热的最小化等改善建筑结构能有效提高自然通风的节能性。     

Quantification of potable water savings by residential water conservation and reuse - A case study

To demonstrate the benefits of water conservation at the household level in regional Victoria in Australia, a family house “Sharland Oasis” was designed and built according to an ecologically sustainable design for improved water and energy efficiency. This study has demonstrated that the combined use of alternative water supplies together with water efficient appliances can save up to 77% of total potable water use compared to the average 1990s household water use in the same region considering the location and differing in water use approach. The use of rainwater inside the home alone saved up to 40% of potable water use. In addition to the water savings, there is a significant wastewater discharge saving achieved through the use of water conservation strategies and greywater reuse. A community survey undertaken in regional Victoria revealed that community receptivity for reusing greywater is highest for uses, such as watering gardens and flushing toilets; but it progressively decreased with increasing personal contact with greywater. Positive perception of greywater reuse needs to be encouraged through programs targeted at developing resources, skills and motivation for new water reuse practices and technologies, across a diverse range of social groups.     

油田企业节能减排的实践与探索

实施节能减排是建设资源节约型和环境友好型社会的重要举措,具有重要的现实意义和深远的历史意义。油田企业采取一系列措施,建立和完善各项节能减排制度,通过总结油田节能减排工作实践,提出下步节能减排的工作目标和指导思想,建议要突出工作重点,尤其是要推进能源节约、推行污染减排、加强资源综合利用、促进节水等方面,实现全方位节能减排。同时,应制定中长期工作规划,采取示范工程、开展创建活动、加快体制机制建设、强化基础工作、加大监督检查力度等措施,为企业实现又好又快发展提供政策、体制、机制保障。     

A novel radiant floor system: Detailed characterization and comparison with traditional radiant systems

ABSTRACT

Radiant floor systems have the potential to reduce energy consumption and the carbon footprint of buildings. This study analyzed a novel radiant panel configuration comprising a metal plate with small spikes that can be pressed into cement board or wood. The behavior of this configuration was simulated for different materials for the metal plate, spike dimensions, and varying spacing between spikes. An annual energy simulation model compared the radiant panel configuration with the traditional concrete-based system. Simulations were run under heating dominant, cooling dominant, and neutral conditions; significant cost savings and greenhouse gas emission reduction were seen across all scenarios.     

Evaluation of energy savings by using high efficiency motors in a thermal power station

This paper presents potential energy savings by installing high-efficiency motors instead of existing ones and their impact on greenhouse gases emissions reductions. This research study of the energy efficiency of electric motors has been performed in a typical thermal power plant. In the literature, the focus has been mainly on separate and away electric motors from operating facilities. The important advantage of this paper over other studies is that it uses the actual motors’ efficiency in the evaluation. The gains both in terms of electrical energy savings and in terms of financial economy by using high-efficiency motors have been discussed. As a result, the energy saving can be expected as 12.6% at the operating rate. This excellent result also reduces greenhouse gas emission by 1,423 tons every year. The analysis of the data provided an overview on energy losses often generated by the degradation and rewinding of electrical motors. This study represents very encouraging results that will help energy managers of industrial plants to become more involved in energy efficiency strategies.     

Linking Biological Integrity and Watershed Models to Assess the Impacts of Historical Land Use and Climate Changes on Stream Health

Land use change and other human disturbances have significant impacts on physicochemical and biological conditions of stream systems. Meanwhile, linking these disturbances with hydrology and water quality conditions is challenged due to the lack of high-resolution datasets and the selection of modeling techniques that can adequately deal with the complex and nonlinear relationships of natural systems. This study addresses the above concerns by employing a watershed model to obtain stream flow and water quality data and fill a critical gap in data collection. The data were then used to estimate fish index of biological integrity (IBI) within the Saginaw Bay basin in Michigan. Three methods were used in connecting hydrology and water quality variables to fish measures including stepwise linear regression, partial least squares regression, and fuzzy logic. The IBI predictive model developed using fuzzy logic showed the best performance with the R ² = 0.48. The variables that identified as most correlated to IBI were average annual flow, average annual organic phosphorus, average seasonal nitrite, average seasonal nitrate, and stream gradient. Next, the predictions were extended to pre-settlement (mid-1800s) land use and climate conditions. Results showed overall significantly higher IBI scores under the pre-settlement land use scenario for the entire watershed. However, at the fish sampling locations, there was no significant difference in IBI. Results also showed that including historical climate data have strong influences on stream flow and water quality measures that interactively affect stream health; therefore, should be considered in developing baseline ecological conditions.     

油气钻井节能减排及清洁生产措施实践

从钻井作业各环节进一步采取节能减排措施,对企业环境保护极为重要。结合四川油气田钻井作业实际,从生产过程中的八个环节较详细地分析论述了节能减排清洁生产的主要措施,以龙岗10井为清洁生产示范工程,介绍了其清洁生产与节能减排所取得的绩效,处理后水质达到《污水综合排放标准》(GB8978-1996)一级标准,清洁生产主要指标达到中国石油天然气集团公司规定的钻井清洁生产指标的二级指标要求。     

DEMAND SIDE MANAGEMENT OF WATER IN ONTARIO MUNICIPALITIES: STATUS,PROGRESS, AND OPPORTUNITIES1

ABSTRACT: Demand side management is being used increasingly by Ontario municipalities as a way to improve the efficiency of water use, defer the costs associated with constructing new water treatment works, and minimize the environmental impacts associated with supplying water. A comprehensive survey of 153 Ontario municipalities was completed in mid‐1998. These ranged in size from small rural townships (with populations as low as 500 people) to the province's largest urban center, Metropolitan Toronto, with a population of approximately 2.5 million people. The questionnaire measured the use of six broad types of demand side measures, including water pricing and metering; municipal by‐laws (ordinances) that promote water conservation; operational and maintenance measures to reduce water losses and consumption; water‐saving plumbing fixtures and devices; public participation programs that encourage water conservation; and other measures, such as water audits. Additionally, the survey collected data on implementation barriers and opportunities. Since the last comprehensive Ontario survey, conducted in 1987 by Kreutzwiser and Fea‐gan (1989), there has been an increase in the use of basic tools such as metering and pricing, plumbing fixtures, and public participation programs. Additionally, new initiatives, such as water audits and computerized monitoring equipment, are being used. However, in many areas opportunities exist to make better use of demand side measures. Unfortunately, municipal capacity to do so often is constrained by (among other factors) limited finances, lack of political will, and public resistance. Demonstration of real cost savings to consumers, and the development of specific goals and objectives for demand side management programs, are two important steps needed to overcome these challenges.