Dual Flush Toilets Research Articles

On the Necessity for Improving Water Efficiency in Commercial Buildings: A Green Design Approach in Hot Humid Climates

Water, a fundamental and indispensable resource necessary for the survival of living beings, has become a pressing issue in numerous regions worldwide due to scarcity. Urban areas, where the majority of the global population resides, witness a substantial consumption of blue water, particularly in commercial buildings. This study investigates the potential for enhancing water efficiency within an ongoing high-rise office building construction situated in a tropical climate. The investigation utilizes the green building guidelines of leadership in energy and environmental design (LEED) through a case-study-based research approach. Strategies included using efficient plumbing fixtures (such as high air–water ratio fixtures and dual-flush toilets), the selection of native plants, implementing a suitable irrigation system, introducing a rainwater harvesting system (RWHS) and improving the mechanical ventilation and air conditioning (MVAC) system. The results showed a 55% reduction in water use from efficient fixtures, a 93% reduction in landscaping water needs and a 73% overall water efficiency with a RWHS from the baseline design. Additionally, efficient cooling towers and the redirection of condensed water into the cooling tower make-up water tank improved the overall water efficiency to 38%, accounting for the water requirements of the MVAC system. The findings of this study can contribute to more sustainable and water-efficient urban development, particularly in regions facing water scarcity challenges. The significance of these findings lies in their potential to establish industry standards and inform policymakers in the building sector. They offer valuable insights for implementing effective strategies aimed at reducing blue water consumption across different building types.

Sustainable practices in restaurants: customers’ perceptions of Brazil and other countries

This study aimed at comparing and contrasting consumers’ perceptions of sustainable practices in restaurants in Brazil and other countries. The data presented here was gathered through a questionnaire applied to restaurants’ consumers who lived in Brazil and in other 36 countries, by using a snowball technique. The findings show that consumers from around the world have similar perceptions regarding sustainable practices in the context of restaurants, as the most observed sustainable practices implemented in the restaurants they visit were identified as follows: implementing health protocols for customers, having open spaces for customer service, serving local/regional fruit juices, using dual flush toilet valve and using natural ventilation, while the main factors for choosing a restaurant were: service, comfort, waiting time, ambience, location, menu variety, price and local/regional cuisine. In addition, the findings expose that sustainable practices are not one of the top factors for choosing a restaurant.

Ecological approach towards sustainability in hotel industry

Today, every tourist wants a reason to remember the place they visit to feel the touch of serendipity. To exhilarate growing needs of tourist enthusiasts, it is essential to inculcate eco- friendly ways in hospitality methods while providing hotel amenities. Every tourist enthusiast wants to enhance their experience by getting more and more closely towards nature. As ‘green hotel’ or ‘eco hotel’ (in modern era widely known as “Ecotel”) serves the purpose poignantly by representing as a new concept in hospitality that claims to work for environment protection and preservation. As nature is a well-equipped hospitality and it is just a step away to bringing that to society by grown incumbents like us. Today plethora of modern opportunities in eco-friendly hospitality are in front of us like use of renewable resources like solar or wind energy, greywater recycling, local organic grown food, organic soaps and amenities, eco-friendly culinary arts, energy efficient lightings, biodegradable decomposition, natural ventilation system, eco-friendly dual flush toilets and much more. These factors in olio can be an impetus step in innovative hospitality. Travelers can feel the best of nature amenities here by itself. To serves them well, more and more green hotels to be formed with an open perspective to all by collaborating hospitality with divine healing therapy.

Eficiência energética em prédios de salas de aula naturalmente ventilados

Em 2014, foi publicada a Instrução Normativa 02/2014, do Ministério do Planejamento, Desenvolvimento e Gestão, obrigando os projetos de edificações e os retrofit de edificações públicas federais, com mais de quinhentos metros quadrados de área, a serem desenvolvidos buscando a Etiqueta Nacional de Conservação de Energia de Projeto nível A, de acordo com os Requisitos Técnicos de Qualidade para o Nível de Eficiência Energética de Edifícios Comerciais, de Serviços e Públicos (RTQ-C). O objetivo deste trabalho é verificar se projetos de prédios de salas de aula licitados por Instituições Federais de Ensino Superior (IFES) atendem à determinação da IN 02/2014 e, em caso negativo, como intervir para os projetos atingirem nível A. Foram analisados dez prédios naturalmente ventilados licitados por quatro IFES do Rio Grande do Sul, seguindo os procedimentos indicados no RTQ-C. Também foram realizadas simulações para verificar o consumo hipotético de energia se os edifícios fossem condicionados artificialmente. Como resultado, 60% dos projetos conseguiram alcançar o nível mais alto de eficiência energética, atendendo à Instrução Normativa. Também se verificou que, nos casos negativos, a substituição das lâmpadas tubulares fluorescentes por lâmpadas LED equivalentes e especificação de bacias sanitárias econômicas bastaria para os projetos obterem a classificação máxima.

Sustainable household water-saving and demand management options for Kabul City

Increasing water demand has led to water scarcity in many urban areas in the arid and semi-arid regions. Indeed, population growth and the expansion of urban and industrialized areas have put great pressure on water resources. Currently, Kabul city is facing groundwater shortage, which is the main source of potable water. Due to rapid urbanization and population growth, and climate impacts, the groundwater level is lowered (∼ 1m/year), which has led to many wells drying out in recent years since 1998. Therefore, this study focuses on alternative options to sustain water resources and achieve water sustainability through implementing water-saving practices, including tapping new water resources (rainwater harvesting), and some of the options (faucet aerators, low-flow showerheads, and dual flush toilets), others as gray-water reuse. To analyze the potential of rainwater in Kabul city, long-term precipitation data from 1960-1980 and 2006-2013 from several stations around the city are used. The rooftops of the dwellings assumed to account for 30% of the total land area, according to the State of Afghanistan City 2015 report. Moreover, existing household water efficiency is compared to the most efficient available technologies. The result indicated 346 mm annual average precipitation, and 38.0 million m3/Year the potential precipitation volume that could be harvest from dwellings rooftops in Kabul city. Moreover, the rainwater harvesting could produce an average of 29 L/capita/day (LCD) of water for domestic usage, with a maximum of 75 LCD in February, a minimum of 5 LCD in September, and an annual 9593 L/capita/year (LCY). If we manage the maximum months, then it could produce the full domestic usage (38.1 LCD) until July. Furthermore, in terms of demand management, we have performed a case study on Macrorayon’s (1st, 2nd, 3rd, 4th) apartments that if low flow fixtures were utilized, how much water could be saved? The Macrorayon Department estimates the service population of its system at 100,000 people, the volume of consumption calculated to be 12,500 m3/day (125 LCD). Results show that after application of low flow fixtures, per capita consumption can be reduced to 57 LCD, 2.08 MCM/Year would be saved; and an additional population of 119,298 people would be covered by water supply. The result of this study is essential for policymakers to adopt current and future water challenges in Kabul city.

Water Usage Patterns and Water Saving Devices in Households: A Case of Eastleigh, Nairobi

Water conservation measures are rapidly becoming a necessity in urban environments all over Africa and the world. There is little innovation and available information for homeowners, building professionals and practitioners to guide towards water conservation. Water scarcity has progressively increased over periods of time in Eastleigh due to increased population density from increased high-rise apartments. The study tries to establish how water usage patterns and water conservation devices can potentially reduce water consumption levels. In the study area, 96% of the families are faced with problems related to water supply and hence are forced to come up with water conservation and adaptation strategies due to the scarcity of water. The study used survey and descriptive research design, and collected data on water usage patterns and water conservation devices from a total of 230 households in Biafra and Sewage estates in the Eastleigh neighbourhood. The results indicated that 76% of the households did not have water saving devices while the other 24% had water saving devices such as the dual flush toilets, low flow high-efficiency faucet aerators, low flow plumbing fixtures and automatic shut-off nozzles. A unit increase in water saving devices will lead to a 0.512 decrease in water consumption level. The study recommends that low-income households use water saving devices and develop water management strategies such as water-saving plumbing fixtures, rainwater harvesting, and grey water reuse.

Water Use and Conservation Preferences Among Households in an Urbanizing Gradient

The effectiveness of water policies depends upon the behavioral features of users and factors influencing these processes. Behavioral changes such as a reduction in watering the lawns, reducing water pressure, and taking shorter showers can be used to design policies that can be effective. However, the most impactful changes come from technological modifications, including faucet aerators, water-efficient showerheads and washing machines, dual-flush toilets, and outdoor technology such as automatic sprinkler systems. A survey of households in Amherst, Hadley, and Northampton, of the Commonwealth of Massachusetts, USA, is used to measure such behavioral changes as well as technological adoptions along an urbanizing gradient. Objectives of this study are as follows: to assess developments under current and anticipated water conservation strategies in households along an urban gradient, to evaluate the preferences and motivating factors of individuals, and to determine how individuals value their water. Statistical modeling is used to analyze the household survey using several dependent variables, including conservation efforts and willingness to pay. Independent variables included location, economic, and demographic information. Results indicate that those with a higher income are likely to have more water-saving tools indoors and are willing to pay more than those with lower incomes. Age influenced total current conservation adoptions, while metering of water consumption is also significantly related to the indoor adoption of current technology and willingness to pay (WTP) for water infrastructure.

Evaluation of some water saving devices in urban areas: A case study from the Sultanate of Oman

Water Saving Devices (WSDs) sustain demands for potable water, soften impacts on supply systems and inflict a positive effect on wastewater treatment systems. This study evaluated the effect of some WSDs in Oman. A questionnaire survey and some case studies were used. The survey results revealed that the pipe line system network for water supply accounted for about 67.7%, whereas the rest mainly use tankers. Around 37.2% of the participants received consumed 25000 - 45000 liters per household per month. Case studies showed no significant difference in household water usage before and after installation of WSDs due to pre-installed aerators. Toilet bags and dual flush toilets were not effective promoting users to flush. However, WSDs were significantly effective in restaurants, mosques, hotels and government buildings. Water consumption in shopping centres and hospitals slightly decreased. Retrofitting programs that involve replacement of existing plumbing equipment and residential water audit programs are recommended.

The Impact of Demographic Factors, Beliefs, and Social Influences on Residential Water Consumption and Implications for Non-Price Policies in Urban India

In rapidly growing urban areas in India and the developing world, water demands typically exceed supply. While local governments may implement management programs to reduce demand for freshwater, water savings are dependent on the conservation behaviors of individuals. A household survey is presented here to examine residential water end uses and conservation behaviors in Jaipur, India. The survey explores end uses, engagement in conservation behaviors, and the influence of demographic factors, water sources, beliefs about water, and social pressures on these behaviors are tested. The survey was conducted at 248 households, including 29 households in the slums. Our study finds that while the majority of participants recognize the importance of water conservation, they do not necessarily conserve water themselves. Households report engaging most frequently in water-conservation behaviors that require little effort or financial investment. Multivariate analysis of variance (MANOVA) results and subsequent pairwise comparisons indicate higher incomes, longer water-supply durations, and the belief that droughts are preventable are positively correlated with overall amenability to adoption of water-conservation behaviors and technology. Binomial logistic regression analysis indicates that being in the age group 26–35, having higher income, and giving a neutral response about the responsibility of the government to provide relief during a drought were all predictors of the installation of dual-flush (DF) toilets. Education levels and water awareness were found to have no correlation with conservation behaviors or amenability to conservation technology adoption. Results are applied to examine their possible implications from a demand-management perspective and provide suggestions for further research and policy decisions.

Water-energy nexus in low-income houses in Brazil: the influence of integrated on-site water and sewage management strategies on the energy consumption of water and sewerage services

The water-energy nexus has been increasingly studied in order to elucidate the complex interdependence between water and energy resources, and, as a result, enhance management practices to conserve both resources alike. In this context, integrated water management plans have direct implications on the energy embodied into water and sewerage services. The objective of this study is to assess the potential for energy savings in water and sewerage services by means of on-site integrated water and sewage management strategies in low-income households in Florianópolis, Brazil. The studied water efficient measures include: (i) installation of water efficient fixtures (dual flush toilets and water efficient taps); (ii) reclamation of grey water from shower, washing basin, and laundry for toilet flushing; and (iii) rainwater use for laundry and toilet flushing. From the combination of these measures, the water and energy saving potential of seven integrated water and sewage management strategies were studied. Moreover, the water consumption pattern at ten low-income households with conventional and water efficient taps were empirically determined using water smart meters; whereas, the rainwater supply capacity was estimated by using the computer programme Netuno 4.0, and the grey water supply and sewage reduction capacities were determined using model equations. Rainwater harvesting alone appeared as the least favourable strategy for energy savings as the energy consumption would increase 4% compared to a centralised system; while the combination of water efficient fixtures and grey water reclamation gave rise to the greatest energy saving potential (48%). The findings of this study indicate that, from an energy management point of view, the sustainability of the water sector is primarily associated with the reduction of effluents to centralised systems, rather than the use of alternative water sources.

USmell: exploring the potential for gas sensors to classify odors in ubicomp applications relative to airflow and distance

Previous research has shown that gas sensors can be used to classify odors when used in highly controlled experimental testing chambers. However, potential ubicomp applications require these sensors to perform an analysis in less controlled environments, particularly at a distance. In this paper, we discuss our design of uSmell--a gas sensor system for sensing smell in ubicomp environments--and an evaluation of its basic efficacy, effects of airflow and distance on classification accuracy, and in an example application. Our system samples an odor fingerprint from eight metal oxide semiconductor (MOS) gas sensors every second. It then processes the time series data to extract three features that highlight how time and distance affect the eight MOS gas sensors' ability to react to the gas molecules released by an odor every 5 s; this generates 24 features in total that are then used to train a decision tree classifier. Using this approach, our system can classify a set of odors with 88 % accuracy when placed both in a small container with the samples and in open air 0.5---2 m from the odor samples. We also demonstrate its ability to classify odors in less controlled environments that might be targets for ubicomp applications by deploying it in a bathroom for a week. These results show the potential for applying this sensing toward the development of context-aware systems, such as lifelogging applications or those geared toward enhancing the sustainability of natural resources (e.g., an automatic dual-flush toilet that always uses an appropriate amount of water based on the user's toileting activities).

Evaluation of pollution prevention options in the municipal water cycle

Abstract The impact on water resources caused by municipal wastewater discharges has become a critical and ever-growing environmental and public health problem. In order to be able to efficiently address this problem, it is important to adopt an integrated approach that includes a decrease in and control of contamination at its source. These principles have been successfully applied in the industrial sector and now these concepts are also being applied to integrated water resources management. In this context the conceptual model of the Three Steps Strategic Approach (3-SSA) was developed, consisting of: 1) minimization and prevention, 2) treatment for reuse and 3) stimulated natural self-purification. This paper is focused on the first step. The assessment includes a case study in the expansion area of the city of Cali, Colombia (410,380 new inhabitants). The evaluation of alternatives is done using two different system boundaries: (1) reduction in water supply costs for households, savings associated with the drinking water infrastructure and the avoided costs in the infrastructure of additional sewerage and wastewater treatment facilities; and (2) only taking into account the reduction in water supply costs for households and the savings associated with the drinking water infrastructure. The alternatives of minimization and prevention were hierarchized using an analytic hierarchy process and grey relational analysis. A cost-benefit analysis was carried out to compare the highest ranked alternatives with the conventional approach, which considers a ‘business as usual scenario’ of high water use, end-of-pipe wastewater treatment plant and the conventional water supply system with drinking water quality for all uses. The best minimization and prevention alternatives for Cali's expansion zone were found to be those which consider dual flush toilets and the possibility of using rainwater harvesting for laundry purposes. However, the minimization and prevention alternatives considered are only viable if these are implemented in more than 20% of household units.

Assessment of Potable Water Savings in Office Buildings Considering Embodied Energy

The objective of this article is to assess the potential for potable water savings in office buildings located in Florianopolis, southern Brazil. The embodied energy of four alternatives to reduce potable water demand, i.e., rainwater harvesting, greywater reuse, dual-flush toilets and water-saving taps, was also assessed. The analyses took into account the potable water end-uses for ten buildings. The potential for potable water savings by using rainwater, as well as, the rainwater tank sizing were estimated using computer simulation. As for greywater reuse, it was considered that greywater from lavatory taps could be treated and reused to flush toilets. The potential for potable water savings by using water-saving plumbing fixtures was estimated by considering the replacement of toilets and taps. In order to estimate the embodied energy in the main components, each system was dimensioned and embodied energy indices were applied. The main result is that the potential for potable water savings by using dual-flush toilets ranges from 21.6 % to 57.4 %; by reusing greywater, it ranges from 6.8 % to 38.4 %; by using rainwater, it ranges from 6.1 % to 21.2 %; by using water-saving taps it ranges from 2.7 % to 15.4 %. However, by considering the embodied energy, the average for the ten buildings indicates that dual-flush toilets are the best choice as it is possible to obtain water savings of 5.50 m3/month per GJ of embodied energy, followed, respectively, by water-saving taps, greywater reuse and rainwater usage. The main conclusion is that the assessment of embodied energy should be considered when evaluating potable water savings in buildings as it helps to identify the best alternatives to save more water while causing less environmental impact.

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 m 3/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.

A Financial, Environmental and Social Evaluation of Domestic Water Management Options in the West Bank, Palestine

Water is one of the most valuable natural resources in the West Bank, Palestine. Due to its limited availability, it is a resource that needs particular protection. Although agriculture consumes most of the water (70%) in the West Bank, the domestic water supply is strategically not less important. It is the aim of this study to evaluate domestic water management options suitable for Palestinian conditions that contribute to achieving water sufficiency in the domestic water use in the house of tomorrow. A number of options were evaluated economically, environmentally and socially using the concept of life cycle impact assessment (LCIA). Results of the study showed that by introducing a combination of domestic water management options, a substantial decrease in the water consumption of more than 50% can be achieved, thereby reducing the pressure on the scarce water resources. The annual environmental impact of the in-house water use can be reduced in the range of 8%, when using low-flow shower head to 38% when using rainwater harvesting systems. Some of the options (faucet aerators, low-flow shower heads and dual flush toilets) were found to be financially attractive with a pay back period of less than their expected lives, others (rainwater harvesting, graywater reuse and dry toilets) were found to be financially unattractive because of the high investment. In the social context, it was found that introducing such options can improve the quality of life of those not having enough water. There is already a popular willingness to take part in water conservation in the domestic sector in the West Bank. The strongest driving force for using water conservation measures is the awareness that water is a scarce resource. It was concluded that, theoretically, the house of tomorrow can be largely independent in terms of water and sanitation. Education and awareness campaigns in the context of water management with a focus on non-traditional options are key to achieve such a house.

WHERE DOES THE WATER GO? BEST PRACTICE STOCK MODELING FOR WATER USING APPLIANCES

The water efficiency of toilets in Australia has increased significantly since the 1980's due to the development of the dual flush toilet, and the progressive reduction in average flush volumes with each new model. The accurate modelling of the average efficiency of toilets is very important as a component of demand forecasting, which itself is at its most powerful when it is disaggregated, and based on end use modeling. The stock mix of toilets has been modeled and calibrated using data from two yearly surveys of the toilet stock that have been undertaken since 1992. A lognormal function was found to most accurately represent the declining share of single flush toilets in the mix. The introduction of dual flush toilets has had a significant impact on total toilet demand in Australia. By 2007, the savings already achieved amount to 214 GL per year. An accelerated retrofit program would save an additional 79 GL per year.

Application of a residential end-use model for estimating cold and hot water demand, wastewater flow and salinity

The structure and data requirements of an end-use model for residential water demand and return flow are presented in a companion paper. This paper focuses on the practical application of the model. The model is first applied to confirm a few commonly observed water demand patterns: Seasonal variation in demand, the positive correlation between average annual daily water demand and stand size, and the increase in water demand, hot water demand and wastewater flow with an increase in household size. The convergence between the predicted model results and independently observed values by others encourages practical use of the model. Secondly, the effects of some specific water demand management measures are evaluated by adjusting selected model parameters. The measures include xeriscaping, the installation of dual-flush toilets and low-flow showerheads, pool ownership and pool cover use. The model provides a rapid means to obtain first estimates of the likely effects of different water demand management measures. WaterSA Vol.30 (3) 2004: 305-316

Washroom behaviour and users' perceptions of “novel” water-efficient appliances

A variety of washroom appliances are available which claim to be water efficient. However there are a number of “human” factors, which may adversely affect the water savings actually achieved when the appliances are installed. These were investigated as part of Thames Water's “Watercycle” project at the Millennium Dome, where a range of water efficient devices, such as infra-red controlled taps, waterless urinals and dual-flush toilets, were installed in the washrooms and compared to standard appliances. As well as monitoring actual metered water usage, to help understand how users interacted with the range of appliances, the work also involved a survey conducted by interview and an observational study of water using behaviour in the washrooms. The results highlighted significant differences between males and females, for example females were more likely to wash their hands following toilet use. With respect to “novel” dual flush toilets and waterless urinals, both fairly unusual in the UK, they were well received by users. In contrast, the infra-red controlled taps were found difficult to use and least likely to be accepted for use in the home. Relevant signage and labelling was found to have a positive effect on conservation and user opinions.

End use analysis: issues and lessons

Methodologies for end use analysis have been developed by different researchers in the energy and water fields and in different areas in the world over the last 20 years. While there are core features associated with the methodologies and models used, the differences can provide insight into the ways that they might be improved, as well as the differences that may be required in different regions and when models are used for different purposes. In addition to reviewing the field of end use analysis and appliance stock models, this paper will focus on two case studies. The first is the Sydney Water End Use Model, developed as part of the Sydney Water Least Cost Planning Study. This model has been developed and used to project the demand for water in Sydney over the next 20 years under business as usual scenario, as well as allow the projection of a number of scenarios which include major investment in water efficiency and effluent reuse programs as well as regulatory options to improve the efficiency of water using appliances in stalled in new buildings. Key features of the Sydney Water End Use Model include the fact that it takes into account the fact that the efficiency of toilets in Australia has a much larger range than (say) the US, in that the dual flush toilet was introduced in (to date) three stages. The model also accounts for projections of demographic and land use change which has been particularly dramatic in Sydney, particularly the movement to smaller occupancy rates in dwellings, and towards multi-family residential dwellings. The second case study will demonstrate the linkages between end use modeling of energy using and water using appliances. A model of residential energy use in Australia has been developed as part of a research project to develop greenhouse abatement scenarios for Australia, and many of the appliances modeled overlap with the water end use model, including clothes washing machines, dishwashers, showerheads and taps. This more recent modeling exercise has revealed the importance of key assumptions in standard stock modeling techniques, and highlighted the need for earlier starting dates for stock modeling. The process and results of these two case studies will be presented, and conclusions drawn about further improvements in end use analysis for both water and energy use. The linkage between the use of backcasting as a planning tool, and the use of end use analysis as a pre-requisite for the development of a demand management program is highlighted.