Water Consumption In Buildings Research Articles

Analysis of rainwater use in membrane-based semi-direct evaporative cooling of air

The trend of seeking solutions to reduce energy consumption in buildings is evident in the context of heating, ventilation, and air conditioning technologies. One such solution with low energy consumption is direct evaporative cooling systems. However, the use of such systems is associated with an increase in fresh water consumption in buildings. The article presents a novel approach to air cooling, taking into account the sustainable building aims of designing buildings with low energy consumption and water conservation. The proposed system is a membrane-based semi-direct evaporative cooling system, which is fed by harvested rainwater. The study analyzed the potential of rainwater harvesting for direct evaporative cooling in ten cities. The cities selected for the analysis of system operation, are located in different climates according to the Köppen-Geiger classification. Water consumption for cooling at a base temperature of 26.7 °C was estimated using a mathematical model of the membrane module. Furthermore, the number of evaporative cooling hours per year was determined for this temperature. The system under analysis achieved a high coefficient of performance (COP) and a seasonal coefficient of performance (SCOP) of up to 183 and 133, respectively. Depending on the location of the building, the annual water consumption of the system ranged from 150 to 8859 dm3. The rainwater harvesting provided up to 100 % of the evaporative cooling requirements. The proposed solution reduces tap water consumption and lowers the temperature of fresh air supplied to indoor spaces while consuming low energy.

Towards Reducing the Consumption of Drinking Water in Buildings as Part of the Circular Economy Model: Strengths–Weaknesses–Opportunities–Threats Analysis and Perspectives for Implementation

Progressive climate changes, drought resulting from them and the prospect of problems with access to water for people in cities mean that actions are being taken to minimize water use in buildings and to implement a circular economy in the water and wastewater sector. Within the water circular economy model, there is also a stage of “water consumption”. Minimizing water use in buildings undoubtedly has a number of advantages. However, it should be borne in mind that it may also have weaknesses, and if implemented on a large scale, it may be associated with certain threats. For these reasons, the aim of this paper is to critically analyze the possible directions of water management in buildings in order to reduce water consumption and increase the efficiency of its use. As part of the introduction, the model “towards a water circular economy for households” is presented and the possibilities of minimizing water consumption in buildings are discussed. The prospects for reducing the consumption of tap water are discussed in terms of existing opportunities, but also threats, barriers and limitations. A SWOT analysis of the implementation of drinking-water consumption reduction in cities is presented. The challenges faced by engineers, constructors, policy makers and consumers, and the potentialities for the development of this stage of the water life cycle, are considered. The conclusions summarize the current state and perspectives of water management in buildings. Based on the conducted analysis, suggested directions of activities for cities of the future in the technical, technological as well as socio-economic fields are indicated. There should be broad-based education, and efforts should be made to change the approach to designing and developing new guidelines. The implementation of minimizing water consumption should be accompanied by the control of possible negative effects and actions to mitigate them. In the transformation towards clean and available energy, future success should be seen in minimizing the consumption of drinking water in buildings.

Evaluasi Efisiensi Air Gedung Perkantoran Pada Musim Kering Pada Perencanaan Bangunan Gedung Hijau

Water is necessary for various human activities. The larger the population, the greater the water consumption. Harnessing rainwater and reusing recycled grey and black water can reduce consumption. Water efficiency needs to be a concern because of the limited availability of water and to maintain limited water availability. Water consumption in buildings for office functions is relatively high. Therefore, office buildings are very important to be designed as environmentally friendly buildings. Water efficiency is a criterion for eco-friendly buildings, more commonly known as green buildings. This research aims to improve water efficiency by utilizing rainwater and recycled water in the Waskita Karya building. The secondary data collection required is at the planning stage. The data collected are water-saving features, rainfall, building area of each floor, site plan, and other relevant data. Water efficiency calculations take into account wet and dry days. On wet days because water comes from rain, and on dry days, the water source is only from PDAM and recycled water. Software issued by the Directorate General of Copyright calculates the water balance. The calculation will result in water savings on dry days. Conventional water consumption amounted to 83,153 lt / day, water source from recycled grey water 29,216 lt / day, black water 14,143 lt / day, efficiency on dry days amounted to 76.8%. This research needs to be implemented so that building owners know their water consumption and can support green building performance and water cost savings.

Wireless water consumption sensing system for building energy efficiency: A visual-based approach with self-powered operation

The use of smart wireless remote water meters has become popular due to their efficiency in avoiding manual labor and automate meter reading. The current implementation of these measurement instruments often requires expensive external power sources and separate data aggregators, posing challenges for circuit safety and the goal of reducing carbon emissions in aging communities. In response, a novel wireless system has been developed to accurately measure water consumption in buildings. This system incorporates advanced machine learning techniques and utilizes the potential of water-based energy in a seamless manner. This novel methodology utilizes optical sensors to acquire visual data of water gauges and exploits machine learning techniques, specifically the AVSM model also called Advanced Visual Sensing Model (AVSM). This methodology employs a rigorous approach to achieve accurate metric determinations, thereby eliminating the necessity for additional hardware or excessive power configurations. Moreover, an integrated micro water generator has been seamlessly implemented, demonstrating the capability to effectively transfer energy to a lithium battery for the purpose of storage. This implementation guarantees consistent functionality and a significant decrease in reliance on external power supplies. The data augmentation procedure involves the stochastic manipulation of image luminance, resulting in encouraging results when used in conjunction with the AVSM model. Significantly, the dimensions of the model have been significantly decreased, while maintaining a commendable mean average precision (mAP). By leveraging this method and visual-based features, the system can contribute to overall building energy efficiency and reduce the burdens of manual meter reading while supporting CO2 emissions reduction as a feasible and cost-effective solution for building management, promoting sustainability, and advancing energy-efficient practices in old communities. This new wireless system for measuring water usage provides a practical and affordable way to enhance energy efficiency in buildings, lessen the workload of manual meter reading, and help meet carbon emissions reduction goals. As well as optimizing resource and energy use, this method also aligns with eco-friendly solutions to combat global warming and climate change.

Synchronization of water-energy consumption in residential and non-residential buildings during COVID-19

ABSTRACT COVID-19 has made working from home (WFH) a widely prevalent mode of work, resulting in highly complex changes of energy and water consumption in buildings. To understand these changes, this study applies the concept of water-energy nexus (WEN) in the analysis of energy and water data in residential and non-residential buildings in Ontario, Canada, before and during the pandemic. The study found the overall energy and water consumption of buildings exhibited a decreasing trend, with the most significant change found in water consumption. Energy and water consumption increased in residential buildings but decreased in non-residential buildings; the changes in energy and water consumption were synchronized over the WFH period. This study also elucidated that changes were related to the demographic and job attributes. When dealing with the peak load of residential consumption with a high consumption benchmark, due consideration should be given to the stronger synchronization of the two types of resources to improve the resilience of residences to cope with the uncertainty of unexpected large-scale public health crisis. Applying WEN to building resource consumption during WFH for the first time, the findings shed light on the need to enhance integrated water and energy management.

Innovative Optimization Model for Planning Upgrade and Maintenance Interventions for Buildings

Building operation and maintenance costs are reported to be the longest and most costly phase of a building’s life cycle, where it exceeds costs of design and construction. Although buildings are regularly maintained, water- and energy-saving investments are not often analyzed. This paper presents the development of a novel model for optimizing the selection of upgrade and maintenance interventions for existing buildings to minimize their equivalent annual operation and maintenance cost (EAOMC) while complying with specified annual budgets and building operational performance. The optimization model is developed in three main phases that focus on (1) identifying model decision variables and formulating objective function and constraints; (2) implementing the model computations using binary linear programming; and (3) analyzing the performance of the optimization model using a case study. The primary contributions this research adds to the body of knowledge are (1) a new computationally efficient model for identifying optimal selection of building upgrade and maintenance interventions to minimize EAOMC; (2) modeling reactive, preventive, and predictive maintenance strategies based on component types; (3) integrating a simulation-based upgrade and maintenance approach to evaluate energy and water consumption of buildings; and (4) integrating maintenance and upgrade interventions to maximize economic benefits from building operation by reducing operational and maintenance costs. The results of the case study illustrated the new capabilities of the model in identifying optimal upgrade and maintenance interventions for various operational budgets with up to 32% reduction in EAOMC.

Comprehensive Environmental Assessment of Rainwater Harvesting Systems: A Literature Review

The feasibility of installing rainwater harvesting systems in buildings is usually defined based primarily on economic analysis. In this perspective, we reviewed the literature related to water consumption in buildings, rainwater use, and environmental assessment tools to evaluate the impact of rainwater harvesting on the environment. Identifying water end uses in buildings showed a high potential for potable water savings through alternative sources (e.g., rainwater use for non-potable purposes). Most studies reviewed found potential for potable water savings from 20 to 65%. Moreover, the literature reported that rainwater harvesting systems might reduce the runoff volume from 13 to 91%. However, other possible benefits and impacts of the systems on water flow and the environment must be assessed in addition to the potential for rainwater harvesting. Life cycle assessment, life cycle cost assessment, and water balance modelling have been used in urban water management. Most life cycle studies reported that rainwater harvesting systems have better environmental performance than centralised systems. The water balance method may effectively determine the impacts these systems cause on the water cycle. Using life cycle assessment and the water balance method together is essential to evaluating rainwater harvesting systems integrated into the urban environment.

Rainfall data used for rainwater harvesting systems: a bibliometric and systematic literature review

Abstract The demand for water has led to an increase in scarcity events in several urban regions. In an urban context, water consumption in buildings plays an important role and rainwater harvesting is one of the ways that consumption can be reduced. One of the input variables for the dimensioning of rainwater tanks is the pluviometric regime's characteristics in the region where the rainwater harvesting system (RWHS) is to be installed. In this study, a bibliometric and systematic literature review was carried out on the types of rainfall data used in the dimensioning of the elements of RWHS. Worldwide, the most-used data comes from meteorological stations, with a historical series size of 30 years, however, other types of data and different sizes of historical series are also used. From this study, it was possible to synthesise the regions where differentiation data can be collected, as well as their characteristics, enabling the researchers to quickly access the definition of separation data collection parameters.

Methodology for Determining Sustainable Water Consumption Indicators for Buildings

The objective of this study was the definition and determination of sustainable water consumption indicators for activity categories, as well as the evolution of water consumption in commercial buildings. These indicators were determined through statistical analyses using Shewhart charts. Within a broader scope, the research proposed a methodology to automate sustainable management of water consumption in building operation using BIM–IoT–FM integration. The scientific rigor of the methodology was based on the precepts of design science research. The methods proposed for the construction of functionalities and the application of the reference indicators provided an optimized analysis of water consumption and the detection of excess consumption and leaks. The methodology, implemented in an online prototype, AquaBIM, could deliver a significant advance for building management. A conceptual test of AquaBIM evaluated the consumption indicators and validated our methodology through its application in a commercial building. The building consumption analyses showed a potential for approximately 15% savings. In addition, five requirements of the international sustainability certification AQUAHQE were met. The results of our research provide an innovative approach for the automation of sustainable building management and could be expanded to monitor and report on the consumption of other critical resources such as electricity and gas.

False alarm moderation for performance monitoring in industrial water distribution systems

While considerable attention has been given to data driven methods that analyse and control energy systems in buildings, the same cannot be said for building water systems. As a result, approaches which support enhanced efficiency in building water consumption are somewhat underdeveloped, particularly in industrial settings. Water consumption in industrial systems features non-stationarity (i.e., variations in statistical properties over time), making it challenging to distinguish between routine and non-routine water uses. In such scenarios, fault detection and diagnosis methods that leverage multivariate statistical process control with, for example, principal component analysis and detection indices (Hotelling T2-statistics and Q-statistics), can be successfully used to identify system alarms. However, even with these approaches there can be a high prevalence of false alarms leading to low industry uptake of fault detection and diagnosis systems, or where in place, alarms can be ignored. To efficiently detect and diagnose water distribution system faults, false alarms should be controlled through false alarm moderation approaches so that building managers/operators only need to focus on critical system alarms or system alarms with high risk levels. This paper utilises two statistical non-parametric false alarm moderation approaches (window-based, and trial-based) that generate a second control limit for T2-statistics and Q-statistics. The implementation of these false alarm moderation approaches was combined with principal component analysis to detect faults with real water time series data from two case-study sites. Using both approaches false alarms were reduced, and the overall performance and reliability of the fault detection and diagnosis approach was improved. The principal component analysis model with the window-based approach was shown to be particularly effective.

Water Balance Modelling as a Tool for Assessing the Environmental Impact of Urban Water Systems and Water Consumption in Buildings

Water Balance Modelling as a Tool for Assessing the Environmental Impact of Urban Water Systems and Water Consumption in Buildings

Methodology for estimating energy and water consumption patterns in university buildings: case study, Federal University of Roraima (UFRR)

Knowing water and energy consumption patterns sets the baseline for understanding their drivers and assessing the performance of potential measures to increase efficiency and/or reliability. These patterns can vary substantially depending on the building characteristics, on the building users and use, on the cultural, social, economic, environmental context in which the building is located, among many other factors. This article presents a general methodological framework for characterizing water and energy consumption patterns in buildings based on the evaluation of the characteristics of the equipments and appliances, as well as the type of users and the activities developed in each type of room. This allows estimating water and energy use, by end use per square meter and by roomtype. The methodological framework proposed was applied to the buildings of the Paricarana Campus of Federal University of Roraima (UFRR), Brazil, providing one of the few examples in the literature reporting water and energy consumption in university buildings in tropical climates. Universities, in most cases, represent large water and energy consumers with distinctive consumption drivers and patterns which have received limited attention when compared to other types of buildings (e.g., residential). The findings have shown that teaching rooms and administration rooms are the main consumers, representing 48% and 49% of the institution's energy and water consumption, respectively. Air conditioning is the biggest energy consumption (63%), while personal use represents 72% of the total water consumption in a building. The toilets represent a large water consumption in a university building (46.40%). Comparing different building uses, the central library is the highest consumer, due to the longest operating time and the highest occupational density. The methodological proposal intends to be a useful tool to support managers and decision-makers to understand the dynamics of consumption and then propose effective practices to reduce water and energy uses, as well as providing reference data for comparison with other educational institutions.

Using Statistical Control Charts to Monitor Building Water Consumption: A Case Study on the Replacement of Toilets

This manuscript proposes the usage of Statistical Control Charts (SCC) to monitor water consumption in buildings. The charts were employed to study the impact of replacing toilets, providing visual and statistical feedback to measure the efficiency gain resulting from the replacement of outdated flushing equipment with newer devices. The case study was conducted in a building from a university in the South of Brazil. The building has four restrooms, from which a total of 41,554 readings were collected during a 15-month period using digital water meters. After the toilets were replaced, a reduction averaging 30.22% in water consumption was observed (from 7.51 L/flush/day to 5.24 L/flush/day). Additionally, the control charts were able to pinpoint dates when unique events happened during the water-consumption monitoring process.

Methodology for Estimating Energy and Water Consumption Patterns in University Buildings: Case Study, Federal University of Roraima (UFRR)

Knowing water and energy consumption patterns sets the baseline for understanding their drivers and assessing the perfomance of potential measures to increase efficiency and/or reliability. However, these patterns can vary substantially depending on the building caracteristics, on the building users and use, on the cultural, social, economic, environmental context in which the building is located, among many other factors. This article presents a general methodological framework for characterizing water and energy consumption patterns in buildings based on the evaluation of the proportions of the surface areas of each space type, proposing indicators of water and energy use, by end use per square meter and by space type. Universities, in most cases, represent large water and energy consumers with distintive consumption drivers and patterns which have received limited attention when compared to other types of buildings (e.g., residential). The methodological framework proposed was applied to the buildings of the Paricarana Campus of Federal University of Roraima (UFRR), Brazil, providing one of the few examples in the literature reporting water and energy consumption in university buildings in tropical climates. The findings have shown that teaching rooms and administration rooms are the main source consumers, representing 48% and 49% of the institution's energy and water consumption, respectively. Air conditioning is the biggest energy consumption (63%), while personal use represents 72% of the total water consumption in a building. The toilets represent a large water consumption in a university building (46.40%). Comparing different buildings uses, the central library is the highest source consumption, due to the longest operating time and the highest occupational density. The methodological proposal intends to be a useful tool to support managers and decision-makers to understand the dynamics of consumption and then propose effective practices to reduce water and energy uses, as well as providing reference data for comparison with other educational institutions.

The effect of climate change on domestic Rainwater Harvesting

One of the main strategies that are being applied to improve the efficiency of water consumption in buildings is the use of non-potable water for pavement washing, toilet flushing, irrigation, and others. According to several guidelines, the design and assessment of a Rainwater Harvesting System (RWHS) should be made using recent official records of precipitation. However, there is not an indication whether historical or future projections should be used, leaving space for the designer to choose. This article presents the study of RWHS in southern Europe, namely in Portugal, considering two case studies (a dwelling in Oporto and an apartment in Vila Real). The main goal was to explore the impacts that climate change will have on these systems and, for that purpose, a daily simulation using future rainfall data was performed for both cases considering two scenarios: RCP 4.5 which is more optimistic, and RCP 8.5 which is more pessimistic. The RWHS in Oporto showed a better performance in the future decades, comparing with simulations based on recent decades, for both scenarios. However, the savings will not have a significant variation (less than 5 €/year). In the future, this system will provide around 47 (±2.4) m3 of rainwater per year to the selected non-potable purposes, leading to savings of around 66 (±3.3) €/year. Vila Real case study also revealed a slight improvement of the system's efficiency in the future decades but the results for rainwater collected and used are so similar to the recent ones that it can be concluded that the performance will be sustained. This system will provide around 50 (±2.5) m3 of rainwater per year to the selected non-potable purposes, leading to savings of around 200 (±10.2) €/year. It can be concluded that there will be no significant changes in RWHS performance in the future, in the studied areas.

Diseño de un Sistema de Aprovechamiento de Agua Lluvia bajo criterios de Eficiencia Hídrica en Edificios. Caso de estudio: Edificio de Clases y Laboratorio de Hidráulica de la Facultad de Ingeniería, Ciencias Físicas y Matemática de la Universidad Central

El agua es uno de los recursos naturales indispensables para el desarrollo de la vida. Lamentablemente, la condición de recurso renovable es muy cuestionada. Ecuador es uno de los países de América del Sur con mayor número de fuentes de agua dulce superficiales y subterráneas considerando su área continental. Sin embargo, existen factores influyentes que afectan la disponibilidad del agua dulce como recurso natural y que ponen en riesgo el volumen de estas reservas. El crecimiento exponencial de las poblaciones, el inclemente cambio climático, la falta de leyes y mecanismos de control para el uso responsable de agua potable y en especial, la escasez de cultura sobre la aplicación de prácticas responsables para el uso de agua potable en edificios, hace que este recurso se agote rápidamente. Las cifras estadísticas indican datos alarmantes de Ecuador con respecto a los países de la región, ya que es el mayor consumidor de agua potable con dotaciones que superan los 237 litros/(habitante.día). Esta realidad hace imprescindible que se reduzcan los consumos de agua potable en edificios para mejorar su eficiencia hídrica y convertirlos en proyectos autosustentables sin afectar la sensación de confort en los usuarios. El principal objetivo de este trabajo es el de presentar los resultados obtenidos sobre al análisis de eficiencia hídrica en edificios universitarios de Quito a través de metodologías de cálculo internacionales como la sugerida por la “ANQIP - Associação Nacional para a Qualidade nas Instalações Prediais”, de Portugal. Se concluye que, la instalación de un sistema de aprovechamiento de agua lluvia reducirá considerablemente los consumos de agua potable en un edificio con bajo desempeño hidráulico. El presente estudio se da como tema de investigación de Maestría en el Instituto Politécnico de Leiria y la Universidad Central del Ecuador.

Assessing water, energy and emissions reduction from water conservation measures in buildings: a methodological approach.

Water-energy nexus is a cornerstone in modern societies, with significant impacts at social, environmental, and economic levels. In addition to the issue of water scarcity that several regions of the world already face or are forecasted to face in the near future due to demand increase and availability reduction (e.g. pollution, climate changes), water consumption in buildings entails substantial energy consumption. In most cases, part of this energy is produced from non-renewable sources, encompassing greenhouse gas emissions. The present research effort presents a generic methodology to assess the cascade impact of water efficiency measures in buildings in terms of water, energy and emissions reduction. The methodology is applied to the Mediterranean climate zone context for two different types of non-residential buildings: university buildings and hotels, with very distinct water end use and consumption patterns. Lastly, are performed sensitivity analyses between the proposed methodology and simplified approaches. Is observed that assuming a linear relationship between flow rate and water consumption can lead to overestimations of up to 64% in water savings. Is also explored the relevance of the water consumption and energy mix seasonality typical of climates with marked dry and wet seasons, such as the Mediterranean region. The importance of the seasonality is discussed in terms of the time scale considered to apply the methodology, revealing that adopting a simplified (annual) approach, instead of the proposed approach, can lead to relative differences between - 62 and 233% in the presented case studies.

The influence of different water efficiency ratings of taps and mixers on energy and water consumption in buildings

This paper analyses two different models (methods) used for determination of water consumption in residential buildings. For this purpose, some basic sanitation facilities were implemented in the models as typical household equipment. As there is a big variety of sanitary solutions available, in order to achieve a significant reduction in water consumption, a novel classification of faucets (taps and mixers) is proposed. This classification also allows for the assessment of energy efficiency ratings of sanitary appliances. On the basis of this classification, water savings resulting from the use of faucets with different water efficiency ratios were determined. Depending on the type of faucet, it is possible to achieve more than 50% water savings, as well as a significant reduction in energy demand for heating and pumping water to customers. The paper also discusses the equations used to determine the energy demand for domestic hot-water preparation and its pumping to consumers. The results of the energy consumption calculations for the above-mentioned purposes were determined per person.

Factors influencing water consumption in buildings in southern Brazil

Abstract This study aims to identify the factors influencing water consumption in residential buildings in the city of Joinville, in southern Brazil, through an analysis of socioeconomic variables of users and constructive variables of the building. Data were collected on water consumption, socioeconomic characteristics of the users and constructive characteristics of the buildings, from a sample dataset of 89 buildings including 3171 housing units. Two models describing consumption were identified from a multiple linear regression analysis by means of the stepwise method. The analysis showed there were several variables related to constructive aspects, including the alternative water supply system that were statistically significant in explaining both water consumption in buildings (in m³/month) and per capita water consumption (in liters per person per day). The model explains 87.41% of the water consumption in buildings in Joinville and 79.68% of the per capita consumption. After obtaining the models, water consumption was estimated on eight buildings that were not included in the sample dataset using two equations for water consumption in buildings and per capita water consumption. Leave-one-out cross validation complements the analysis. The two models feature reasonable explanatory and predictive capacity, displaying adjusted and predicted R2 higher than 70%. The obtained results contribute to enhanced understanding of variables related to water consumption in residential buildings in southern Brazil, and may be useful to the authorities in developing sustainable policies.

Water and energy saving potential by adopting pressure-reducing measures in high-rise building: A case analysis

Indoor domestic water demands are increasing rapidly in many cities of China, among the causes, water wastage due to overpressure outflow (OPO) at water distribution points in buildings, especially in high-rise buildings, is a factor that has not gained much attention. Field tests in 23 high-rise public buildings and laboratory tests were conducted to quantitatively evaluate the influence of water pressure on water consumption in buildings. The water-saving potential by adopting pressure reducing measures was theoretically analyzed and verified based on a case study. Results indicated that water consumption is closely related to water pressure and overpressure outflow is a very common culprit of water wastage in high-rise buildings. Pressure management measures, such as branch pipe pressure-reducing valves, can reduce water consumption in buildings and improve the comfortability of use as well. Based on the laboratory pressure–outflow characteristics study of different water appliances, water-saving potential of pressure reducing measures can be theoretically evaluated. Case study demonstrated a theoretical reduction of 19.4% in water consumption by adopting branch pipe pressure-reducing valves, an actual 14,773 m3 water (11.9% reduction) and 15,955 kWh embodied energy was saved in 2015 after the implementation of branch pipe pressure-reducing valves retrofitting measure. Therefore, despite the current measures of adopting high-efficiency water appliances and/or utilization of unconventional water resources in buildings, implementation of pressure management measures is highly recommended in designing water supply system for new high-rise buildings and reconstruction of water supply system in existing high-rise buildings, thereby, promoting water, energy saving, and development of green building. Practical application: Water and energy saving in building is gaining more and more attention, however, water wastage due to overpressure outflow in buildings has not gained much attention. Based on field and laboratory tests, the water and energy saving potential in building water supply system were evaluated theoretically and further verified by a case study. Results indicate that pressure management measures such as branch pipe pressure reducing valves (PRVs) can reduce water and energy consumption in buildings. We strongly suggest that pressure management measures should be implemented in buildings, thereby, promoting water, energy saving, and development of green building.