Water Supply Systems In Buildings Research Articles

A methodology to simulate peak water demand for water supply systems using semi-direct methods: A case study for a residential building in Mexico

Historically, approaches for determining peak water demand in buildings have been based on probabilistic methods. Extensive research has shown that these methods lack accuracy because of the human factor in the probability of use. Inaccuracy in the calculation of peak water demand is the main cause of oversized water supply systems in buildings. This has led to unfavorable effects such as: 1) increasing the building carbon footprint due to the use of more construction materials, and 2) engendering health hazards due to the stagnation of water causing microbial growing. This paper presents a step-by-step methodology that serves to calculate the peak water demand by simulating the use of plumbing fixtures based on data obtained from standardized flowrate. With the implementation of the methodology, the peak water demand estimated was 2.6 times lower in comparison to traditional methods. The main conclusion drawn from the research is the potential of the methodology to easily simulated peak water demand in residential buildings in the short term. Thus, it reveals a hotspot for peak water demand calculation and can serve as routes for future research.

Occurrence of Legionella sp. bacteria in hot water systems in hospitals and nursing homes in the Świętokrzyskie Province of south-eastern Poland.

The occurrence of bacteria of the genus Legionella sp. in hot water supply systems in buildings is a real threat to human health, especially for patients in hospitals and residents of nursing homes. The aim of the study was determination of the degree of colonization of hot water systems in hospitals and nursing homes in the Świętokrzyskie Province in south-east Poland. Between 2014 - 2018, samples were collected from hot water systems in 30 hospitals and 32 nursing homes in order to determine the degree of contamination. 631 samples collected of the bacteria Legionella sp were analyzed. Excessive contamination (≥ 100CFU/100 ml) with the bacteria Legionella sp. was detected in 12.12% (n=71) of samples. Contamination was significantly more frequently detected in samples from hot water systems in nursing homes, compared to hospitals (16.48% vs. 10.37%). Above-standard contamination of hot water systems with Legionella sp. bacteria occurred in 34.43% of the facilities, and was more frequent in hospitals (41.38%) than in the nursing homes (28.13%). In 21.3% of the facilities, contamination was detected many times during the study period. Excessive contamination of hot water systems with Legionella sp. bacteria in the examined facilities was a common phenomenon. The presence of the pathogen in the installations of these facilities may constitute a considerable health hazard for patients and residents.

FIS-based approach to estimate probable flows for sizing pipes in building water supply systems

ABSTRACT The paper presents Fuzzy Inference System (FIS) -based approach to estimating probable flows for sizing building water supply pipes. Instead of calculating the design flow by estimating the number of fixtures operating simultaneously using probabilistic or deterministic approach utilizing a large amount of high-resolution field data, the proposed methodology uses Fuzzy logic to estimate demand characteristics of fixtures, unlike conventional fixture unit method. The developed methodology is based on FISs derived from users’ socio-demographic characteristics, their diurnal activities and water use habits. A MATLAB program was developed to estimate the probable flows through the pipe using inputs-type of accommodation, connected fixture types and fixture flow rates. An imaginary 7-storey residential building with a gravity tank system was considered for pipe sizing. The design flows obtained by the proposed methodology were 50–70% of the those produced by the fixture unit approach leading to smaller pipe sizes.

User-based fuzzy end-use modeling of indoor urban residential water demand

Stochastic models for estimating residential water demand use high-resolution field data consuming large costs and significant time. An attempt for the accurate estimation of water demand may result in its complex analytical model due to numerous factors affecting the water use event. Moreover, as the water supply system is always subjected to variations in demand, the accuracy of water demand estimation in its design can be side-lined. The water demand in residential buildings is mainly governed by the users’ characteristics and their daily schedule. In this view, the use of Fuzzy Logic can be advantageous to model the uncertainty in water demands. The presented study attempts to provide a methodology to estimate urban indoor residential water demand with the help of user-based end-use models in the absence of field data and generate various possible water demand patterns of fixtures. Usergroups were created for assuming spatial variations in water demand. Fuzzy Logic was used to develop the end-use models using data on urban users’ characteristics, their diurnal activities, and water use habits to estimate the demand characteristics of fixtures. The model may also facilitate the computation of pipe sizing in building water supply systems.

Environmental evaluation of pump replacement period in water supply systems of buildings

Cost analysis of facility replacement is the common method used in building services facility management nowadays, however, replacement evaluation from the environmental aspect still lacks in literature. This study is the first trial to introduce the environmental evaluation, life cycle assessment technique is adopted, into the replacement period justification of building services facilities, taking water supply pump in buildings as an example. An environmental evaluation model of water supply pump replacement is proposed in this study to minimize the total environmental impact (i.e. energy consumption) of the water supply system, which compares the extra operational energy expenditure in the long-term operation to the pump embodied energy. The literature review is used to obtain the energy intensity data, of mining, metal production, and metal casting, for the determination of pump embodied energy. The results demonstrate that for common pump motor ratings of 1.1–5 kW in water supply systems of buildings, with annual efficiency drop and pump energy intensity that ranges from 0.012 to 0.028 and 18.2–177.6 GJ/t iron and steel respectively, a longer pump replacement period is noticed at the greater energy intensity of pump (the maximum difference of the replacement period can be about 10 years). Besides, higher annual efficiency drop justifies a shorter pump replacement period. It was found that the replacement periods of smaller pumps are more sensitive to the pump energy intensity and annual efficiency drop. Moreover, it was also shown that for pumps with the maximum embodied energy intensity (i.e. 177.6 GJ/t iron and steel), for example, the pump material is stainless steel, the pump replacement periods evaluated on the environmental and economic grounds are comparable. The study results provide an alternative solution of pump replacement period for water supply systems in buildings based on the life cycle environmental assessment of water pump.

Residential water demand modelling and hydraulic reliability in design of building water supply systems: a review

Abstract The building water supply system is a fundamental unit in water supply systems as it is directly associated with end users. However, the studies available on its efficient design are limited. Water demand estimation continues to be an important issue in water supply systems' design because of its multifaceted nature. Hunter's curve, or Fixture Unit method, is widely used for estimating the load on plumbing. Regardless of its popularity, it has a few drawbacks and is arbitrarily modified in some plumbing codes. Fixture-use probability, a basic entity in the Fixture Unit and some other methods, is a difficult parameter to estimate. Commonly, high-resolution field data is used for stochastic modelling of residential water demand which may not be always available. The paper reviews important residential water demand models in view of their applicability in building water supply system design. The irregular nature of water demand in buildings is due to uncertainty in water-use behaviour of users at fixture level. Use of soft-computing techniques can provide an advantage over the other methods in modelling such behaviour. The paper also discusses reliability of building water supply systems and applicability of some common indices for estimating reliability of building water supply systems.

Microbial diversity in full-scale water supply systems through sequencing technology: a review.

The prevalence of microorganisms in full-scale water supply systems raises concerns about their pathogenicity and threats to public health. Clean tap water is essential for public health safety. The conditions of the water treatment process from the source water to tap water, including source water quality, water treatment processes, the drinking water distribution system (DWDS), and building water supply systems (BWSSs) in buildings, greatly influence the bacterial community in tap water. Given the importance of drinking water biosafety, the study of microbial diversity from source water to tap water is essential. With the development of molecular biology methods and bioinformatics in recent years, sequencing technology has been applied to study bacterial communities in full-scale water supply systems. In this paper, changes in the bacterial community and the influence of each treatment stage on microbial diversity in full-scale water supply systems are classified and analyzed. Microbial traceability analysis and control are discussed, and suggestions for future drinking water biosafety research and its prospects are proposed.

The application of life cycle assessment for the optimization of pipe materials of building water supply and drainage system

The selection of pipe of the building water supply and drainage system in buildings is important for energy conservation. In the past, the building designer mainly considered the use performance and one-time cost of pipes in building water supply and drainage system but ignored the differences in resources, energy consumption and pollutant emissions in the whole life cycle of different pipes. This paper combines the life cycle assessment with the analytic hierarchy process to analyze the energy consumption, resource consumption and its impact on the environment of different pipes in the building water supply and drainage system. The results showed that the energy consumption of PVC-U pipe in the building water supply system could be reduced by 86 % and 91 % compared with that of galvanized steel pipe and copper pipe, and the reduction value in the drainage system was about 86 %.Galvanized steel pipes, copper pipes, and cast iron pipes are approximately 7.3 to 11.3 times larger than PVC-U pipes in a single indicator for comprehensive environmental impact assessment. This study shows that replacing other metal pipes with PVC-U can significantly reduce the environmental impact, which also implies the importance of life cycle assessment in the design of building pipes.

Main water quality safeguard of healthy building

<p indent="0mm">Human beings cannot live without water. As the living space of human beings, architecture cannot do without water. The water quality safeguard of healthy buildings includes water quality safeguard for municipal water supply and secondary water supply systems. Compared with municipal water supply system, water quality assurance of secondary water supply system is often ignored in people’s traditional concept, while the latter is more likely to cause water quality deterioration. Healthy building is a building that can provide healthier environment, facilities and services for building users and promote their physical and mental health. The water supply system of a healthy building should be able to provide safe and high quality water to building users. Water quality safeguard technology is the key support to achieve the above goals. This paper mainly analyzes and introduces the water quality safeguard for secondary water supply system of healthy buildings. The water quality guarantee measures that can be adopted in the system setting, operation and maintenance of healthy buildings are summarized into three main aspects: Prevention of water quality deterioration, water quality monitoring and water treatment. Prevention of water quality deterioration is the first line of defense to ensure healthy building water quality. Water quality deterioration is usually caused by two factors: Microbial breeding in the water and pollution in the water supply. Problems such as long storage time, inadequate cleaning and maintenance of storage facilities, improper selection of water pipes for transmission and distribution, and insufficient water supply temperature of centralized domestic hot water system will lead to the breeding of bacteria and other microorganisms in water. Problems such as improper installation of water storage facilities and wrong connection of pipes in quality water supply system will lead to water pollution. The prevention of water quality deterioration of secondary water supply system mainly involves water storage facilities, water supply pipes and central domestic hot water system. The water quality online monitoring system can detect water quality indicators in real time through the configuration of online testing equipment, and then upload the monitoring data to the remote data management platform, and finally analyze the monitoring data and alarm the accident by the data management platform. Online monitoring of water quality can help managers to know the abnormal changes of water quality in time, so as to take effective measures to avoid the increase of water quality deterioration accidents. The main technologies and management measures involved in water quality monitoring include water quality online monitoring, regular testing and monitoring results publicity. Water treatment is the ultimate defense of healthy building water quality. Healthy building water supply system can adopt water treatment technology to ensure the safety, improvement and improvement of water quality. Water treatment technologies that can be used in healthy buildings generally include disinfection, filtration, softening and other major water treatment technologies and direct drinking water treatment systems. Different buildings can make economic and technological comparison according to the user’s demand for water quality, and finally choose a reasonable one or a variety of comprehensive water treatment technology. The aim of this paper is to provide suggestions and broaden ideas for the water quality safeguard of healthy buildings, and help health building users understand health building water quality safeguard.

建物内給水システムにおける給水温の予測法 （第2報）大学施設の受水槽水温の計測値と計算値の比較

建物内給水システムにおける給水温の予測法 （第2報）大学施設の受水槽水温の計測値と計算値の比較

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.

PECULIARITIES OF DESIGN AND OPERATION OF WATER SUPPLY SYSTEMS OF HIGH-RISE BUILDINGS

In this article the problem of design and operation of water supply systems for high-rise buildings in Russia, including in Togliatt i, is considered. The system of water supply of highrise buildings in modern design conditions is substantiated. It is noted that the existing design methods are based on the norms of the last century, without taking into account modern developments in the fi eld of sanitary equipment and the requirements for resource saving. It is substantiated that in order to above-mentioned problems solution it is necessary to study the development trends of the regulatory base in the fi eld of high-rise construction; to determine the operational features of high-rise building water supply systems; to reveal factors aff ecting resource conservation in the water supply system of high-rise buildings; to study effi ciency of pumping units operation and peculiarities of their regulation; to evaluate the water-saving eff ect from the use of modern water-fi ttings.

The impact of domestic rainwater harvesting systems in storm water runoff mitigation at the urban block scale

In the framework of storm water management, Domestic Rainwater Harvesting (DRWH) systems are recently recognized as source control solutions according to LID principles. In order to assess the impact of these systems in storm water runoff control, a simple methodological approach is proposed. The hydrologic-hydraulic modelling is undertaken using EPA SWMM; the DRWH is implemented in the model by using a storage unit linked to the building water supply system and to the drainage network. The proposed methodology has been implemented for a residential urban block located in Genoa (Italy). Continuous simulations are performed by using the high-resolution rainfall data series for the ‘‘do nothing’’ and DRWH scenarios. The latter includes the installation of a DRWH system for each building of the urban block. Referring to the test site, the peak and volume reduction rate evaluated for the 2125 rainfall events are respectively equal to 33 and 26 percent, on average (with maximum values of 65 percent for peak and 51 percent for volume). In general, the adopted methodology indicates that the hydrologic performance of the storm water drainage network equipped with DRWH systems is noticeable even for the design storm event (T = 10 years) and the rainfall depth seems to affect the hydrologic performance at least when the total depth exceeds 20 mm.

Survey-Based Analysis of Water Consumption Law in High-Rise Public Buildings and Water-Saving Performance of Pressure-Reducing Measures

Facing the contradiction of water scarcity and water wastage in most cities of China, this study aims at probing into the factors influencing water-use efficiency and assessing water-saving potential by adopting pressure control measures based on field survey conducted in 23 high-rise buildings in Suqian, China and laboratory tests. Results showed that per capita water consumption (PCWC) exceeding water consumption norms is common in these buildings. The hourly water consumption variation law is quite different among different types of buildings. These differences should be considered in designing building water supply systems to lower water and energy consumption. On the basis of correlation analysis, the order of factors influencing the PCWC follows average tap water pressure, percapita building area, and building age, suggesting pressure management in high-rise buildings is a key water-saving measure. Field tests of outflow characteristics under different water pressures indicated that over-pressure outflow (OPO) is a common cause of water wastage in buildings, however, no branch pipe pressure control measures were found in all the surveyed buildings. Laboratory tests showed that branch pipe pressure-reducing measures can lower water consumption and improve the comfortability of use as well. Therefore, in addition to applying high efficiency water-saving devices, we strongly recommend that branch pipe pressure-reducing measures should be strictly implemented in designing new building water supply systems and reconstruction of existing old building water supply systems, thereby, promoting water, energy saving and development of green building.

Energy Resources Consumption Minimization in Housing Construction

The article deals with the energy savings analysis during operation of buildings, provides the heat balance of residential premises, considers options for energy-efficient solutions for hot water supply systems in buildings. As technical facilities that allow the use of secondary heat sources and solar energy, there are also considered the systems with heat recovery of “gray” wastewater, heat pumps, solar collectors and photoelectric converters.

Optimizing water supply pump replacement in buildings of Hong Kong

This paper investigates the pump efficiency of existing water supply systems in high-rise buildings in Hong Kong and provides economic justification for pump replacement by comparing the long-term energy cost savings to the initial installation costs. Energy consumptions of water supply pumps were measured with the pump efficiencies determined from the water consumptions of 20 water supply systems in buildings. The study results indicate that for typical pump motor ratings that range from 1 to 40 kW in a high-rise water system, with new pump efficiencies and annual pump efficiency drops that range from 0.68 to 0.74 and 0.012 to 0.028 respectively, a shorter replacement period can be justified on energy cost grounds for larger pumps with greater annual efficiency drops. Practical application: This paper exhibits numerical solutions of replacement period justified on energy cost grounds for typical pump motor ratings that range from 1 to 40 kW in a high-rise water system, with new pump efficiencies and annual pump efficiency drops that range from 0.68 to 0.74 and 0.012 to 0.028, respectively.

Practical guidelines for a reliability-based design of building water supply systems

Certain complaints about building water supply systems (BWSSs) arise from their oversizing or undersizing. It is essential to improve their efficiency by minimizing their cost and maximizing the benefit accrued from them. This work introduces practical guidelines for BWSSs design, which deal not only with the cost optimization but also with water availability during high demands. A head-dependent analysis function, which takes into consideration the pressure dependency of nodal outflows, is presented. A resilience index, minimum surplus head, and failure index are used to express the capability of BWSSs to overcome peak demand conditions. The proposed approach was applied on a direct BWSS within three identical residential floors at different levels. It was found that, the internal pipes are preferable to have the same diameter while the main riser for each floor must be increased as the height of the floor increases.

Pump Efficiency of Water Supply Systems in Buildings of Hong Kong

Energy efficiency of water supply systems in high-rise residential buildings becomes a concern for sustainable development nowadays. It has been reported the energy efficiency for high-rise water supply systems is below 25% and more than 75% input energy is ‘lost’, about half of the energy loss attributes to water pumps. Water pump operating at low efficiency is highly undesired. This paper investigates the in-use water pump efficiency for water supply systems in high-rise buildings of Hong Kong. The pumping efficiencies evaluated from a survey of 20 high-rise water supply systems were presented as a function of installation time. Expressions of in-use pump efficiency were proposed and pump replacement time was suggested. Better performed pumps got longer suggested service period and poorer performed ones got shorter payback periods. More frequent replacement was suggested for larger pumps and the payback period was generally shorter.

Series-Parallel Combined Constant Pressure Water Supply Pipeline Design of High-Rise Building

The existing parallel type pressurized water supply pipeline of high-rise buildings has been improved to build energy-saving high-rise building water supply systems. Series-parallel combined constant pressure water supply pipeline is designed. Antipollution high water tank is reasonably installed above the middle area of the building to supply water for the middle area high water tank and supply pressurized water by water pumps for high-rise district. And PLC control system is designed to control the work efficiency of the water pumps according to the sensor feedback information. Verified by calculation and simulation, series-parallel combined constant pressure water supply pipeline is better than parallel water supply pipes in saving the energy which is about the middle-Hybrid phase consumption of the latter. PLC control is simulated and the results show that PLC can effectively control the water supply system to ensure stable water pressure so as to save energy.

Henry Darcy in his own words

A recently published English translation of the Les Fontaines publiques de la ville de Dijon 1 provides access to Henry Darcy's own words on the importance of water for public sanitation and on questions engineers face in building water supply systems. Written near the end of Darcy's life, the book is a compendium of the water knowledge he had gained over decades and his opinions on these topics reveal his personality. In the 1840s, Darcy built a water supply system to provide water to 120 street fountains for domestic purposes, street washing and firefighting. Surrounded by poverty, Darcy insisted on free water for the poor and on sharing the spring water with towns located along the aqueduct that brought it to Dijon. In the preface to the book, Darcy introduces his experiment on water flow through sand with the modest words “to my knowledge, no one has experimentally demonstrated the laws of water flow through sand.” This article provides a sampling of the book's insights into the personality of this remarkable man.