Model of a System-Wide Domestic Hot-Water Distribution System in a Multi-Resident High-Rise Building

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Marin Vratonjic ◽  
Ali Rahmatmand ◽  
Feras Marish ◽  
Pierre Sullivan
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Cold Water ◽  
Field Measurements ◽  
Hot Water ◽  
Domestic Hot Water ◽  
High Rise ◽  
Advanced Analysis ◽  
Component Failures ◽  
Story Building

Abstract To reduce the environmental impact and cost, energy and water consumption of multi-resident buildings should be improved while ensuring resident comfort. Inefficient mixing of hot and cold-water streams and a non-optimal domestic hot-water (DHW) distribution system design can cause higher energy consumption, component failures, and dissatisfied residents. An OpenModelica (OM) system-wide model of a 14-story building consisting of a controlled-loop injection (CLI) device and a DHW distribution system is presented. The OM results are validated against field measurements at discreet locations within a single-zone closed-loop circuit to ensure the validity of time-varying temperature and flowrate. The study demonstrates that OM is a useful engineering tool to model single and multi-zone high-rise buildings that allows advanced analysis, including system-wide optimization, advanced on-demand controls, and energy and water-usage efficiencies.

Determinants of Legionella pneumophila Contamination of Water Distribution Systems: 15-Hospital Prospective Study

1987 ◽  
Vol 8 (9) ◽  
pp. 357-363 ◽  
Author(s):  
Richard M. Vickers ◽  
Victor L. Yu ◽  
S. Sue Hanna ◽  
Paul Muraca ◽  
Warren Diven ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Cold Water ◽  
Physicochemical Characteristics ◽  
Hot Water ◽  
Environmental Study ◽  
Water Tank ◽  
One Year

AbstractWe conducted a prospective environmental study for Legionella pneumophila in 15 hospitals in Pennsylvania. Hot water tanks, cold water sites, faucets, and show-erheads were surveyed four times over a one-year period. Sixty percent (9/15) of hospitals surveyed were contaminated with L pneumophila. Although contamination could not be linked to a specific municipal water supplier, most of the contaminated supplies came from rivers. Parameters found to be significantly associated with contamination included elevated hot water temperature, vertical configuration of the hot water tank, older tanks, and elevated calcium and magnesium concentrations of the water (P < 0.05). This study suggests that L pneumophila contamination could be predicted based on design of the distribution system, as well as physicochemical characteristics of the water.

scholarly journals Analysis of building plumbing system flushing practices and communications

2019 ◽  
Vol 17 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Lisa Ragain ◽  
Sheldon Masters ◽  
Timothy A. Bartrand ◽  
Jennifer L. Clancy ◽  
Andrew J. Whelton
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Grade Level ◽  
Water Distribution ◽  
Cold Water ◽  
Expert Elicitation ◽  
Hot Water ◽  
Single Family ◽  
Point Of Entry ◽  
12Th Grade

Abstract Drinking water distribution system contamination incidents can prompt public agencies and drinking water utilities to issue do-not-drink and do-not-use advisories. After the contaminant is cleared from distribution mains, consumers are often directed to flush their plumbing. However, little validated guidance and few evaluated communications strategies are available on using flushing to decontaminate building water systems. Additionally, limited data support the effectiveness of current practices and recommendations. In this study, expert elicitation was used to assess existing flushing guidance and develop validated flushing guidance and communications for single-family residences. The resulting guidance recommends progressively opening all cold-water taps from the closest to point of entry to the furthest and allowing the water to run for at least 20 minutes. Hot-water taps should be opened progressively and run for at least 75 minutes. The guidance language and format conformed to grade-level and readability scores within recommended health communication ranges. The readability of eight other flushing guidance documents was also evaluated for contamination incidents from 2008–2015. Seven were written at a 10th–12th grade level, above the 6th–7th grade level recommended for health communications.

Isolation of Legionella pneumophila from the Cold Water of Hospital Ice Machines: Implications for Origin and Transmission of the Organism

1985 ◽  
Vol 6 (4) ◽  
pp. 141-146 ◽  
Author(s):  
Janet E. Stout ◽  
Victor L. Yu ◽  
Paul Muraca
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Cold Water ◽  
Water System ◽  
Primary Source ◽  
Hot Water ◽  
Hospital Environment ◽  
Water Storage Tank

AbstractAlthough the mode of transmission of L. pneumophila is as yet unclear, the hot water distribution system has been shown to be the reservoir for Legionella within the hospital environment. In this report we identify a previously unrecognized reservoir for L. pneumophila within the hospital environment, ie, the cold water dispensers of hospital ice machines. The cold water dispensers of 14 ice machines were cultured monthly over a 1-year period. Positive cultures were obtained from 8 of 14 dispensers, yielding from 1 to 300 CFU/plate. We were able to link the positivity of these cold water sites to the incoming cold water supply by recovering L. pneumophila from the cold water storage tank, which is directly supplied by the incoming municipal water line. This was accomplished by a novel enrichment experiment designed to duplicate the conditions (temperature, sediment, stagnation, and continuous seeding) of the hot water system. Our data indicate that significant contamination of cold water outlets with L. pneumophila can occur. Although no epidemiologic link to disease was made, the fact that the primary source of a patient's drinking water is from the ice machines warrants further investigation of these water sources as possible reservoirs.

scholarly journals An Analysis Model for Domestic Hot Water Distribution Systems

2011 ◽  
Author(s):  
Jeff Maguire ◽  
Xia Fang ◽  
Moncef Krarti
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Simulation Software ◽  
Hot Water ◽  
Water Heater ◽  
Domestic Hot Water ◽  
Study Results

A thermal model was developed to estimate the energy losses from prototypical domestic hot water (DHW) distribution systems for homes. The developed model, using the TRNSYS simulation software, allows researchers and designers to better evaluate the performance of hot water distribution systems in homes. Modeling results were compared with past experimental study results and showed good agreement. The model was also compared with existing domestic hot water distribution system modeling software HWSIM for verification. The developed model has several capabilities that are not available in HWSIM, including the ability to integrate any new or existing types of water heater systems, the ability to handle several simultaneous draws to different end uses, and the ability to handle unique annual draw profiles instead of weekly draw profiles. It also allows for draw profiles and ambient conditions to be considered using any time resolution. To demonstrate the abilities of this new model, a series of sensitivity analyses were performed using a benchmark domestic hot water distribution system. The effects of adding insulation to the domestic hot water distribution system of homes with a gas water heater and a solar water heater were also examined.

scholarly journals Hot Water Distribution System Program Documentation and Comparison to Experimental Data

2007 ◽  
Author(s):  
Evelyn Baskin ◽  
William G Craddick ◽  
Roberto Lenarduzzi ◽  
Robert L Wendt ◽  
Professor Keith A. Woodbury
Keyword(s):  
Experimental Data ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Hot Water ◽  
System Program

scholarly journals THE ANALYSIS OF WATER SPEED INFLUENCE IN HOT-WATER DISTRIBUTION SYSTEM ON THE AMOUNT OF HEAT LOSS

2021 ◽  
Vol 2021 (1) ◽  
pp. 23-28
Author(s):  
Peter Kapalo ◽  
◽  
Khrystyna Kozak ◽  
Khrystyna Myroniuk ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Ventilation System ◽  
Hot Water ◽  
Graphical Form ◽  
Hot Water Supply System

One of the main tasks around the world is to reduce energy consumption with constant consumer comfort. The hot water supply system uses a significant part of thermal energy and requires no less attention than the heating or ventilation system. The amount of heat loss from hot water distribution systems is of great importance for the energy consumption of buildings. In winter, part of this heat is used for space heating, in summer they are unused and is considered as lost heat. For this reason, this paper considers the influence of water velocity in the pipe, pipe size, and water temperature on the total heat losses in the insulated hot-water distribution system. The data are presented in tabular and graphical form. A graph of the dependence of the amount of heat loss on the temperature and velocity of hot water is obtained.

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