scholarly journals Centralized hot tap water systems calculation’s specifics

2018 ◽  
Vol 245 ◽  
pp. 07004
Author(s):  
Karina Tumanova ◽  
Anatolijs Borodinecs ◽  
Ivan Dmitriev

Most of the urban housing stock in Latvia as well as in major part of EU cities is apartment multi-storey buildings, most of which have a connection to centralized hot tap water systems. Also, such buildings as dormitories, university campuses, sporting facilities, mostly are connected to the centralized hot tap water systems. The hot tap water systems can have different optional technical solutions, such as recirculation loop, bath towels warmers, etc. All these options affect calculation’s specifics of the systems. The main challenge for designers is to make correct estimation of hydraulic losses, definition of necessary water flow rate and to choose such technical equipment as circulation pumps, balancing valves and circulation water flow. The main parameters directly affecting the sizing of hot tap water system are the number of inhabitants, designed water consumption, consumption uncertainty coefficient, building’s specifics etc. This study is based on the hot water consumption analysis in building were online monitoring system was installed.

2018 ◽  
Vol 245 ◽  
pp. 06011
Author(s):  
Karina Tumanova ◽  
Anatolijs Borodinecs

Most of the urban housing stock in Latvia as well as in major part of EU cities is apartment multi-storey buildings, most of which have a connection to centralized hot tap water systems. Also, such buildings as dormitories, university campuses, sporting facilities, mostly are connected to the centralized hot tap water systems. The hot tap water systems can have different optional technical solutions, such as recirculation loop, bath towels warmers, etc. All these options affect calculation’s specifics of the systems. The main challenge for designers is to make correct estimation of hydraulic losses, definition of necessary water flow rate and to choose such technical equipment as circulation pumps, balancing valves and circulation water flow. The main parameters directly affecting the sizing of hot tap water system are the number of inhabitants, designed water consumption, consumption uncertainty coefficient, building’s specifics etc. This study is based on the hot water consumption analysis in building were online monitoring system was installed.


2018 ◽  
Vol 69 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Dolores Peruč ◽  
Ivana Gobin ◽  
Maja Abram ◽  
Dalibor Broznić ◽  
Tomislav Svalina ◽  
...  

Abstract Mycobacterium avium complex-related diseases are often associated with poorly maintained hot water systems. This calls for the development of new control strategies. The aim of this study was to investigate the activity of essential oils (EOs) from the Mediterranean plants, common juniper, immortelle, sage, lavandin, laurel, and white cedar against Mycobacterium avium ssp. avium, Mycobacterium intracellulare, and Mycobacterium gordonae in culturing broth and freshwater as their most common habitat. To do that, we developed a new method of water microdilution to determine their minimal effective concentrations (MEC). The most active EO was the one from the common juniper with the MEC of 1.6 mg mL-1. Gas chromatography / mass spectrometry the juniper EO identified monoterpenes (70.54 %) and sesquiterpenes (25.9 %) as dominant component groups. The main monoterpene hydrocarbons were α-pinene, sabinene, and β-pinene. The juniper EO significantly reduced the cell viability of M. intracellulare and M. gordonae at MEC, and of M. avium at 2xMEC. Microscopic analysis confirmed its inhibitory effect by revealing significant morphological changes in the cell membrane and cytoplasm of all three bacteria. The mode of action of the juniper EO on the cell membrane was confirmed by a marked leakage of intracellular material. Juniper EO has a great practical potential as a complementary or alternative water disinfectant in hot water systems such as baths, swimming pools, spa pools, hot tubs, or even foot baths/whirlpools.


2018 ◽  
Vol 8 (10) ◽  
pp. 1973 ◽  
Author(s):  
Adnan Ploskić ◽  
Qian Wang ◽  
Sasan Sadrizadeh

The aim of this study was to map the parameters that have the greatest impact on the environmental impact of heating systems usually used in Nordic single-family dwellings. The study focused on mapping the technical requirements for efficient operation of heating systems in a broader context. The results suggest that the ability of a heating system to be operated with a low-temperature water supply depends to a large extent on the heating demand of a building. It was shown that an increase in the water flow rate in hydronic circuits would significantly increase the thermal efficiency from analyzed heating systems. This increase would not increase the pumping power need, nor would it create noise problems in distribution network if the distribution pipes and thermostatic valves were properly selected. However, this increase in water flow rate improved the efficiency of considered closed-loop heat pump. It was further shown that the efficiency of the heat pump could be additionally improved by halving the energy needs for the domestic hot-water and circulators. The main conclusion from this study is that exergy usage, CO2 emission and thereby environmental impact are significantly lower for heating systems that are operated with small temperature drops.


Author(s):  
Gang Wang ◽  
Mingsheng Liu ◽  
David Claridge

Heating and cooling energy consumption measurements are critical for operations, controls, and fault detection and diagnosis of heating, ventilation and air conditioning (HVAC) systems. Generally water flow has to be measured in order to determine energy consumption in either chilled water systems or hot water systems. Economical and accurate water flow measurements are essential to develop energy meters. Since pump performance relates actual pump water flow to pump head and power, theoretically water flow through a pump can be determined by other pump performance characteristics, such as pump head and motor power. This paper presents the theoretical model of pump flow stations based on pump head and motor power, and the experiments and results of a cooling energy meter using a pump flow station developed on the chilled water system at a facility.


2019 ◽  
Author(s):  
MJ Booysen

Electric water heaters are responsible for a large portion of electricity consumption and water usage in the domestic sector. Smart water heaters alleviate the strain on the electricity supply grid and reduce water consumption through behavioural change, but the installation of in-line flow meters is inconvenient and expensive. A non-invasive water flow meter is proposed as an alternative. Non-invasive flow measurement is more common for high flow rates in the industrial sector than for domestic applications. Various non-invasive water measurement methods are investigated in the context of domestic hot water, and a combination of thermal- and vibration-sensing is proposed. The proposed solution uses inexpensive, easily installable, non-invasive sensors and a novel algorithm to provide the same flow measurement accuracy as existing in-line meters. The algorithm detects the beginning and end of water consumption events with an accuracy of 95.6%. Quantitative flow rate estimation was possible for flow rates greater than 5 L min⁻¹ with an accuracy of 89%, while volumetric usage estimation had an accuracy of more than 93%. The algorithm limitations were applied to field data, revealing that water consumption could be detected with an error of less than 12% within the limitations of the proposed algorithm. The paper presents a successful proof of concept for a non-invasive alternative to domestic hot water flow rate measurement.


2011 ◽  
Vol 1 (2) ◽  
Author(s):  
I Made Rasta

Refrigerant in refrigeration machines will absorb heat from a room space and released the heat to the environment. The heat balancing in the system is heat released from condenser equal with heat absorbed from room space added by the heat equivalent from compressor work. Based on this heat cycle, the writer try to conduct research on using this heat rejection from condenser to heating tap water, focusing on water flow rate increased from 0.5 liter/min to 2.5 liter/min. From experiment and analysis result obtained that the maximum heat water temperature which can be reached is 47.5°C in 0.5 liter/min, with the equipment specifications are 2 HP- split air conditioning and the tank volume is 75 liters. The additional result is heating water temperature is fallen when the water flow rate is increased.


Author(s):  
Anand. P ◽  
Devipreetha. K ◽  
Haripriya. R

Managing water consumption is important for life preservation. Knowing water consumption at homes can have a great impact on water saving. There is a global water crisis due to increasing population growth, climate change, increasing consumption. Giving a report about the state of the planet’s water, especially in developing countries, the report describes the outlook for future generations as worries. To visually check water taps in the house consumes time and requires a family member to be at the house. To remotely do so, we propose a system that monitors, alerts the user and allows the user to control the water flow through taps whenever there is an unusual reading of the water usage at home. The Water Flow Monitoring and Controlling System is an android- based mobile application. It is equipped with external hardware to sense a tap’s water flow rate and control which means turning on or off the water supply line whenever necessary. Registered users can login and view their house’s current water flowage from the mobile application. The external hardware updates the water flow rate at every specified time to a database through the Internet connection. If the users decide to turn on or off the water supply taps at their homes, it can be done through the on or off button provided in the mobile application. A user’s on or off instruction is set within the database. The hardware receives this instruction and performs the desired action.


Author(s):  
Le Minh Nhut ◽  
Tran Quang Danh

Hot water is an important factor in domestic life and industrial development. Today, the heat pump is used to produce hot water more and more popular because it has many advantages of saving energy compared to the method of producing hot water by the hot water electric heater. The main aim of this study is to evaluate of the coefficient of performance (COP) of the small hot water heat pump using refrigeration R410A and R32. The capacity of both hot water heat pump is similar, one using new refrigerant R32 and other using refrigerant R410A. These heat pumps were designed and installed at the Ho Chi Minh City University of Technology and Education to evaluate the COP for the purpose of application the new refrigerant R32 for hot water heat pump. The compressor capacity is 1 Hp, the volume of hot water storage tank is of 100 liters and is insulated with thickness of 30 mm to reduce the heat loss to invironment, the required hot water temperature at the outlet of condenser is 50 oC, and the amount of required hot water is 75 liters per batch and is controlled by float valve. The experimental results indicate that the COP of the heat pump using the new refrigerant R32 is higher than heat pump using refrigerant R410A from 9% to 15% when the experimental conditions such as ambient temperature, initial water flow rate through the condenser and the required temperature of hot water were the same. In addition, the effect of the ambient temperature, initial water temperature and water flow rate were also evaluated.


2004 ◽  
Vol 70 (3) ◽  
pp. 1651-1657 ◽  
Author(s):  
Helena Aurell ◽  
Philippe Catala ◽  
Pierre Farge ◽  
France Wallet ◽  
Matthieu Le Brun ◽  
...  

ABSTRACT A new method for the rapid and sensitive detection of Legionella pneumophila in hot water systems has been developed. The method is based on an IF assay combined with detection by solid-phase cytometry. This method allowed the enumeration of L. pneumophila serogroup 1 and L. pneumophila serogroups 2 to 6, 8 to 10, and 12 to 15 in tap water samples within 3 to 4 h. The sensitivity of the method was between 10 and 100 bacteria per liter and was principally limited by the filtration capacity of membranes. The specificity of the antibody was evaluated against 15 non-Legionella strains, and no cross-reactivity was observed. When the method was applied to natural waters, direct counts of L. pneumophila were compared with the number of CFU obtained by the standard culture method. Direct counts were always higher than culturable counts, and the ratio between the two methods ranged from 1.4 to 325. Solid-phase cytometry offers a fast and sensitive alternative to the culture method for L. pneumophila screening in hot water systems.


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