Sustainable and energy-efficient domestic hot water systems: A review

Pomianowski, Michal Zbigniew; Johra, Hicham; Marszal-Pomianowska, Anna; Zhang, Chen

doi:10.1016/j.rser.2020.109900

Cited by 113 publications

(48 citation statements)

References 73 publications

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“…As buildings are becoming more energy efficient, the share of DHW energy is increasing. However, so far, there has been relatively limited efforts in the field of energy-efficient DHW [2].…”

Section: Flexibility Potential Of Dhw Systemsmentioning

confidence: 99%

“…The flexibility capacity of DHW systems is largely based on the volume of the storage tank [1]. When storing DHW there are heat losses; [2] found ranges from 2% to 36% heat losses in the storage tanks depending on the system solution. The VarmtVann2030 project found annual heat loss values in the range of 4 kWh per litre stored [4].…”

Section: Flexibility Potential Of Dhw Systemsmentioning

confidence: 99%

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Energy flexibility potential of domestic hot water systems in apartment buildings

et al. 2021

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Domestic Hot Water (DHW) storage tanks are identified as a main source of flexible energy use in buildings. As a basis for energy management in apartment buildings, this paper describes the aggregated DHW use in a case building, and analyses the potential for DHW energy flexibility by simulating different control options. The case study for the work is an apartment building in Oslo with 56 apartments and a shared DHW system. Energy measurements are available for consumed hot water, hot water circulation, and energy supplied to the DHW tanks. The measurements are presented with minute, hourly and daily values. Aggregated daily energy use for the consumed hot water is in average 362 kWh, while the energy supplied is 555 kWh. The potential for energy flexibility is analysed for a base case and for four different rule-based control options: Power limitation, Spot price savings, Flexibility sale and Solar energy. Economic consequences of the control options are compared. With the Norwegian tariff structure, maximum hourly power use has the main impact on the cost. Control systems that aim to reduce the maximum power use may be combined with spot price savings or to offer end-user flexibility services to the grid.

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Section: Flexibility Potential Of Dhw Systemsmentioning

confidence: 99%

Section: Flexibility Potential Of Dhw Systemsmentioning

confidence: 99%

Energy flexibility potential of domestic hot water systems in apartment buildings

et al. 2021

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“…7) Domestic hot water: DHW system design [19]. 8) Ligthing: physics of light, natural lighting and artificial lighting systems [13].…”

Section: Identification Of Concepts Related To Each Nearly Zero Energy Building Skillmentioning

confidence: 99%

Engineering Skills and Knowledge Related to nZEB Construction

Munshi¹,

Marina²

2021

Proceedings of the 6th UPI International Conference on TVET 2020 (TVET 2020)

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The buildings sector is the largest energydemanding and polluting sector in the global economy. The implementation of nearly Zero Energy Buildings contributes to reducing energy use and climate change. To support this construction there is a need for educating professionals with the required skills and competencies on energy-efficient buildings. This paper reports on the necessary knowledge to be acquired by engineers to deliver nZEB projects. Here, we identify the entire set of nZEB features described by the European Commission through the EPBD and highlight the concepts to be imparted for each of these technical features. We also present a methodology for analysing nZEB content in university curriculum and contributes to the continuing sustainability education discourse. Thus, it is hoped this study will inform education planners and researchers for gaining knowledge on nZEB teaching.

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“…They note the importance of draw-off profiles and appropriate time intervals. Pomianowski et al (2020), reviewing the current state of work on improving the energy performance of domestic water heaters, highlight the importance of measured energy data and spatial distribution of water usage for optimisation, and they note that advanced control strategies can cleverly adjust heating systems to decrease energy loss, increase user comfort and minimise Legionella risks. Legionella bacteria can flourish in water heaters at lower water temperatures.…”

Section: Introductionmentioning

confidence: 99%

Optimal schedule and temperature control of stratified water heaters

Engelbrecht

Ritchie

Booysen

2021

Energy for Sustainable Development

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Water heating is a major component of domestic electrical energy usage, in some countries contributing to 25 % of the residential sector energy consumption. Demand response strategies can reduce the time-of-use costs and overall electrical energy consumption. We present a method to reduce the electrical energy usage itself. Our novel heating schedule control minimises the electric water heater's energy usage without compromising user convenience. We achieve optimal control, while taking into account the natural temperature stratification of the water in the tank, using the A* search algorithm. Since previous research assumes a one-node thermal model, we also assess the effect of excluding stratification. We match three optimal control strategies to a baseline: the standard "always on" thermostat control. The first two strategies respectively match the temperature and the energy of the hot water supplied by the water heater. The third, a variation on the second, includes a method of preventing the growth of Legionella bacteria. We tested 77 water heaters over four weeks, a week for each season, and all three strategies saved energy. The median savings were 6.3 % for temperature-matching, 21.9 % for energy-matching and 16.2 % for energy-matching with Legionella prevention. Taking stratification into account increased these savings by 1.2 %, 5.4 % and 5.5 % respectively.

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Sustainable and energy-efficient domestic hot water systems: A review

Cited by 113 publications

References 73 publications

Energy flexibility potential of domestic hot water systems in apartment buildings

Energy flexibility potential of domestic hot water systems in apartment buildings

Engineering Skills and Knowledge Related to nZEB Construction

Optimal schedule and temperature control of stratified water heaters

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