Incorporating nano-scale material in solar system to reduce domestic hot water energy demand

Proper adjustment of domestic hot water (DHW) load structure can balance energy demand with the supply. Inefficiency in primary energy use prompted Omsk DH company to be a strong proponent of a flow controller at each substation. Here the return temperature is fixed to the lowest possible value and the supply temperature is solved. Thirty-five design scenarios are defined for each load deviation index with equally distributed outdoor temperature ranging from +8 for the start of a heating season towards extreme load at temperature of -26°C. All the calculation results are listed. If a flow controller is installed, the customers might find it suitable to switch to this type of DHW supply. Considering an option with direct hot water extraction as usual and a flow controller installed, the result indicates that the annual heat consumption will be lower once network temperatures during the fall or spring months are higher. The heat load profiles obtained here may be used as input for a simulation of a DH substation, including a heat pump and a tank for thermal energy storage. This design approach offers a quantitative way of sizing temperature levels in each DH system according to the listed methodology and the designer's preference.

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Flexibility Services to Minimize the Electricity Production from Fossil Fuels. A Case Study in a Mediterranean Small Island

Energies ◽

10.3390/en12183492 ◽

2019 ◽

Vol 12 (18) ◽

pp. 3492 ◽

Cited By ~ 4

Author(s):

Crainz ◽

Curto ◽

Franzitta ◽

Longo ◽

Montana ◽

...

Keyword(s):

Energy Demand ◽

Heat Pumps ◽

Water Desalination ◽

Hot Water ◽

Electricity Production ◽

Mixed Integer ◽

Programming Algorithm ◽

Small Island ◽

Domestic Hot Water ◽

Diesel Generators

The design of multi-carrier energy systems (MESs) has become increasingly important in the last decades, due to the need to move towards more efficient, flexible, and reliable power systems. In a MES, electricity, heating, cooling, water, and other resources interact at various levels, in order to get optimized operation. The aim of this study is to identify the optimal combination of components, their optimal sizes, and operating schedule allowing minimizing the annual cost for meeting the energy demand of Pantelleria, a Mediterranean island. Starting from the existing energy system (comprising diesel generators, desalination plant, freshwater storage, heat pumps, and domestic hot water storages) the installation of solar resources (photovoltaic and solar thermal) and electrical storage were considered. In this way, the optimal scheduling of storage units injections, water desalination operation, and domestic hot water production was deduced. An energy hub model was implemented using MATLAB to represent the problem. All equations in the model are linear functions, and variables are real or integer. Thus, a mixed integer linear programming algorithm was used for the solution of the optimization problem. Results prove that the method allows a strong reduction of operating costs of diesel generators also in the existing configuration.

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Characterising Draught in Mediterranean Multifamily Housing

Sustainability ◽

10.3390/su11082433 ◽

2019 ◽

Vol 11 (8) ◽

pp. 2433

Author(s):

Jesica Fernández-Agüera ◽

Samuel Domínguez-Amarillo ◽

Miguel Ángel Campano

Keyword(s):

Social Housing ◽

Energy Demand ◽

Hot Water ◽

Outdoor Air ◽

Multifamily Housing ◽

Building Envelopes ◽

Domestic Hot Water ◽

European Cities ◽

Occupant Comfort ◽

Communal Areas

Social housing dating from the postwar years through the end of the twentieth century is one of the major stores of European cities’ residential stock. As it is generally characterised by a poor thermal performance and an inefficient control of energy consumption, it constitutes one of the main targets for residential heritage renewal. This study aimed to locate and quantify air leaks across building envelopes in Mediterranean multifamily housing with a view to curbing the uncontrolled inflow of outdoor air that has a direct impact on occupant comfort and housing energy demand. Airtightness tests conducted in a series of protocols to quantify draught across envelope elements were supplemented with qualitative infrared thermographic and smoke tests to locate leakage pathways. Air was found to flow mainly across façade enclosures, primarily around openings, as well as through service penetrations in walls between flats and communal areas accommodating electrical and telecommunication wires and water supply, domestic hot water (DHW), and drainage pipes. The general absence of evidence of draught across structural floors or inter-flat partitions was consistent with the construction systems in place.

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A Software Optimization of the Solar Energy System Performance

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.899.199 ◽

2014 ◽

Vol 899 ◽

pp. 199-204

Author(s):

Lukáš Skalík ◽

Otília Lulkovičová

Keyword(s):

Solar System ◽

Solar Energy ◽

System Performance ◽

Solar Collector ◽

Energy Demand ◽

Fossil Fuels ◽

Thermal Protection ◽

Energy Systems ◽

Energy System ◽

Hot Water

The energy demand of buildings represents in the balance of heat use and heat consumption of energy complex in the Slovak national economy second largest savings potential. Their complex energy demands is the sum of total investment input to ensure thermal protection and annual operational demands of particular energy systems during their lifetime in building. The application of energy systems based on thermal solar systems reduces energy consumption and operating costs of building for support heating and domestic hot water as well as savings of non-renewable fossil fuels. Correctly designed solar energy system depends on many characteristics, i. e. appropriate solar collector area and tank volume, collector tilt and orientation as well as quality of used components. The evaluation of thermal solar system components by calculation software shows how can be the original thermal solar system improved by means of performance. The system performance can be improved of more than 31 % than in given system by changing four thermal solar system parameters such as heat loss coefficient and aperture area of used solar collector, storage tank volume and its height and diameter ratio.

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Comparative Analysis of Energy Demand and CO2 Emissions on Different Typologies of Residential Buildings in Europe

Energies ◽

10.3390/en12122436 ◽

2019 ◽

Vol 12 (12) ◽

pp. 2436 ◽

Cited By ~ 2

Author(s):

Julià Coma ◽

José Miguel Maldonado ◽

Alvaro de Gracia ◽

Toni Gimbernat ◽

Teresa Botargues ◽

...

Keyword(s):

Comparative Analysis ◽

Co2 Emissions ◽

Energy Demand ◽

Residential Buildings ◽

Residential Building ◽

Cold Climate ◽

Hot Water ◽

Data Sources ◽

Building Sector ◽

Domestic Hot Water

The building sector accounts for one third of the global energy consumption and it is expected to grow in the next decades. This evidence leads researchers, engineers and architects to develop innovative technologies based on renewable energies and to enhance the thermal performance of building envelopes. In this context, the potential applicability and further energy performance analysis of these technologies when implemented into different building typologies and climate conditions are not easily comparable. Although massive information is available in data sources, the lack of standardized methods for data gathering and the non-public availability makes the comparative analyses more difficult. These facts limit the benchmarking of different building energy demand parameters such as space heating, cooling, air conditioning, domestic hot water, lighting and electric appliances. Therefore, the first objective of this study consists in providing a review about the common typologies of residential buildings in Europe from the main data sources. This study contains specific details on their architecture, building envelope, floor space and insulation properties. The second objective consists in performing a cross-country comparison in terms of energy demand for the applications with higher energy requirements in the residential building sector (heating and domestic hot water), as well as their related CO2 emissions. The approach of this comparative analysis is based on the residential building typology developed in TABULA/EPISCOPE projects. This comparative study provides a reference scenario in terms of energy demand and CO2 emissions for residential buildings and allows to evaluate the potential implementation of new supply energy technologies in hot, temperate and cold climate regions. From this study it was also concluded that there is a necessity of a free access database which could gather and classify reliable energy data in buildings.

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Influence of the quantity profile of the domestic hot water demand and the energy demand for the heating in a single-family house on the SCOP of the air-to-water heat pump

E3S Web of Conferences ◽

10.1051/e3sconf/20184400162 ◽

2018 ◽

Vol 44 ◽

pp. 00162 ◽

Cited By ~ 1

Author(s):

Kamil Skoneczny

Keyword(s):

Energy Efficiency ◽

Heat Pump ◽

Water Demand ◽

Energy Demand ◽

Hot Water ◽

Single Family ◽

Domestic Hot Water ◽

Family House

In the article it was discussed how the energy efficiency of the air-to-water heat pump can change depending on the different ways of the building usage. The author shows that the following factors influence this efficiency: the DHW demand and the demand of the energy for the heating of the building. The article shows that it is very important to take into account the cooperation of both systems, the DHW and the heating. Two models of the SCOP calculations were discussed: in monthly and hourly steps of the calculation. For each model the following assumptions were considered: the different profiles of the domestic hot water demand and the different profiles of the demand for the heating of building.

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Analysis of the scope of thermo-modernization for a residential building in order to transform it into a low-energy building

E3S Web of Conferences ◽

10.1051/e3sconf/20184400069 ◽

2018 ◽

Vol 44 ◽

pp. 00069 ◽

Cited By ~ 1

Author(s):

Maciej Knapik

Keyword(s):

Energy Demand ◽

Residential Buildings ◽

Residential Building ◽

Building Design ◽

Primary Energy ◽

Hot Water ◽

Low Energy ◽

Existing Building ◽

Domestic Hot Water ◽

Modernization Process

The article presents the problem of thermo-modernization and the reduction of energy demand for heating purposes in existing residential buildings. The thermo-modernization process has to adapt the existing building to the standard of a building with low energy demand and applicable regulations. Low-energy constructions are a result of introduction of new solutions in building design process. Their main objective is to achieve a significant reduction in demand for renewable primary energy, necessary to cover the needs of these buildings, mostly related to their heating, ventilation and domestic hot water. The article presents the results of the analysis and calculation of selected thermo-modernization variants. The results showed that thermo-modernization process of existing residential buildings is justified both energetically and economically.

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Dynamic Modelling and Validation of an Air-to-Water Reversible R744 Heat Pump for High Energy Demand Buildings

Energies ◽

10.3390/en14248238 ◽

2021 ◽

Vol 14 (24) ◽

pp. 8238

Author(s):

Paolo Artuso ◽

Giacomo Tosato ◽

Antonio Rossetti ◽

Sergio Marinetti ◽

Armin Hafner ◽

...

Keyword(s):

Experimental Data ◽

Heat Pump ◽

Energy Demand ◽

High Energy ◽

Hot Water ◽

Inlet Temperature ◽

Variable Load ◽

Water Tank ◽

Heat Flow Rate ◽

Domestic Hot Water

This paper presents a reversible heat pump based on CO2 as the refrigerant, able to provide heating, cooling, and domestic hot water to high energy demand buildings. The unit was developed and tested under the EU H2020 project MultiPACK, which has the main goal of assuring the market about the feasibility, reliability, and energy efficiency of CO2 integrated systems for heating and cooling and promoting a fast transition to low environmental impact solutions. Within the project, the confidence raising was performed by installation and monitoring of fully integrated state-of-the art CO2 systems in the Southern European Climate. With the aim of predicting the unit behaviour under variable load and boundary conditions, a dynamic model of the entire unit was developed with commercial software, considering actual components and the implemented control system and it was validated with experimental data, collected at the factory’s lab before commissioning. The validation against experimental data collected during operation as a heat pump demonstrated a maximum percentage difference between the experimental and predicted value of gas–cooler heat flow rate equal to +5.0%. A preliminary comparison with the experimental data in chiller configuration is reported, however further development was required to achieve a satisfactory validation. Lastly, the numerical model was utilized to simulate a typical operation in heat pump configuration with the system coupled with a hot water tank storage for the production of domestic hot water and space heating; the model predicts higher COP when operating in domestic hot water operation due to the lower water inlet temperature.

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A 44 m2 Low Flow Solar System for Domestic Hot Water

Energy Conservation in Buildings ◽

10.1016/b978-0-08-037215-0.50036-5 ◽

1991 ◽

pp. 169-171 ◽

Cited By ~ 1

Author(s):

Torben Esbensen

Keyword(s):

Solar System ◽

Hot Water ◽

Low Flow ◽

Domestic Hot Water

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Analysis and comparison of methods for the preparation of domestic hot water from district heating system, selected renewable and non-renewable sources in low-energy buildings

E3S Web of Conferences ◽

10.1051/e3sconf/20183003001 ◽

2018 ◽

Vol 30 ◽

pp. 03001

Author(s):

Maciej Knapik

Keyword(s):

Renewable Energy ◽

Energy Demand ◽

Renewable Energy Sources ◽

District Heating ◽

Heating System ◽

Hot Water ◽

Low Energy ◽

Energy Sources ◽

District Heating System ◽

Domestic Hot Water

The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources) methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.

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