Energy-saving Field Research Articles

Copper-Zinc Oxide Synergistic Approach as Low-Emissivity Material for Energy-Saving Windows

In luxurious glass buildings and constructions, heat gain (or heat loss) mostly comes through the windows. Infrared (IR) radiation is an important factor that causes the entry of heat into the buildings. To save energy consumption of air conditioners, low-emissivity (Low-E) glass coating applications are focused. In the energy-saving field, transparent conductive oxide (TCOs) are used as coatings to minimized IR entry. In this work, copper-doped zinc oxide (CZO) is synthesized for thermal reflective material. Cu(II) ions are doped to ZnO by a sol-gel method to obtain CZO nanoparticles and is coated on a glass substrate. The morphology of CZO is investigated with scanning electron microscopy (SEM); phase crystallinity is determined by X-ray diffraction (XRD); and UV-Vis-NIR spectroscopy is used to characterize UV/IR-shielding and also the optical transparency. IR cameras and in-lab thermal insulation setup are used to test the heat insulation properties. The result shows that 15% copper-doped zinc oxide has the best insulation from IR rays with the lowest temperature in the interior (T3) of 50.6°C while the outer temperature (T2) was at 85.5°C the lowering of the temperature by 34.9°C (cooler by 59%). CZO synthesized from the sol-gel method has promising properties for Low-E glass coating applications.

Fabrication of solar-reflective, hydrophobic polymer materials with excellent cooling and anti-icing properties through selective etching

Polymeric cool roofing materials have been concerned all along for their promising applications in energy-saving fields. Simultaneously, anti-icing property is another significant consideration for roofing materials. Herein, porous surfaces were constructed through immersing poly(methyl methacrylate) (PMMA)/chlorinated polyethylene (CPE) blending sheets in cyclohexane/methylbenzene/acetone (90/10/10) mixed solvent to selectively etch some components, and their cooling and anti-icing properties were investigated. Both solar reflectance (Rsol) and thermal emissivity (εT) at atmospheric window (8–13 µm) of porous sample with 30 wt% CPE (Rsol = 93.7%, εT = 87.1%) were higher than those of pure PMMA (Rsol = 13.0%, εT = 86.4%). The porous sample with 30% CPE as a simulated roof possessed the best cooling performance from cooling test: its final temperature was only 25.3 °C after 1 h solar radiation, 27.1 °C lower than that of pure PMMA. Moreover, the porous sample with 30 wt% CPE exhibited very hydrophobic and good anti-icing properties. The freezing point and the freezing time of water on the hydrophobic surface were −24.4 °C and 568 s, 7.2 °C lower and 452 s longer than those of water on the surface of pure PMMA, respectively. We believe that this solar-reflective and anti-icing porous material has potential application for the next-generation roofing material.

Temperature-humidity dual regulation of a single-core-double-shell microcapsule fabricated by electrostatic-assembly and chemical precipitation.

Humidity and temperature control materials have attracted increasing attention due to their energy saving and intelligent regulation of human comfort in the field of interior building and clothing. Phase change microcapsules have been widely used, however, most of which focus on temperature regulation without humidity control. In this work, we report a novel temperature–humidity dual regulation microcapsule with single-core–double-shell structure. FT-IR and XRD measurements confirmed that the shell materials were successfully fabricated on the paraffin core via electrostatic-assembly and the subsequent chemical precipitation method. SEM, TEM and optical microscope photos showed that the microcapsules were spherical morphology with layer-by-layer shells at a diameter around 2–5 μm. The SiO2 shell was aggregated from nano-sized particles and formed a loose and porous micro-structure, supported by the result of N2 adsorption–desorption isotherms. In addition, the synergistic effect of hydrophilic and porous loose (chitosan/GO/chitosan)–SiO2 double shells endowed the microcapsules with humidity regulation. The constructed microcapsules showed temperature regulation behavior due to its phase change performance of paraffin and good thermal durability after 10 thermal cycles. They also showed stable humidity regulation performance after repeated adsorption/desorption. The simulation experiments of temperature and humidity regulation indicated that the microcapsule could keep the temperature and humidity in a stable range. The as-prepared microcapsules have outstanding temperature and humidity regulation properties, showing an application prospects in energy-saving fields.

Optimization of phase change material component and its application in buildings

Improving the thermal transfer performance of phase change material (PCM) component has attracted more and more attention in building the energy-saving field. This paper presented an optimized PCM component which is encapsulated in a metal container, to promote the thermal performance of the wall. Thermal transfer of PCM component is optimized by adding internal fin through numerical simulation software COMSOL Multiphsics. The simulation model was verified by data from publicly available published literature. The temperature difference of PCM component in front and back heating surface (ΔTs) was employed to obtain the optimal geometric parameters including spacing (Sfin) and length (Lfin) of the fin. Thermal performance of the wall with the optimized and non-optimized PCM component was compared under the summer typical climate. The wall with optimized PCM component has the best capacity for heat storage and release. The interior surface temperature reduction of the wall with optimized PCM component is lower by 2.1 ºC than reference wall.

PROSPECTS FOR THE DEVELOPMENT OF ENERGY SECURITY AND ENERGY EFFICIENCY OF AGRICULTURAL PRODUCTION IN UKRAINE

In the article, pressing issues are examined in relation to the prospects of energy saving and energy efficiency of agricultural production. Investigational, that the necessary condition for the development of agricultural production are optimally certain volumes of current power resources. An author focuses on energy efficiency in Ukraine, which will help reduce the power-hungriness of GDP by 20 oh end of 2020, and the potential for energy efficiency increase will help to develop the latest technologies in the field of energy savings. Reasonably, the achievement of high results depends on the coordinated efforts of public, business and community authorities, and the obstacles to a realization of the energyeffective programs arise up through a shortage of knowledge, resources and financing. It is well-proven that the basic income in the future will be generated precisely in the field of resource-efficient production and processing of products in rural areas.

Preparation of Colorful, Infrared-Reflective, and Superhydrophobic Polymer Films with Obvious Resistance to Dust Deposition.

In recent years, polymer films containing deep color and near-infrared (NIR)-reflective pigments have received much attention for their potential applications in energy-saving fields. However, in practical environments, dust present in the air is easily adsorbed and adheres to the surface of these films, thus gradually reducing their NIR reflectance. In this work, black or deep-red infrared-reflective pigments were firstly mixed with melted low-density polyethylene (LDPE) and then the resulting composite was thermally pressed on to a metal template possessing micro- and nanostructure surface roughness. After being cooled to a suitable temperature, the LDPE composite film was peeled from the template. Ultraviolet-visible-near-infrared spectroscopy and an indoor infrared lamp irradiation test both confirmed that the prepared films exhibit high NIR reflectance and high heat reflectance. Moreover, due to the stretching-controlled micromolding process, the films all exhibited a superhydrophobic (SH) property. After incubation in outdoor conditions for 1 month, the NIR reflectance of the SH films remained almost consistent; however, the films that did not possess SH property showed a marked decrease in their ability to reflect NIR radiation. By a combination of scanning electron microscopy imaging, we conclude that our films are able to resist dust deposition and thus avoid deterioration of their infrared-reflective properties. We believe that these colorful, infrared-reflective, SH, and cost-effective films have potential application for reducing energy consumption where minimal solar irradiation is required.

COMPUTER MODELLING OF THERMAL TECHNICAL SPACESS IN ASPECT OF HEAT TRANSFER THROUGH THE WALLS

This paper presents the analysis of complex problems in the field of energy savings and it is focused on the new concept of thermal analysis derived from harmonic character of temperature changes in building environment – especially in a fruit storages – with aspect on conductive heat transfers through walls. This changeable influence of variable weather temperature on internal temperature of technical chamber depends on thermal inertia of building. The paper describes research work on methods concerning heat transfers through walls of thermal technical chambers in the impact of sinusoidal nature of the changes in atmospheric temperature. The purpose for the research is to point out areas subjected to the highest energy losses caused by building’s construction and geographical orientation of walls in the aspect of daily atmospheric temperature changes emerging on chamber exterior. The paper presents exemplary measurement results taken in Lublin region during various periods throughout a year.

Citric acid induced W18O49 electrochromic films with enhanced optical modulation

Electrochromic materials exhibit promising applications in energy-saving fields for their ability to control heat from outdoors. Nanostructured W18O49 has drawn attention for its one-dimensional structure to transfer charge efficiently as a remarkable electrochromic material. W18O49 bi-layer films were fabricated through a facile one-step solvothermal process with citric acid as a chelating agent. The addition of citric acid improved the deposition on the substance, and a nanostructured film with a denser layer at the bottom and a tussock-like upper layer was obtained. The bi-layer film exhibited an enhanced optical modulation of 68.7%, a coloration efficiency of 82.1 cm2/C with stability over 400 cycles, and fast response times (1.4 s and 2.3 s for bleaching and coloring), with expectation to be applied in the electrochromic field.

COMPUTER AIDED THERMAL PROCESSES IN TECHNICAL SPACES

This paper describes research work on methods concerning heat transfers through walls of thermal technical chambers. The paper presents the mathematical and physical analysis of problems in the field of energy savings and material selection in thermal chambers in controlled gaseous environment. The purpose for the research is to point out areas subjected to the highest energy losses caused by building’s construction and geographical orientation of walls in the aspect of daily atmospheric temperature changes emerging on chamber exterior. Thermal problems were solved using computer aided support. The paper presents exemplary measurement results taken in Lublin region during various periods throughout a year.

In Situ Triggering and Dynamically Tracking the Phase Transition in Vanadium Dioxide

As the most widely studied thermochromic material, monoclinic vanadium dioxide (VO2 (M)) shows promising applications in the energy-saving field. Solid-state transformation, especially fast annealing, plays an important role in the production of VO2 nanomaterials. On the other hand, the fast process makes it impossible to real-time monitor the phase transition in VO2. In this paper, a differential scanning calorimetry technique is proposed to in situ trigger and dynamically track the phase transition of VO2 nanoparticles, which gives a distinguished method to identify the underlying size-dependent and defect-mediated structure phase transition.

Analysis on the Development of Residential Building Energy Conservation

Building Energy Conservation, especially the research about residential building energy in face of the worldwide energy crisis is particularly urgent. At present, various countries have an in-depth study of the residential building energy to explore different methods, new building materials, and new technology(such as new thermal windows and doors), as well as the use of new energy has been put more attention to in energy conservation field. Comparing the residential buildings between domestic and overseas countries’ progress about related technologies, we could find some evolution and look to the prospects for the future in energy-saving field. We took a domestic project that used energy-saving technology as a practical example, and then made a simple overview of the current energy situation in China so as to get a glimpse of the development about residential building energy-saving. Finally, the article provided some comments about this topic in sustainable view.

The energy efficiency directive and the challenges for the Hellenic legislative process in times of crisis

The objective of this article is to present the basic axes of the recent Directive 2012/27/EU on energy efficiency and to highlight the Member States' challenges during its implementation due to the economic crisis. The innovations it introduces, the new policies and the measures, which need to be adopted by Member States, as well as the seeming effectiveness of the Directive, are critically set out in the first part. In the second part, the Directive's dynamics is presented, in the sense of its implementation in specific geographical areas, such as Member States, which face aggravated financial problems. Greece constitutes a typical example of a state plagued by economic crisis. The issue whether this Directive can be implemented in such states and to what extent its objectives can be realized is critically analysed. The whole approach is made through a critical historical overview of the course of national legislation in the field of energy savings; shortcomings and gaps are detected; suggestions on necessary legislative initiatives are articulated. It should be noted that the present paper is based on literature mostly relating to primary sources (primary and secondary EU law, EU case law and Greek law) with a few review papers.

Assessment of the technical potential for multifunction building zero-carbon renovation with EnergyPlus

Energy consumed in the building field accounts for 30-40% of social energy consumption in the entire world. The energy used in office-educational buildings, especially in developed countries, takes up a large proportion, because of the high occupant density, long running time and high brightness and comfort requirement. This research aims at predicting the renovation potential for office-educational building in the energy-saving aspect. One typical existing educational building in the UK has been chosen as the research object; EnergyPlus computer model, which accurately reflects the building style, material, structures and Heating, Ventilation and Air Conditioning system is established. After the simulation of energy performance and carbon emission of the original building, some insulation measures and renewable technologies (photovoltaics, solar thermal etc.) have been added as the renovation method. Then, theoretical calculation and computer simulation about the effect of the renovations above have been conducted to reflect the improvement. Carbon-saving effects of renovation methods were compared and analyzed. Only 2.2% of carbon emissions can be reduced by improving the air-tightness of the building and the U-value of windows, but great carbon saving achieved by adding renewable devices. About 40.8% of the carbon emissions reduced due to the application of all the renovation methods. The result of this study will provide some critical references for the choosing and prediction of renovation methods in the energy-saving field in the UK.

The Analysis of Government Re-Regulation Caused by Externality of Building Energy-Saving

In this paper, aiming at the problem of “market failure” in the building energy-saving field, we discuss the principle of externality in this field and analyze how the externality of building energy-saving leads to the rent-seeking behavior of building energy-saving products manufacturers or developers using the economic theory. Based on the Game theory, we analyze the revenue and cost of unproductive activities between building energy-saving regulation department and building energy-saving products manufacturers or developers, how the government supervises and regulates corruption which comes from unproductive activities, and the tripartite game model of the rent-seeking behavior in the domain of energy-saving is built. On the basis of the establishment and solution of the tripartite game model，we put forward effective countermeasures and methods for government re-regulation.

The Analysis of Government Re-Regulation Caused by Externality of Building Energy-Saving

In this paper, aiming at the problem of “market failure” in the building energy-saving field, we discuss the principle of externality in this field and analyze how the externality of building energy-saving leads to the rent-seeking behavior of building energy-saving products manufacturers or developers using the economic theory. Based on the Game theory, we analyze the revenue and cost of unproductive activities between building energy-saving regulation department and building energy-saving products manufacturers or developers, how the government supervises and regulates corruption which comes from unproductive activities, and the tripartite game model of the rent-seeking behavior in the domain of energy-saving is built. On the basis of the establishment and solution of the tripartite game model，we put forward effective countermeasures and methods for government re-regulation.

Building Energy-Efficiency Running Mode of Large-Scale Public Building: Based on Energy Performance Contracting

Energy performance contracting plays a key role in improving the building energy-efficiency in China. This paper introduces the current situation of energy-efficiency of large-scale public building in China and provides an overview of energy performance contracting, and then puts forward an innovative energy-efficiency running mode. This paper tries to offer theoretical references for the development of EMC in energy-saving field of large-scale public buildings.

Using principal component and cluster analysis in the heating evaluation of the school building sector

In the field of energy savings in buildings, the interest towards the school sector is deeply motivated: schools have standard energy demands and high levels of environmental comforts should be guaranteed. The University of Athens in collaboration with the School Authority of Greece undertook a complete program on energy classification and environmental quality of school buildings. Data on energy consumptions were gathered and analysed with the participation of 1100 schools from all the prefectures of Greece. The data have been provided by the school authority of the country (OSK), in collaboration with the management of each school building. With regards to the size of the building and the external climate variability (HDD-method) energy normalization techniques have been applied in order to homogenize the data set. An energy classification tool has been created through clustering techniques, using the collected data regarding the heating energy consumption and as a result five energy classes have been defined. To evaluate the potential energy conservation for each class, the typical characteristics of school buildings belonging to an energy class have to be identified. A new methodology based on the use of the principal components analysis (PCA) has been developed. The method allows to define in an accurate way the typical building of each energy class and thus to perform analysis on the potential energy savings for the specific group of school buildings. By reducing the dimensionality of the problem, a bi-dimensional graphic in the first two PCs coordinate system promotes the understanding of the correlation between the examined variables, as well as the determination of sub-groups of school buildings with similar characteristics. The typical school of seven variables sample is defined as the closest to the medians in the principal components’ coordinate system.

Identification of households' barriers to energy saving solutions

PurposeThe purpose of this paper is to identify households' barriers to energy saving solutions. Six types of barriers are introduced. The question to be answered is: what is the strength and relevance of the various barriers for changing consumer energy behaviour?Design/methodology/approachThe method is focus group interviews. Focus groups do not aim at giving a representative picture of the population at large, but aim at recording and documenting a wide range of typical responses and reactions. The focus groups were recruited among a group of people who were actively looking for new dwellings and a reference group of environmentally conscious participants.FindingsThree barriers out of the six proposed were found to be relevant in this study: Cultural‐normative, economic and information.Research limitations/implicationsEnergy saving solutions are technically and socially complex matters, so it is important to advice and guide consumers to make changes that contribute substantially, rather than mere symbolic changes.Practical implicationsThe finding that consumers not only need information on what and how to save energy, but also need help in identifying when they should do their investments is important for various actors involved in implementation of energy saving solutions.Originality/valueMeasures in the field of energy savings have had various successes. This article which concentrates on the barriers in this field can contribute to increased success rates.