Refrigeration & Air Conditioning - Science topic

This study introduces a groundbreaking magnetocaloric heat pump (MCHP) system that replaces traditional rare earth-dependent fixed-bed regenerators with a MnFePSi nanoparticle slurry (50 nm, 10% vol.), achieving simultaneous refrigerant and heat transfer functions. Experimental evaluations under controlled conditions (23°C ±0.2°C, 10 K span) demons...

Review Hydrogen Storage in Zeolites: A Mini Review of Structural and Chemical Influences on Adsorption Performance Baran Taşğın 1,*, Jiří Ryšavý 1, Thangavel Sangeetha 2,3, and Wei-Mon Yan 2,3 1 Energy Research Centre, Centre for Energy and Environmental Technologies, VSB—Technical University of Ostrava, 17. listopadu 2172/15, 708 00 Ostrava, Czech...

Article Safety Evaluation of Catalytic Synthesis Off-Gases through Explosion Pressure Determination Jakub Čespiva 1,*, Jan Skřínský 1, Thangavel Sangeetha 2,3, and David Kupka 1 1 Energy Research Centre, Centre for Energy and Environmental Technologies, VSB—Technical University of Ostrava, 17. listopadu 2172/15, 708 00 Ostrava, Czech Republic 2 Dep...

En los últimos años, los impactos del calentamiento global han aumentado y se han hecho más visibles a través de fenómenos climáticos extremos. Como parte de los compromisos voluntarios ante el Acuerdo de París, Guatemala se comprometió en 2021 a reducir 6.09 millones de tCO2 equivalentes para el año 2030. Entendiéndose como un sector que debe llev...

Hydrofluorocarbons (HFCs) are widely used in refrigeration, air conditioning, heat pumps (RACHP), and various other applications such as aerosols, fire extinguishers, foams, and solvents. Initially, HFCs were adopted as the primary substitutes for ozone-depleting substances (ODSs) regulated under the Montreal Protocol. However, many HFCs are potent...

Recovery and reuse of condensate generated from air conditioning system is becoming crucial for promoting sustainability in building environments. This approach is gaining significance in combating water scarcity and rising water needs, particularly in regions with hot and humid climates. Air conditioning condensate is a result of the cooling proce...

A heat sink is a device that helps absorb or dissipate heat from the surrounding area using extended surfaces or fins in various geometries. This technology finds its applications in various thermal applications, including power plants, refrigeration, air conditioning systems, electric and electronic devices, and chemical industries. The most commo...

Millions of compressors are used in refrigeration, air conditioning and heat pump systems. Their energy consumption is the most significant contributor to the efficiency of an entire HV AC system. The component specific isentropic efficiency is used for the energetic evaluation of compressors in accordance with globally standardized test procedures...

Thermoelectric refrigeration technology is mainly through the Peltier effect to achieve refrigeration, thermoelectric refrigeration air conditioning needs to be combined with a certain air flow rate to realize the separation of cold and heat, and make full use of the cold end to realize the refrigeration function, or else the refrigeration efficien...

This study investigates the implementation levels of Heutagogy, Peeragogy, and Cybergogy approaches among instructors at vocational colleges in Malaysia. Employing a quantitative survey research design, data were collected from a sample of 241instructors across 15 vocational colleges, representing various Technology fields such as Automotive, Elect...

Compression-type air-conditioning heat pump systems used in high-temperature proton exchange membrane fuel cell (HT-PEMFC) buses significantly increase the vehicle's hydrogen consumption. This study introduces a lithium bromide (LiBr) absorption refrigeration air-conditioning system into a fuel cell bus, aiming to convert the high-quality waste hea...

Webrooming is a two-part shopping process where consumers research online before purchasing in-store. Anchored in Icek Ajzen's Theory of Planned Behavior, this study explores the webrooming trend in the high-involvement appliance category, including items such as televisions, refrigerators, air-conditioning units, and washing machines. Building on...

Lo que encontramos dentro de un circuito frigorífico es una mezcla de lubricante con algún refrigerante disuelto, que cambia las propiedades originales del lubricante. En refrigeración y aire acondicionado los parámetros de funcionamiento son bien conocidos, pero para bombas de calor (HP), y aún más para bombas de calor de alta temperatura (HTHP, p...

Condensation represents the change of phase from the vapor state to the liquid state because of cooling. It is considered one of the most important heat-transfer processes in many energy-conversion systems, such as electric power generation plants. Condensation heat transfer finds its applications in power generation, refrigeration, air conditionin...

Integral reciprocating compressors (IRCs) are pivotal in a wide array of industrial applications, including refrigeration, air conditioning, and gas compression. As industries seek to reduce energy consumption, minimize operational costs, and meet stringent environmental regulations, the role of retrofit technology in enhancing the environmental an...

Small-scale vapour-compression systems for refrigeration, air conditioning, and heat pump (RACHP) applications guarantee several essential human needs. The global energy and environmental policies have compelled these solutions to take a new sustainable growth path, i.e., the adoption of low global warming potential (GWP) refrigerants. The working...

Translated version to facilitate understanding of how fugitive emissions are considered in greenhouse gases calculations.

Sustainable development policy focuses on reducing the carbon footprint generated by the global industry and energy sector. Replacing conventional energy sources with environmentally friendly ones requires advanced research to increase energy efficiency and reduce the instability and intermittence of renewable sources. Moreover, adsorption chillers...

Documents such as the Lisbon Protocol and the EU Green Pact call for the development of environmentally friendly processes and technologies to drastically reduce greenhouse gas emissions (carbon dioxide, freons, etc.) and limit the devastating consequences of climate change. Today, most industrial refrigeration, air conditioning and personal comfor...

At European and national level there is Directive 2013/29/EU of the European Parliament and of the Council of 12 June 2013 on the harmonisation of the legislation of the member states relating to the making available on the market of pyrotechnic articles and Decision 1102 of 10 December 2014 issued by the Government of Romania for the national regu...

An absorption cycle is a heat-activated thermal cycle. It exchanges only thermal energy with its surroundings; no appreciable mechanical energy is exchanged. Furthermore, no appreciable conversion of heat to work or work to heat occurs in the cycle. Absorption cycles find use in applications where one or more of the heat exchanges with the surround...

El objetivo primordial en este proyecto fue el mantenimiento correctivo de un banco experimental ubicado en el laboratorio de refrigeración y aire acondicionado, donde los estudiantes profundizan temas como el ciclo de refrigeración, control de la temperatura, presión, entre otros. Principalmente, se observó que el banco energizado no funcionaba, p...

This study employs Design Research that aims to develop teaching material in Mathematics in the Modern World (GECMAT) based on the students’ learning styles and mathematics performance during the midterm period of the first semester of the school year 2018 – 2019. The participants of study were the 216 First Year Students taking Bachelor of Science...

This communication studies the importance of convective heat transfer is intensified remarkably in various disciplines of modern engineering sciences and technological development such as heat exchangers, refrigeration, air conditioning, food processing, damage of crops and many more. The main focus of this study is to develop a mathematical modeli...

This presentation outlines the main characteristics of solar energy incident on the Earth, the different types of collectors used to convert it into thermal energy and the different applications developed: water heating, thermal power plants, refrigeration, air conditioning and distillation. Corrected application exercises complete the presentation...

Artificial intelligence (AI) models for refrigeration, heat pumps, and air conditioners have emerged in recent decades. The universal approximation accuracy and prediction performances of various AI structures like feedforward neural networks, radial basis function neural networks, adaptive neuro-fuzzy inference and recurrent neural networks are en...

Twin-screw compressors are widely used in industry, especially in compressed air, refrigeration, air-conditioning and process gas which consume a significant part of the world’s energy. Nowadays, oil-injected compressors represent the majority of twin-screw compressors in the market due to their high efficiency and reliability. The oil-free compres...

Surface air cooler is widely used in refrigeration, air conditioning, chemical dehumidification, and other related fields. Nowadays, the application of surface air cooler has been mature under standard working conditions, and more and more research has been carried out on its application. However, when conventional surface air coolers are directly...

In this paper, a no-core tellurite optical fiber (NCTOF)-based sensor was proposed for cryogenic temperature detection in refrigeration process. The ultraviolet adhesive (UVA) dual-curing method was operated to stablish a sandwich-like composite structure, in which a section of NCTOF was compactly sandwiched between two segments of silica fiber to...

Refrigerants are the basic working fluids in refrigeration, air conditioning and heat pumping systems. The development of refrigeration and air conditioning industry depends to a large extent on the development of refrigerants to suit various applications and the development of various system components. At present the industry is dominated by the...

Vogue of drinking beverages and liquid foods (BLFs) with ice is embedded and ever increasing in our hasty busy life. Direct use of unsafe ice and/or food ice containing pathogens in BLFs is threat to human health. In the current study, as an alternate to ice, a reusable cooling device was developed to cool some widely consumed BLFs. The device engi...

As the adverse effects of climate change continue to manifest in extreme, deadly, and costly weather events, the increasing need for developing alternative countermeasures in the fight against global warming is becoming second to none. Refrigerants are the key resource in (almost) all refrigeration, air conditioning and heat pump systems; however,...

Ghana experienced widespread power shortages due to series of droughts spanning from the 1980s to the 1990s. Energy efficiency programmes were identified to solve these energy supply challenges. Consequently, the residential sector has been recognized as an important target group for energy efficiency programmes in the country. The residential sect...

In the last decade, halogenated ethenes have seen an increasing interest for different applications; in particular, in refrigeration, air-conditioning and heat pumping. At the same time, their adverse effects as atmospheric pollutants require environmental monitoring, especially by remote sensing spectroscopic techniques. For this purpose, an accur...

RESUMEN En este artículo se presentan las ventajas, desventajas y principales características de funcionamiento de las bombas chorro, al igual que su clasificación de acuerdo al uso y aplicación. Por último, se presenta una breve reseña de las principales investigaciones que se han realizado en el mundo alrededor del uso de estos equipos, especialm...

The refrigeration, air-conditioning and heat pumping industries are essential sectors of the world economy. The list of the major synthetic refrigerants characterized by the non-flammability, low toxicity, good thermophysical properties and stability are reviewed. The HCFCs and fully halogenated CFCs refrigerants are responsible for the destruction...

CONTENIDO Buenas prácticas ambientales aplicadas a la refrigeración y aire acondicionado/Climatización Caracterización de defectos de fundiciones de hierro fundido en horno tipo cubilote Corrosión en una tubería de acero al carbono para transporte de hidrocarburos Soldabilidad de fundiciones de hierro gris, hierro modular y de acero inoxidable A...

Home automation systems allow us to control through smart home technology. Starting from lighting, heating, refrigeration, air conditioning, TV, entertainment audio and video systems, security, and camera systems that can communicate with each other which can be controlled remotely, from any location via Smartphones or the Internet. The research de...

Italy has not yet presented to the scientific community any elastocaloric prototype suitable for refrigeration/air conditioning. The SUSSTAINEBLE project was born from the idea to build a demonstrative elastocaloric prototype for environmental conditioning. The prototype is planned to be rotary and composed by a few bunches of elastocaloric wires c...

The phase out of anthropogenic ozone‐depleting substances such as chlorofluorocarbons under the terms of the Montreal Protocol led to the development and worldwide use of hydrofluorocarbons (HFCs) in refrigeration, air conditioning, and as blowing agents and propellants. Consequently, over recent years, the atmospheric abundances of HFCs have drama...

Nano fluids play a vital role in enhancing the performance of major thermal systems such as heat exchangers, Refrigeration & Air conditioning systems, Internal Combustion Engines. Among those carbon nano tubes is the most predominantly used nano particle. But the major problems associated with the carbon nano tubes are poor stability and lower disp...

Owing to the high heat transfer performance, compact design and large surface area per unit volume, the curved and helical circular tubes have many applications such as heating, refrigeration, air conditioning, steam generation, heat extraction etc. One of the ways to improve the performance of water heating systems is to enhance the performance of...

The heating and cooling industry underpins everything we do, e.g., manufacturing, commercial and residential applications. Many of these applications invariably use mechanical refrigeration technologies, consequently contributing significantly to the environmental impacts of the refrigeration, air conditioning, and heat pump (RACHP) industry both t...

Magnetic refrigeration is a cooling technology based on the magnetocaloric effect, an environmentally friendly refrigeration without greenhouse gas and high COP (viz., the coefficient of performance of heat pumps). Among the caloric technologies, the magnetocaloric energy conversion is the most developed for refrigeration, air conditioning, heat pu...

The present paper presents a review of condensation heat transfer across smooth and enhanced horizontal surfaces due to its significance in refrigeration, air conditioning and heat pump applications. The emphasizes is on the recent understanding of experimental as well as the semi-empirical correlations to investigate the heat transfer phenomena du...

Since refrigeration, air-conditioning and heat pump systems account to 25-30% of all energy consumed in the world, there is a considerable potential to mitigate the Global Warming by increasing the efficiency of the related appliances. Magnetocaloric systems, i.e. refrigerators and heat pumps, are promising solutions due to their large theoretical...

The heat exchangers are used in various fields for decades, such as in the power plants, automotive, refrigeration, air conditioning, and chemical industries, meaning they help a myriad of applications. Therefore, this paper discusses a critical issue from a practical perspective in a shell-and-tube heat exchanger. This issue is the tube-to-tubeshe...

The heat exchangers are playing an essential role in some widely used systems including automobiles, heating, refrigeration, air conditioning, distillation, in thermal power plants, district heating and as annexes to thermal machines. During the use of the heat exchanger, different phenomena occur due to the flow velocity of the fluids, the viscosi...

The Institute of Refrigeration (IOR) is an independent registered charity run for the public benefit with a membership of over 2200 individuals reflecting the diversity of the refrigeration, air conditioning and heat pump sector. The Institute provides a central resource for people from all over the world to improve the application of refrigeration...

The present paper provides a thorough numerical study of variation in geometrical parameters that affect the performance of the novel finned‐tube type heat exchanger design. The finite volume method was employed to discretize and solve the governing partial differential equations of heat conduction. A wide range of constant convective heat transfer...

The problem of vehicle window dewing not only affects the occupants' comfort in the vehicle, but also interferes with the driver's sight and potentially threatens the safety of driving as well as electronic equipment in the vehicle. Fog is a natural weather condition that can cause visibility to become zero. Now a day the air conditioners are very...

Legal requirements for the use of refrigerants increasingly restrict the use of high-global warming potential (GWP) refrigerants. As a result, there is a growing interest in natural refrigerants and in those belonging to the hydrofluoroolefins (HFO) class, which can be used on their own or in mixtures. One of them is the R1234ze(E) refrigerant, an...

Efficient solid-state refrigeration techniques at room temperature have drawn increasing attention due to their potential for improving energy efficiency of refrigeration, air-conditioning, and temperature-control systems without using harmful gas in conventional gas compression techniques. Recent developments of increased magnetocaloric effects an...

Normally, We are using refrigerating system to store the foods, Medicines..etc to extend the lives of the products. But in the existing refrigerating system which causes cooling effect with the help of refrigerants like CFC’s,HCFC’s. They are the harmful components which causes environmental Degradation. In order to overcome this we are using pelti...

Difluoromethane (HFC32) is the perfect replacement of R410A due to its lower Global warming potential (GWP as 675) that is much less than R410A (2088) and Zero Ozone Depletion Potential. R32 can achieve higher heat transfer coefficients with less quantity of refrigerant charge amount when compared to R410A. Tube-Fin heat exchangers (TFHE) are widel...

Resumo da Dissertação de Mestrado submetida ao Programa de Pós-graduação em Arquitetura, Faculdade de Arquitetura e Urbanismo – UFRJ, como parte dos requisitos necessários à obtenção do Título de Mestre em Ciências de Arquitetura. A presente dissertação de Mestrado apresenta como objeto de estudo o paradoxo entre a elevada aceitação dos benefícios...

In dehumidification type air conditioners, waste water is a by-product, caused by air cooling and condensation, like an atmospheric water generator (AWG). Refrigeration air conditioning equipment usually reduces the absolute humidity of the air processed by the system. The relatively cold (below the dewpoint) evaporator coil condenses water vapor f...

In dehumidification type air conditioners, waste water is a by-product, caused by air cooling and condensation, like an atmospheric water generator (AWG). The water, in this case, is not purified. Refrigeration air conditioning equipment usually reduces the absolute humidity of the air processed by the system. The relatively cold (below the dewpoin...

Energy is the major input to the social, economical, industrial and technological development of any country and its demand is increasing with increasing the population and improvement in the living standard. This paper presents a comparison of the energetic and exergetic performances of a vaccine storage refrigerator using refrigerant R-134a and n...

Synthetic refrigerants contributes to global warming & depletion of ozone layer. Investigations over last few decades solicit natural substances to take over the present challenge. The present work was a manoeuvre to find out the possibility of Acetone and water solution in sharply estimated ratio as natural refrigerant in vapour compression refr...

Using the residual heat from the engine exhaust and of late from the fuel cell exhaust to drive a refrigeration or air conditioning unit on-board a vehicle has been the interest of many research groups worldwide. Umpteen number of modelling studies and a few prototypes have been built in this area. In this paper, an up to date review of the heat dr...

Proceeding of the National Conference on Developments in Renewable & Future Trends in Mechanical Engineering aims to provide a common platform to research scholars, academicians, students, leading engineers, and industry personnel to interact & discuss the new advances in Renewable Energy and future trends occurrence in various aspects of Mechanica...

The plate Fin-and-tube heat exchangers are one of the most common type of heat exchangers that are widely used in variety industrial applications like space heating, refrigeration, air conditioning, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, aerospace industry and sewage treatment. It is ver...

All countries of the globe pay attention very serious to the existence of e-waste considering the content of toxic and hazardous substances in electrical and electronic equipment. This is due to the lack of appropriate electronic waste management that could potentially trigger negative effects on the environment and human health. E-waste management...

The convenience stores in Thailand presents its continuing growth in both urban and rural areas. The stores possess various electric equipment for refrigeration, air-conditioning, lighting, cooking, with 7/24 service; resulting in high electricity demand. Those stores have been persistently conducted energy conservation; however, there is still a g...

Horizontal type falling film evaporators are commonly used in multi-effect desalination (MED) plants, refrigeration, air conditioning and waste heat recovery application. In falling film evaporators, a thin liquid film covers the tube and heat is transferred from the heating medium inside the tube to the thin film. The heat transfer in falling film...

Este libro presenta los mapas del bioclima de la República Mexicana, resultado del análisis de la información climática del país, y las condiciones de confort higro-térmico, para el ser humano en las diversas regiones del territorio nacional. Para definirlas se tomó como base la ecuación propuesta por Auliciens (1990), y para el resultado, se adapt...

The liquid thermal performance is determined by its heat transfer capability for various applications and its characteristics such as liquid density, specific heat, viscosity, and thermal conductivity. For the refrigeration, air conditioning, automobiles, chemical operations and power generation, the fluids like water, air, mineral oils, ethylene g...

The third generation of fluids, the hydrofluorocarbons (HFC) was created as a main alternative to solve high ozone depletion potential (ODP), which was introduced by the previous generation. Even so, there is still considerable contribution in a high global warming potential (GWP.) For example, R134a is the most significant HFC, but it has a high G...

The requirements of the European Union (EU) regulation on fluorinated greenhouse gases has created an incentive to reduce their amount that can be placed on the EU market (including many commonly used refrigerants) to 21% of the baseline level. This study attempts to develop a methodology to predict the future refrigerant mix in refrigeration, air...

The Irish Seafood agency reports that 15% of global energy is consumed by operations related to refrigeration and air conditioning in the fish industry which stresses the importance of integration with clean renewables and adoption of smart energy management solutions. While fish processing industries have high energy costs with continuous refriger...

The rapid industrialization and growth of the world's human population have resulted in an unprecedented increase in the demand for energy, in particular, electricity. Depletion of fossil fuels and the impacts of global warming have caused widespread attention using Renewable Energy Resources (RESs), especially solar energy. This paper provides a p...

The Irish Seafood agency reports that 15% of global energy is consumed by operations related to refrigeration and air conditioning in the fish industry which stresses the importance of integration with clean renewables and adoption of smart energy management solutions. While fish processing industries have high energy costs with continuous refriger...

The issue of global warming has triggered more critical issues, and today’s refrigerants with high global warming potential (GWP) are facing the challenges of being phased out. According to 2014 Assessment Report of the Refrigeration, Air-Conditioning and Heat Pumps Technical Options Committee (RTOC Assessment Report 2014), the R410A has GWP of 210...

Difluoromethane (HFC32) is the perfect replacement of R410A due to its zero ozone depletion Potential and lower Global warming potential (GWP as 675) that is much less than R410A (2088) and Zero Ozone Depletion Potential. R32 refrigerant can achieve higher heat transfer coefficients with less quantity of refrigerant charge when compared to R410A. F...

In this study, the exergy analysis of a CO2 (R744) two-phase ejector was performed using a 1D model for both single and double choking conditions. The impact of the back pressure on the exergy destruction and exergy efficiencies was presented to evaluate the exergy performance under different working conditions. The results of two exergy performanc...

High power consumption of air conditioners and refrigerators is a big problem. Accordingly, many directions for achieving energy efficient air conditioning and refrigeration systems with environmentally friendly refrigerants need to be explored to face the depletion energy resources. Vapor compression refrigeration system is one of the many refrige...

Condensers are extensively used in refrigeration, air-conditioning and power generation systems. Condenser for the solar assisted geothermal cooling system is designed by using software simulation of condenser’s geometrical and flow parameters. The geothermal cooling system is designed to reduce electricity consumption of compressor during peak hou...

Se ha efectuado una recopilación de información bibliográfica, con el fin de articular un documento consistente que permita al lector conocer la manera de abordar la eficiencia energética en la industria de forma efectiva, en base a los enfoques más recientes y las tecnologías más avanzadas. Se estudian los sistemas de gestión de la energía como un...

Heat exchangers are widely used in many applications such as water treatment plants, refrigeration, air conditioning, and automobiles. Radiators are one form of heat exchangers in which the fluid to be cooled is passed through a series of finned tubes and the air is flowing across the tubes, thus heat transfer occurs and the temperature of the flui...

In many developing countries Like India, most of the vapor compression based refrigeration, air conditioning and heat pump systems continue to run on halogenated refrigerants due to its excellent thermodynamic and thermo-physical properties apart from the low cost. However, the halogenated refrigerants have adverse environmental impacts such as ozo...

Positive displacement compressors are critical components in today's vapor compression refrigeration, air conditioning, and heat pumping applications and can also be applied as expanders in power generation systems, such as organic Rankine cycles (ORC). The simulation of such systems is essential to predict and optimize the performance behavior at...

Concept of thermoelectric (TE) energy makes it unique because of reversible energy conversion, e.g. from thermal to electrical and vice-versa. Seebeck and Peltier effects are base of all TE energy applications. Thermoelectricity has wide range of applications due to reversible energy conversion. In recent years, with technology development and glob...

Halogenated hydrocarbons with high ozone depletion potential (ODP) were banned under Montreal Protocol (1987) due to their detrimental effects on ozone layer that shields the planet against ultraviolet radiations. The greenhouse gases (GHG) used in modern refrigeration, air conditioning, and heat pumping systems, are under Kyoto Protocol (1997)’s t...

A Heat exchanger is piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or maybe in direct contact. They are widely used in space heating, refrigeration, air-conditioning, power plant, chemical plants, petro-chemical plants, petroleum refineries ,natura...

The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. This paper provides an overview of solar thermoelectric (TE) cooling systems. Thus, this review presents the details referring to TE cooling parameters and formulatio...

Heat exchangers are used to transfer heat from one fluid stream to another fluid stream. Coiled TiTHEXs (Tube in tube Heat exchangers) are widely used in refrigeration, air-conditioning and cryogenic applications. Research has been carried out extensively on coil tubes to assess their performance. Studies on overall system level with these heat exc...

For mobile objects, at the moment, foreign companies supply for Russia a wide range of air conditioning devices based in on the refrigerant refrigerant (freon) refrigerators. They are designed for use in fundamentally different from our climatic conditions, characterized by a relatively short warm period of the year, which should be taken into acco...

Adaptive thermal comfort is the latest theory used to analyze thermal acceptability of the naturally ventilated buildings for occupants in tropical areas. Vernacular residences are considered capable to meet the thermal comfort for the occupants. The combination between adaptive and passive theory is still rarely conducted. This study aims to compa...

Transformator distribusi memiliki peran penting dalam mendistribusikan tenaga listrik sehingga peran transformator ini untuk beroperasi dengan baik harus dalam kondisi stabil. Salah satu kondisi yang mengganggu beroperasinya adalah gangguan harmonisa yang terjadi pada sistem distribusi tenaga listrik akibat terjadinya distorsi gelombang arus dan te...