Thermoelectric Air Conditioner Research Articles

IoT-driven monitoring and controlling to improve performance of thermoelectric air conditioning system

Thermoelectric module-based air conditioners (TEM-AC) are scalable, reliable, and have the potential to replace conventional air conditioners. However, the coefficient of performance (COP) of TEM-AC is still relatively low. Improving the COP requires a combination of temperature control, voltage control, heat recovery, airflow control, and material selection. The present study focuses on enhancing COP of the TEM-AC for building space cooling. To control and monitor the parameters of the TEM-AC, a low-cost, IoT-enabled monitoring and controlling system (MCS) is developed. The MCS helps in TEM-AC system designing as it can apply different current pulses to improve cooling capacity and control the temperature difference between both surfaces. MCS also measure all the required parameters of the TEM-AC to calculate the COP of the system and helps in reducing the calculation time for each experiment. Using a developed technique and TEM-AC design, a performance comparison of eight experimental cases has been done. Experiments have been performed in normal and control modes with different heat sinks and airflow of TEM-AC. The TEM-AC system is installed over a 16-inch × 12-inch enclosed space with a TEC-12706 module. The study indicates the COP of the system is enhanced by controlling the cold side temperature and air flow rate. For this study, maximum COP is achieved around 0.44 with control operation. The developed IoT-based monitoring and controlling system offers a promising solution for improving the performance of thermoelectric modules in building space conditioning applications.

Solar Powered Thermoelectric Air Conditioning for Temperature Control in Poultry Incubators

Proper air conditioning is crucial for hatching, growing, and reproducing poultry chickens. The existing methods are often costly and only viable for some chicken farmers. This paper presents a novel solar-powered thermoelectric module that utilizes the Peltier effect for efficient cooling and heating in poultry incubators. The proposed system consists of a Peltier module with cool and hot junctions, powered by a solar panel through a charge controller and battery. The cool junction is located in the chicken-breeding and reproduction unit, while the hot junction is situated in the egg-incubation unit. Temperature controllers maintain the required temperatures of 35–40 °C for the egg-hatching and 10–24 °C for the chicken-growing units. The experimental results demonstrate the system’s effectiveness in maintaining the desired temperatures. This solar-powered thermoelectric air conditioning system offers advantages over traditional methods, including lower energy consumption, reduced costs, and eco-friendliness. It has the potential to benefit off-grid poultry farmers and reduce energy bills for existing chicken farms. The mathematical modeling, load calculations, and prototype results show that the proposed system is best suited for providing the required cooling and heating effects in poultry incubators. This research represents a significant step forward in temperature control for poultry incubators and could revolutionize poultry farming practices, especially in remote locations with limited electricity access.

Photovoltaic Powered Dual Thermoelectric Air Conditioning System

Abstract: Nowadays energy efficient and environment friendly systems are among the emerging technologies, due to growing concerns about climate change and sustainability. According to the present scenario, the renewable energy resources are becoming the source of energy due to the decrease in non-renewable energy resources (Fossil fuels). So we presented a “Photovoltaic-Powered Dual Thermoelectric Air Conditioning System” that incorporates Peltier modules(thermoelectric material) which works on peltier effect known for their eco-friendly characteristics. Harnessing solar energy through a highefficiency PV array, this system aims to provide efficient and sustainable air conditioning while minimizing the reliance on traditional power sources. The additional benefit of this system is that it provides year round comfort i.e. cooling and heating facility in one system.

Strategies on the Optimization of Thermoelectric Systems for Heat Transfer Applications: State of the Art Review

Thermoelectric technology is one of the fast-developing technologies in the present days due to its excellent heat transfer and heat conversion capabalities. This uses the electromotive force produced by the temperature difference at each end of the device to produce electricity and vice versa. There are various applications developed based on this thermoelectric technology which includes thermoelectric coolers, thermoelectric generators, and thermoelectric air conditioners. This paper provides a comprehensive analysis of thermoelectric (TE) technologies, starting with a complete summary of their working principles explaining the effects like Seebeck, Peltier, and Thomson effects, as well as optimization techniques, applications, semi-conductor materials used, and potential future developments.

The extreme high cooling capacity thermoelectric cooler optimal design for kilowatts scale thermoelectric air-conditioner of high-speed railway carriage

In recent 20 years, the rapidly development of thermoelectric materials promotes thermoelectric s application in large scale cooling area, i.e. air-conditioner. To provide quiet working environment for the driver of high-speed railway, a kilowatt scale air-conditioner was designed. Firstly, a novel thermoelectric cooler with maximum cooling capacity of 450 W was designed with 199 thermoelectric elements, and the cooling performance were investigated under different cold and hot side heat exchange capacity. Second, the hot and cold side heat exchangers were optimized adopting genetic algorithm. Finally, a high coefficient of performance (COP) thermoelectric air conditioning (TEAC) system was designed for high-speed railway locomotive. The TEAC system comprising 16 TECs achieved a cooling capacity of 2342 W with a COP of 0.5 in cooling mode, and meets one 1HP TEAC requirements. The temperature field inside the locomotive was uniform and exhibited a linear correlation with the supplied air temperature. This research demonstrates the utility of high-power TEAC in high-speed railway carriages, providing valuable insights for the application of TEAC technology.

Novel design of thermo-electric air conditioning system integrated with PV panel for electric vehicles: Performance evaluation

Traditional air conditioning may be inappropriate for electric vehicles due to its moving parts noise besides using chlorofluorocarbons that harm the environment. In addition, it consumes a significant portion of the stored energy in batteries, reducing the vehicle's driving range. So, in this paper, a novel design of thermo-electric cooling (TEC) system coupled with a photovoltaic (PV) panel replacing the vehicle roof is studied. This system consists of a sandwich of PV panel outside the vehicle and TEC inside with a heat sink system integrated between them. The air temperature variation in the cabin during the daytime is predicted by solving a complete mathematical transient thermal model of the whole system before and after mounting the cooling system. The air streams through the vehicle moving are exploited to improve the TEC and PV system performance. The system performance is investigated for different cases during the day with and without including the PV output power and for the vehicle parks inside or outside. The results indicate that, for each scenario, the number of used TEC modules influences the system performance where the best number varies between 128 and 98. Coupling the PV panel with the TEC system reduces the daily required energy from batteries by about 19%. Running the TEC system during parking from 8 to 10 am decreases the cabin air temperature from 47.5 to 34°C while the input power declines by about 45%, which reduces the interior temperature to 25°C in 10 min (transition time). The contribution of the PV panel based on the studied conditions can increase the range of the vehicle by 10.4 km/day and about 160kWh/year energy saving. The reduction in the input power during transition time reaches 27.8% when the vehicle speed increases from 30 to 60 km/h, while this ratio declines to 10.8% as the vehicle speed rises from 60 to 90 km/h. During vehicle moving, powering the TEC system by the PV panel only can prevent the cabin temperature from rising over 40°C, whereas during parking, there is an optimum fan air velocity that gives the maximum reduction of the cabin temperature.

Performance Evaluation of PV Panel Powered Dual Thermoelectric Air Conditioning System

Thermoelectric air condition system (TEACs) powered by solar photovoltaics is useful for thermal comfort applications, especially when there is a direct energy source like sunlight. This paper presents experimental investigations of solar-powered thermoelectric air conditioning for both cooling and heating modes. The experiments were carried out in a test room whose volume is 1 m3 under the climatic conditions of the city of Baghdad. In the summer, the thermoelectric device functions as a Peltier cooler. The cold side absorbs the heat from the inside to lower the room's temperature. As for winter, the heat is released from the thermoelectric Peltier module by reversing the current applied to the thermoelectric Peltier to raise the room's temperature. In this work, the thermoelectric air condition system was supplied with different electrical power supply values with time intervals between the ON/OFF operations. The results showed that the system could heat and cool the air well in different operation conditions. The lowest temperature (22°C) is achieved in the cooling mode, with a Coefficient of Performance (COP) of 0.64 and an exergy efficiency of 0.47. In contrast, in the heating mode, the highest temperature is (31°C) with a COP of 0.87 and exergy efficiency of 0.75. This simple and eco-friendly method can minimize the cooling and heating load in the room.

Performance investigation of new design thermoelectric air conditioning system for electric vehicles

Conventional automobile air conditioning systems use environmentally harmful Chlorofluorocarbons. This method also makes noise and uses a lot of battery energy, making it unsuitable for electric vehicles. So in this paper, the performance of a newly designed cooling system based on the thermo-electric cooling technique installed on the vehicle's roof is proposed and investigated. A complete theoretical transient thermal model based on energy balances is constructed, solved, and validated. The results show an optimum value of the used number of thermoelectric modules, which depends on the input power. This value is 150 for an input power of 200 W and 100 for an input power of 1000 W. At an ambient temperature of 42 °C and without applying a cooling system, moving vehicle with three persons and closed windows, its cabin temperature reaches about 66 °C; in contrast, after applying the TEC system, this temperature reaches around 26 °C at input power 1000 W. The coefficient of performance of the system reduces from about 3 to about 0.85 by increasing the input power from 200 to 1000 W, respectively. Although the coefficient of performance of this system is lower than that of the conventional, it has advantages that make it competitive with conventional air conditioning systems. An economic study based on the Egyptian market shows that the annual cost of the thermo-electric cooling system is lower than that of the conventional one.

Performance analysis of heat pipe-cooled two-stage thermoelectric air conditioner

A detailed model of heat pipe-cooled two-stage thermoelectric (TE) air conditioner is established. The performance is analysed comprehensively including the cooling power, coefficient of performance (COP), thermodynamic perfectibility and extreme temperature difference. The influences of key parameters including working current, distribution ratio of TE elements and heat pipe parameters are analysed by numerical simulation. The working current and the TE element number ratio are optimized for the maximum cooling power and the maximum COP respectively. The influences of the cross-sectional area, the length of the TE element and the temperature difference on the optimal variables and optimal performance is obtained. The results show the refrigeration performance of the TE air conditioner can be effectively improved by heat pipe cooling. The two-stage mode can effectively improve the refrigeration temperature difference. The extreme temperature difference can be improved from 60 K to 110 K.

Performance modelling on a thermoelectric air conditioning system using high power heat sinks and promoting waste heat utilization

Performance modelling on a thermoelectric air conditioning system using high power heat sinks and promoting waste heat utilization

Design and experimental study of an outdoor portable thermoelectric air-conditioning system

This study aims to identify suitable microclimate cooling systems to reduce heat stress and improve human thermal comfort. A portable thermoelectric air conditioner was developed for local cooling of the human body. Effects of core components thermoelectric refrigerators (TECs), hot end heat dissipation, intake flow and cold end heat exchangers on TEAC performance. It is shown that, remarkably, this operating voltage can be distinguished from the optimal voltage for the maximum operational performance of TEAC. When the TECs operating voltage is 4V, the maximum COP is 2.2, and the best operating voltage is 10V, the maximum cooling capacity is 26.7 W (COP=0.92). Simulation data show that the area of the diffuser can effectively control the contact between the air and the cooling surface with an error of less than 10% compared to the experimental results. The fans and radiators attached to the hot side of the TEM play an important role in keeping the temperature difference on the hot side of the TECs as small as possible, by dissipating the heat generated on the hot side of the TEM to the external environment. In addition, the experimental refrigeration capacity is greater than 26.7 W and the new system has ultra-quiet operation at large refrigeration capacity, which has promising potential for advanced refrigeration, building air conditioning, ventilation systems and other applications. • Thermalelecrtic air conditioner (TEAC) can achieve a cooling capacity of 26.7W and a cooling coefficient of 0.92, enabling local cooling of the human body. • The maximum cooling capacity of thermoelectric refrigerator varies nonlinearly with the surface area and height of thermoelectric leg. • The increase of cooling capacity decreases with the increase of intake flow rate. • Increasing the strength of heat dissipation at the hot end of the thermoelectric cooler has a larger effect on the TEAC cooling capacity than on the cooling coefficient.

Thermodynamic analysis of a thermoelectric air conditioner

This paper discusses the results of tests done to investigate the performance of a thermoelectric air conditioner (TEAC). The TEAC is composed of twelve thermoelectric modules (TEMs). The TEMs were fixed to rectangular fin heat sinks on both their hot and cold sides. With an increased input<em> </em>voltage, the cooling capacity increased. At a 6 V input voltage flow, a suitable condition occurred. The rate of hot air flow was 0.48 kg/min, and the cooling capacity was 157.0 W, resulting in an outlet<em> </em>air temperature of 28 <sup>o</sup>C. The coefficient of performance (COP) was calculated and found to be 0.92. Exergy analysis is used to determine the energy flows and second law efficiencies of a TEMs system and its components. The exergy destruction and second law efficiency were observed to increase when the TEAC's input<em> </em>voltage was increased. The TEAC's maximum exergy efficiency was 0.35, which was low compared to the coefficient of performance.

Cooling performance analysis of nanofluid assisted novel photovoltaic thermoelectric air conditioner for energy efficient buildings

• Novel radiator coupled nanofluid based thermoelectric air conditioning (NTEAC) system was developed. • Performance of the PV powered NTEAC system is analysed in a real time building of 25.6 m 3 size. • NTEAC system reduced the temperature of the test room below 22 °C with 6 A current. • Significant savings in power consumption and carbon emissions has been fortified. Carbon emissions and excessive power usage are addressed by applying thermoelectric cooling, which benefits from its ability to be portable, economical, and reliable. However, a conventional thermoelectric air conditioner's coefficient of performance (COP) is much less due to the sustained heat generated on the thermoelectric module's hot side. This work presents a novel idea of utilizing a nanofluid cooled radiator as an external cooling jacket around the thermoelectric module's hot side to enhance the heat transfer rate of thermoelectric air conditioners. In this research, the performance of a newly designed thermoelectric air conditioner (TEAC) powered by photovoltaic systems (PV) installed in a residential building is analyzed using nanofluid as a coolant. Furthermore, by supplying different input currents (2-6A), the cooling characteristics and performance of the newly designed nanofluid assisted thermoelectric air conditioner (NTEAC) system were experimentally studied in a test room of 25.6 m 3 volume in Malaysia's tropical climate. The system's best performance was at 6A, with a maximum temperature drop of 4.9 °C, a cooling capacity of 571 W, and a coefficient of performance of 1.27. In addition, the NTEAC system showed an energy saving of 67% and CO 2 emission mitigation of 76% when compared with a conventional split air conditioner. Thus, an alternative to the traditional air conditioning system was developed from this research, which is Freon free. This system is expected to consume less energy and emit less CO 2 for the tropical climatic conditions.

Design, Fabrication and Testing of Refrigerator System by Using Peltier Effect

The present air conditioning system produces cooling effect by refrigerants like Freon, Ammonia, etc. using these refrigerants can get maximum output but one of the major disadvantages is harmful gas emission and global warming. These problem can be overcome by using thermoelectric modules (Peltier effect) air-conditioner and their by protecting the environment. The present paper deals with the study of Thermoelectric air conditioner using different modules is discussed. Thermoelectric cooling systems have advantages over conventional cooling devices, such as compact in size, light in weight, high reliability, no mechanical moving parts and no working fluid.

Technical and economic analysis of a thermoelectric air conditioning system

The paper presents simulations of an air conditioning system based on thermoelectric modules. The proposed system is of a very simple structure, easy to control, scalable, noiseless, and harmless to the environment. The most important parameters that were to be changed were the number of modules, the electric current, and the size of the heat exchangers. The analyses were carried out for a commercially available thermoelectric module whose parameters were determined experimentally. The air conditioning system was analysed in terms of its cooling capacity and COP. Furthermore, it was optimized with economic criteria to achieve the highest cooling capacity of 1 dollar of total cost (electricity and investment) in a set period of device lifetime (ETCC – economic total cooling capacity). For 2400 h of device operation, at a temperature difference of 5 K and the average electricity cost in the EU, the optimized ETCC totals about 0.58 W/$. With the possibility of altering the inner geometry of the thermoelectric modules, the factor increased to 0.64 W/$. The test results showed that the device optimized in terms of ETCC did not operate with maximum cooling power and could be overloaded by about 30% in the reference working conditions.

Highly efficient thermoelectric air conditioner with kilowatt capacity realized by ground source heat-exchanging system

SummaryThe enormous need for refrigeration of modern human life has inevitably aggravated the environmental crisis worldwide. To date, there are very few refrigeration technologies available beholding both harmless refrigerants and high efficiency. Here, we proposed a geothermal-thermoelectric air conditioning system (GeoTEAC) with refrigerant-free and high energy efficiency through synergistically combining the merits of thermoelectric effect and ground source heat exchanging system. The system showed competitive cooling and heating COPs of 5.83 and 2.92, respectively, with kilowatt capacity, which are 3–4 times higher than that of previously reported thermoelectric air-conditioning setups. For a conceptual scenario, we demonstrated the lowest TEWI values for the GeoTEAC system among different air-conditioning types. Our work provides sustainable and climate-friendly solutions to realize worldwide emission peaks and carbon neutralization.

Performance Improvement of Thermoelectric Air Cooler System by Using Variable-Pulse Current for Building Applications

The thermoelectric air conditioning system (TE-AC) is a small, noiseless alternative to standard vapor compression refrigeration (VCR) systems. The cooling characteristics of a TE-AC system operating under two conditions, i.e., steady current and current pulses, are investigated in this study. This system consists of three thermoelectric modules, a heat sink, and an air circulation fan. The result shows that maximum temperature reduction in cooling side of TE-AC system was achieved at 6 A input current under steady state operation. The optimum performance of the TE-AC system under steady state operation depends upon the combined effect of the cooling load, Joule, Fourier, and Peltier heat. In TE-AC pulse operation, both current width and cooling load applied on the cold side of the thermoelectric module (TEMs) play an important role in achieving optimum cooling performance of the system. When normal input current operation (i.e., no current pulse) was compared to pulse-operated TE-AC system operation, it was found that pulse operation provides an additional average temperature reduction of 3–4 °C on the cold side of TEMs. Although on the hot side, it maintains a temperature in the range of 18 °C to 24 °C to reduce overshoot heat flux. The duration of operation is also important in determining pulse width and pulse amplitude. Minimum and overshoot peak temperature rises during each cycle for longer run operation. In the TE-AC system, the accumulated Joule heat during a current pulse frequently causes a temperature overshoot, which lasts much longer. As a result, the next current pulse was not released until the temperature of TE was restored to its initial value.

Optimization of the efficiency of permeable thermoelectric elements for air conditioner applicatons

The optimization of permeable thermoelement for thermoelectric air conditioner unit based is presented. In the thermoelectric air conditioner unit the air flow is cooled due to a combined action of thermoelectric effects and the Joule-Thomson effect. Methods for calculation of temperature distribution, determination of power conversion energy characteristics and thermoelement design in maximum COP mode are discussed. Results of computer studies for the case of thermoelement legs based on Bi2Te3 material have shown the possibility of COP increase by a factor of 1.6-1.7 as compared to conventional thermoelectric systems. 

Cost-Performance Trade-off in thermoelectric air conditioning system with graded and constant material properties

Thermoelectric (TE) air cooling is a solid-state technology that has the potential to replace conventional vapor compression-based air conditioning. In this paper, we present a detailed system-level modeling for thermoelectric air conditioning system with position-dependent (graded) and constant material properties. Strategies for design optimization of the system are provided in terms of cost-performance trade-off. Realistic convection heat transfer at both sides of the system are taken into account in our modeling. Effects of convection heat transfer coefficients, air flowrate, and thermoelectric material properties are investigated with varying key parameters such as TE leg thickness, module fill factor, and input current. Both constant material properties and graded properties are considered for the TE materials, and they are compared in terms of the degree of cooling, coefficient of performance (COP), and power consumption. For graded materials, we employ one-dimensional finite element methods to solve the coupled electrical and thermal current equations with arbitrary profile of material properties varying with position along the TE legs. We find that graded materials can enhance the degree of cooling, but only at the expense of COP, compared to the case of constant property materials. With constant material properties of ZT = 1 and relatively low electric current, the power consumption of TE coolers can be lower than those of conventional air conditioners at an equivalent cooling capacity. Considering additional advantages such as demand-flexible operation, low noise, and high scalability, thermoelectric cooling could be a competitive technology for future air conditioning applications..

Thermoelectric Power Generation: Harnessing Solar Thermal Energy to Power an Air Conditioner

We researched the feasibility of using thermoelectric modules as a power source and as an air conditioner to decrease reliance on fossil fuels. Thermoelectric modules have a “hot side” and a “cold side.” Based on the Seebeck Effect, when the hot side is heated, and the cold side is cooled, the module generates a voltage. Based on the Peltier Effect, when a voltage is applied to a module, the hot side becomes hot, and the cold side becomes cold. We constructed a “battery” using thermoelectric modules operating in the Seebeck Effect: solar thermal energy was used to heat the hot side, and tap water was used to cool the cold side to generate a voltage. The battery was then used to power a “thermoelectric air conditioner” made of one thermoelectric module operating in the Peltier Effect, where the cold side of the module absorbs ambient heat like a traditional air conditioner. We hypothesized that the battery would generate more power per square inch than a solar panel and that the thermoelectric air conditioner would operate without voltage regulation. The results showed that, at its peak, the battery generated 27% more power – in watts per square inch – than a solar panel, and the thermoelectric air conditioner operated despite an unsteady input voltage. The battery has incredible potential, especially if its peak power output can be maintained. However, the thermoelectric air conditioner is a viable alternative to commercial air conditioners only when space is an extreme limiting factor.