M. N. Abd-Al Ameer, Iman S. Kareem, Ali A. Ismaeel^*

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.073437 - 27 December 2025

Abstract Electrical and electronic devices face significant challenges in heat management due to their compact size and high heat flux, which negatively impact performance and reliability. Conventional cooling methods, such as forced air cooling, often struggle to transfer heat efficiently. In contrast, thermoelectric coolers (TECs) provide an innovative active cooling solution to meet growing thermal management demands. In this research, a refrigerant based on mono ethylene glycol and distilled water was used instead of using gases, in addition to using thermoelectric cooling units instead of using a compressor in traditional refrigeration systems. This study evaluates the… More > Graphic Abstract

Najiba Hasan Hamad^1,*, Ranj Sirwan Abdullah², Ahmed Mohammed Adham²

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.073377 - 27 December 2025

Abstract Coiled tube heat exchangers are widely preferred in shell structures due to their superior heat transfer performance, driven by favorable flow characteristics. This study investigates the effect of modifying coil and shell configurations on heat transfer efficiency. Two key enhancements were examined: adding fins to the outer coil surface and integrating longitudinal slots within a hollowed shell. These modifications promote turbulence and extend heat transfer duration, thereby improving performance. However, they also introduce challenges, including increased pressure loss and manufacturing complexity. Numerical simulations were conducted using ANSYS Fluent 2024R1 under identical boundary conditions. With a… More > Graphic Abstract

Y.C. Rodríguez-Gómez¹, J. Serrano-Arellano^1,*, F.N. Demesa-López¹, J.M. Belman-Flores², J.F. Ituna-Yudonago³

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 2073-2107, 2025, DOI:10.32604/fhmt.2025.069564 - 31 December 2025

Abstract The Trombe Wall (TW) is a low-cost, passive heating system known for its high thermal efficiency, particularly in cold and temperate climates. Recent research has explored its adaptability to warm-dry climates with high thermal variability, such as those found in central Mexico. This study presents a dynamic simulation-based analysis of the TW’s thermal performance in a representative social housing unit located in Pachuca de Soto, Hidalgo. Two models were compared—one with a south-facing TW system and one without—to evaluate indoor thermal comfort throughout a full annual cycle. The simulations were conducted using OpenStudio and EnergyPlus,… More > Graphic Abstract

S. Srinivasa senthil, K. Vijayakumar^*

Energy Engineering, Vol.122, No.12, pp. 5149-5173, 2025, DOI:10.32604/ee.2025.070889 - 27 November 2025

Abstract Heating, ventilation, and air conditioning (HVAC) systems contribute substantially to global energy consumption, while rejecting significant amounts of low-grade heat into the environment. This paper presents a non-intrusive spiral-coil heat exchanger designed to recover waste heat from the outdoor condenser of a split-type air conditioner. The system operates externally without altering the existing HVAC configuration, thereby rendering it suitable for retrofitting. Water was circulated as the working fluid at flow rates of 0.028–0.052 kg/s to assess thermal performance. Performance indicators, including the outlet water temperature, heat transfer rate, convective coefficient, and efficiency, were systematically evaluated.… More >

Tao Lin^1,*, Chengdai Chen¹, Liyao Chen¹, Fengqin Han¹, Guanghui He²

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1661-1680, 2025, DOI:10.32604/fhmt.2025.070787 - 31 October 2025

Abstract Targeting spontaneous coal combustion during stacking, we developed an efficient heat dissipation & self-supplied wireless temperature measurement system (SPWTM) with gravity heat pipe-thermoelectric integration for dual safety. The heat transfer characteristics and temperature measurement optimization of the system are experimentally investigated and verified in practical applications. The results show that, firstly, the effects of coal pile heat production power and burial depth, along with heat pipe startup and heat transfer characteristics. At 60 cm burial depth, the condensation section dissipates 98% coal pile heat via natural convection. Secondly, for the temperature measurement error caused by… More >

Basima Salman Khalaf^*, Abeer H. Falih, Basim Freegah

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 943-956, 2025, DOI:10.32604/fhmt.2025.065366 - 30 June 2025

Abstract The main purpose of this research is to optimize the hydrothermal performance of a dimpled tube by augmenting the surface area for heat transmission and thermal layer cracking. To achieve that, the impact of different dimple diameters and their distribution along the dimpled tube was investigated numerically using the ANSYS Fluent 2022 R1 software by considering two models, A and B. Both models consist of three regions; the first, second, and third have dimple diameters of 3, 2, & 1 mm, respectively. Model A included an in-line dimple arrangement, while model B involved a staggered… More >

Ans Ahmed Memon¹, Laveet Kumar^1,2,*, Abdul Ghafoor Memon¹, Khanji Harijan¹, Ahmad K. Sleiti²

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 833-856, 2025, DOI:10.32604/fhmt.2025.064805 - 30 June 2025

Abstract Climate change, rising fuel prices, and fuel security are some challenges that have emerged and have grown worldwide. Therefore, to overcome these obstacles, highly efficient thermodynamic devices and heat recovery systems must be introduced. According to reports, much industrial waste heat is lost as flue gas from boilers, heating plants, etc. The primary objective of this study is to investigate and compare unary (Al₂O₃) thermodynamically, binary with three different combinations of nanoparticles namely (Al₂O₃ + TiO₂, TiO₂ + ZnO, Al₂O₃ + ZnO) and ternary (Al₂O₃ + TiO₂ + ZnO) as a heat transfer fluid. Initially, three different types of… More > Graphic Abstract

Walaa M. Hashim, Israa S. Ahmed, Ayad K. Khlief^*, Raed A. Jessam, Ameer Abed Jaddoa

Energy Engineering, Vol.122, No.6, pp. 2485-2501, 2025, DOI:10.32604/ee.2025.061630 - 29 May 2025

Abstract Achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge since the absorption peaks of common metal particles are usually located in the visible part of the radiation spectrum. This paper aims to present the results of experimental investigations on the thermal performance of heat pipe-type evacuated solar collectors. The experimented system consists of 15 tubes, providing the hot nanofluid to 100-L storage in a closed flow loop. The solar collector with a gross area of 2.1 m² is part of the solar hot water test system located in Baghdad-Iraq. Al₂O₃ nanofluid at… More >

Zainab Mahdi Saleh^1,*, Riyadh S. Al-Turaihi¹, Zena Khalefa Kadhim²

Frontiers in Heat and Mass Transfer, Vol.23, No.2, pp. 615-650, 2025, DOI:10.32604/fhmt.2025.063404 - 25 April 2025

Abstract This study involved numerical simulations of a double tube heat exchanger using the ANSYS FLUENT program version 22. The study aims to examine methods for minimizing pressure loss and consequently enhancing the thermal performance index (TPI) of a heat exchanger fitted with wavy edge tape that is a heat recovery system (the hot air in simulation instead of t heat from the exhaust gases of the brick factory furnaces and return it to warm the heavy fuel oil by substituting the electrical heater with a heat exchanger to recuperate waste heat from the flue gases,… More >

Yuze Xue¹, Li Kou^2,3, Guosheng Jia^4,*, Liwen Jin⁴, Zhibin Zhang⁴, Jianke Hao⁴, Lip Huat Saw^5,*

Energy Engineering, Vol.122, No.3, pp. 1005-1024, 2025, DOI:10.32604/ee.2025.059198 - 07 March 2025

Abstract Geothermal energy, a form of renewable energy, has been extensively utilized for building heating. However, there is a lack of detailed comparative studies on the use of shallow and medium-deep geothermal energy in building energy systems, which are essential for decision-making. Therefore, this paper presents a comparative study of the performance and economic analysis of shallow and medium-deep borehole heat exchanger heating systems. Based on the geological parameters of Xi’an, China and commonly used borehole heat exchanger structures, numerical simulation methods are employed to analyze performance and economic efficiency. The results indicate that increasing the… More > Graphic Abstract