Trombe Wall Research Articles

Analysis of influencing factors on the performance of wavy-shape solar Trombe walls based on orthogonal experimental design and simulation methods

Analysis of influencing factors on the performance of wavy-shape solar Trombe walls based on orthogonal experimental design and simulation methods

Theoretical Analysis of a Novel Rock Wall to Limit Heating Demands in Historical Buildings

In the near future, the building sector will continue to absorb the greatest share of primary energy worldwide. It is necessary to find innovative solutions that promote energy efficiency through renovation measures, especially in historical buildings, for which refurbishment is constrained by several issues. In this study, we propose a novel Trombe Wall configuration that is easily integrable and based on a rock wall made of caged stone to use as a thermal accumulator. The system was investigated preliminarily using a transient Finite Difference Method (FDM) code to analyse the temperature field inside the rock wall. Successively, FDM results were employed as input data in TRNSYS simulations to determine the savings achievable in thermal heating requirements. The results demonstrated that the proposed solution, in the considered climate and on a reference historic building, can produce monthly heating savings varying between 26% and 85%. So, the rock wall results in a reliable solution for buildings in which refurbishment is difficult, allowing for preserving aesthetic features and improving energy efficiency by rationally using solar radiation.

Preparation and Performance Study of CaCl2 Composite Adsorbent Based on Rock Wool Board Suitable for Continuous Heat Storage/Release of Trombe Wall

Preparation and Performance Study of CaCl2 Composite Adsorbent Based on Rock Wool Board Suitable for Continuous Heat Storage/Release of Trombe Wall

Parametric and optimization analyses of a dynamic trombe wall incorporating PCM to save heating energy under cold climate zones

The Trombe wall system incorporating a dynamic PCM layer (DTWPS) has been recognized as a viable envelope to reduce the energy demand for heating effectively. However, properly selecting PCMs in the DTWPS is complicated and much less studied. Therefore, parametric and optimization analyses of the PCM thermal properties of a DTWPS are carried out for heating energy saving under cold climate zones using a validated CFD model, multiple linear and nonlinear regression models, and the particle swarm optimization (PSO) algorithm. The results show nonlinear relationships between the four critical PCM thermal properties and the energy saving, time lag, and thermal comfort. Moreover, the optimal values of the melting point, latent heat, density, and thermal conductivity of the PCM are 26.4 °C, 200 kJ/kg, 2080 kg/m3, and 1.34 W/(m·K), respectively. Meanwhile, the energy saving for the test room equipped with the DTWPS with optimal thermal properties could reach 100 % compared to that for the traditional reference Trombe wall. With available PCMs, heating energy consumption can be saved by up to 90 % or more. Further, the DTWPS demonstrates a reduced PCM mass compared to other passive walls.

Passive Ventilation of Residential Buildings Using the Trombe Wall

The article explores passive systems for regulating microclimates in residential settings, with a focus on modular constructions. It investigates the use of the trombe wall system for passive ventilation to ensure comfort and hygiene. The study examines building designs that enable effective air circulation without using mechanical systems. Furthermore, the effectiveness of the passive system of using solar energy with the trombe wall as a ventilation device in modular houses has been experimentally confirmed. Although the research confirms the effectiveness of this solar system in modular homes, there is limited documentation regarding its overall efficiency, particularly concerning the impact of the surface pressure coefficient on ventilation. The study establishes the correlations governing the thermosiphon collector’s effectiveness at varying air layer thicknesses. Optimal parameters, such as maximum air consumption (L = 120 m3h−1), are identified at an air layer thickness (δ) of 100 mm and outlet openings area (F) of 0.056 m2. These findings pave the way for improving passive systems aimed at maintaining optimal thermal and air conditions in modern homes. The findings suggest the potential for more efficient and sustainable housing solutions. Further research is essential to understand how factors like building design and wind speed affect ventilation system efficacy.

CFD analysis of the impact of air gap width on Trombe wall performance

AbstractIn recent years, there has been a lot of research and debate on how solar energy can be used instead of conventional sources of heating to power residential heating. In this study, the Trombe wall (TW) technique, based on natural convection and energy storage, was examined to predict mass flow rate, temperature field, and velocity field for the TW system under steady conditions. A numerical simulation model was investigated for further validation using k‐ε turbulence and discrete ordinates (DO) radiation models. Independent grid studies were conducted to ensure that there were no changes after varying the grid numbers. The effect of the air gap was carried out to enhance TW thermal performance. CFD simulation shows good agreement with published data in the literature, and the optimum air gap was set at 0.1 m. The results pave the way for future studies to improve passive solar heating systems, which will eventually help move towards more sustainable residential heating solutions.

Prediction of room temperature in Trombe solar wall systems using machine learning algorithms

A Trombe wall-heating system is used to absorb solar energy to heat buildings. Different parameters affect the system performance for optimal heating. This study evaluated the performance of four machine learning algorithms—linear regression, k-nearest neighbors, random forest, and decision tree—for predicting the room temperature in a Trombe wall system. The accuracy of the algorithms was assessed using R² and RMSE values. The results demonstrated that the k-nearest neighbors and random forest algorithms exhibited superior performance, with R² and RMSE values of 1 and 0. In contrast, linear regression and decision tree showed weaker performance. These findings highlight the potential of advanced machine learning algorithms for accurate room temperature prediction in Trombe wall systems, enabling informed design decisions to enhance energy efficiency.

Experimental and simulation study of the effect of temperature and air supply on energy performance of a temperature-controlled ventilated double-layer Trombe wall

To study the energy performance of the temperature-controlled ventilated double-layer Trombe wall system (TCVD-TW) during winter and summer seasons, experiments and simulations were conducted in an experimental room in Qingdao where the system was installed. The experimental results demonstrate that the rooms equipped with this system exhibit favourable temperature performance in both winter and summer, with a positive impact on indoor humidity during the summer. The simulation results show that the performance of TCVD-TW is mainly affected by the supply air temperature, air volume flow rate, and indoor cooling and heating setpoints. For winter operating mode, the optimal supply air temperature setting should be 1°C higher than the heating setpoint. When the supply air temperature was set to 19℃(with a heating setpoint of 18 °C) and 21 °C (with a heating setpoint of 20 °C), the energy efficiency increased by 35.96 % and 32.38 %, respectively. When the supply air volume flow rate was set to 234 m3/h, the energy efficiency increased by 35.09 % (with a heating setpoint of 18 °C) and 30.27 % (with a heating setpoint of 20 °C), respectively. For summer operating mode, the optimal supply air temperature setting should be 1 °C lower than the cooling setpoint. When the supply air temperature was set to 25 °C (with a cooling setpoint of 26 °C), the energy efficiency improved by 33.62 %. When the supply air volume flow rate was set to 156 m3/h, the energy efficiency increased by 31.18 %. The experimental and simulation results of this study provide data support for the application of TCVD-TW.

The performance of a photovoltaic Trombe wall combined with phase change materials under climate change in Mashhad

Passive solar systems can be integrated with conventional buildings to reduce energy consumption. Various solutions are employed to enhance the performance of these systems. This study investigates the effectiveness of a photovoltaic (PV) Trombe wall combined with phase change materials (PCMs), taking into account climate change in Mashhad. The research is conducted through simulations. By altering the placement of PV cells and experimenting with different PCMs, the optimal performance of the Trombe wall was identified for both cold and hot periods of the year. The findings indicate that utilizing PV cells on glass with C18 PCM on the wall yields the best performance throughout the year. The highest indoor air temperatures recorded in April were 27.09 °C for the brick and 27 °C for the concrete Trombe wall. It was observed that the Trombe wall without PVs and PCMs absorbs more heat. Under the RCP2.6 scenario, the proposed Trombe wall is projected to remain efficient for the next 70 years. Study of RCP2.6 and RCP8.5 scenarios revealed that during both cold and hot periods of the year, thermal comfort provided by the Trombe brick wall surpasses that of the concrete wall, which is −0.261 and −0.322 in July.

Numerical and Experimental Study on the Performance of Photovoltaic—Trombe Wall in Hot Summer and Warm Winter Regions: Energy Efficiency Matching and Application Potential

Enhancing the energy efficiency of building envelopes is one of the key strategies for energy conservation and reducing consumption in buildings. This study employs numerical research methods to explore the impact of crucial factors such as solar cell coverage, air channel height, indoor relative humidity, and indoor wind speed on the power generation performance and thermal comfort of a photovoltaic (PV)—Trombe wall. The dynamic changes in optical and thermal performance and energy efficiency matching mechanisms of this system are also discussed in hot summer and warm winter regions. The research findings indicate that the periods of good thermal comfort and power generation efficiency for humans are from 9:00 to 17:00 in winter. In summer, these periods are from 5:00 to 8:00 as well as from 17:00 to 20:00. When the system height is 2 m, the electricity price for power supplied by the PV—Trombe wall system is 25% lower than the residential price, with an annual energy generation of 322.5 kWh/m2 of solar panel, which can save USD 6.35 in costs. Moreover, an experiment is conducted to investigate the thermoelectric correlation by constructing a traditional Trombe wall and an external PV—Trombe wall. When the coverage reached 52.08%, the overall system efficiency was maximized. At a coverage of 78.12%, the system’s thermal efficiency was at its lowest, while the maximum power generation was 510.3 W. It can be seen that the PV—Trombe wall possesses good economic benefits and energy saving as well as emission reduction potential in hot summers and warm winters regions, and the smooth implementation of related works will effectively promote its applications and promotions.

Optimized load vector regression for load prediction and improvement using trombe walls in household electrical energy consumption

Optimized load vector regression for load prediction and improvement using trombe walls in household electrical energy consumption

Investigation of the performance of a newly designed solar chimney for enhancing natural ventilation and mitigation of summer overheating

The significant challenge encountered in utilizing Trombe walls for winter heating is summer overheating, which limits the overall feasibility of the system. In response to this issue, the present study introduces a novel model of a Trombe wall-solar chimney system designed to enhance natural ventilation and address the problem of summer overheating. To assess the performance of the proposed model, a full-scale experimental test rig is constructed in Kirkuk, Iraq. This rig comprises a test room integrated with a Trombe wall-solar chimney system. Additionally, a numerical simulation based on the CFD approach along with a computer code is developed to investigate the behavior of the system. System analysis is conducted for the period August 14th–15th. The parameters studied include chimney height (ranging from 0.0m to 2.0m in 0.5m increments), chimney width (0.2m, 0.3m, 0.4m, and 0.5m), room inlet vent height (ranging from 0.2m to 0.4m with 0.05m increments), and chimney inlet vent height (ranging from 0.2m to 0.4m with 0.05m increments). The results highlight the crucial role of the massive storage wall in sustaining nighttime ventilation in the absence of solar energy by utilizing stored heat to warm the air and maintain the ventilation process. The study establishes that chimney height and width significantly influence airflow rate, while other factors have marginal effects. An empirical equation is formulated to predict the 24-h averaged air changes per hour (ACH), which is a critical measure of system performance in ventilation. This equation is developed using artificial neural network (ANN) techniques. Finally, the findings indicate that the suggested model effectively reduces summertime overheating while generating a satisfactory ventilation rate. This enhances the overall versatility and year-round usability of Trombe wall systems, making them more adaptive and efficient in regions with diverse climatic conditions.

Heating and energy performances of a dynamic Trombe wall incorporating phase change materials under different operation modes

Dynamic Trombe wall incorporating PCMs (DTWP) is promising for effectively utilizing solar energy and latent heat storage to achieve building energy saving and different operating modes of the DTWP have different functions corresponding to different thermal and energy performances. However, the suitable operation mode for this system is still unclear. Therefore, in this research, the heating and energy performances of the DTWP system with different operation modes and companion static concrete and PCM Trombe walls under a typical winter day in a cold climate were comprehensively investigated using the corresponding CFD model validated by experimental data. The main results are: (1) The DCNC mode(fully closed vents of the thermal storage wall during daytime and nighttime) showed significant decreases in heat loss and good heating performance for the DTWP system; (2) The DCNC mode could extend the time lag and the thermal comfort duration, and showed significantly improved energy saving by 97.6 %; (3) Compared to the DONO mode (opened vents of the thermal storage wall during daytime and nighttime), the DCNC mode could decrease the indoor temperature stratification by 53.7 % and 67.7 % at noon and midnight, respectively; (4) The air velocity near the outer surface of the energy storage wall and the inner surface of the glazing layer is higher than in the other regions at noon and midnight, respectively. The findings would provide guidance for the application and practical operation optimization of DTWP in cold climate regions.

Structure and regional optimization of a phase change material Trombe wall system

Trombe walls (TW) have been an effective passive solar technology for enhancing building energy efficiency. Considering the thermal storage and regulation capabilities of phase change materials (PCM) in solar energy utilization, TW with PCM (PCMTW) were designed and optimized to further improve building energy performance. This study investigated the combined effects of PCM phase change temperature, PCM location and ventilation strategies on a single-layer PCMTW. Moreover, a novel double-layer PCMTW was proposed and evaluated across various climate regions of China in consideration of the effect of PCM phase change temperature combinations. Results show that the single-layer PCMTW with PCM22 placed next to inner surface and ventilation achieved the lowest annual energy consumption. The selection of PCM phase change temperature was crucial for various climatic conditions. Compared to the traditional building, the highest heating energy-saving was 118.16 kWh/m2 achieved in Changchun with PCM22 + 28, and the highest cooling energy-saving was 45.71 kWh/m2 achieved in Haikou with PCM25 + 28. Additionally, the double-layer PCMTW was recommended for climate regions where the daily average temperature and the daily average solar emissivity were 20–25 °C and below 4 kWh/m2 in summer, and below 10 °C and 2–6 kWh/m2 in winter.

Thermal performance of a novel Trombe wall enhanced by a solar energy focusing approach

The Trombe wall is a passive solar building exterior wall system proposed by Professor Felix Trombe in France, which can collect solar energy to heat buildings without additional energy consumption, making it a focal point of research in building energy conservation. However, its effectiveness is constrained by the low density of solar radiation in winter and the potential for overheating in summer. This study introduces a novel Trombe wall designed to address these issues through a focused strategy, enabling automatic transition between heating during winter and shading during summer. The thermal performance parameters of the novel Trombe walls in both winter and summer seasons are examined, and their energy consumption is assessed using experimental research methodologies. Findings indicate that the novel Trombe wall facilitates greater energy savings in both winter and summer. When compared with traditional Trombe walls, the novel Trombe wall achieves a significant reduction in energy consumption, with up to 55 W/m2 in heating load during winter and 47 W/m2 in cooling load during summer. The introduction of this new system holds substantial potential for the realization of zero-energy buildings.

Multi-Aspect Shaping of the Building’s Heat Balance

In the European Union, buildings account for 42% of the energy consumption and 36% of the direct and indirect energy-related greenhouse gas emissions. Reducing thermal power for heating purposes is crucial to achieve climate neutrality. The main purpose of this article is to identify the places in the building where it is possible to significantly improve energy efficiency through the use of appropriate construction and material solutions. This article contains a multi-aspect approach to the heat balance of a building. Solutions that have a direct impact on building energy consumption were analysed, taking into account architectural, technological, and material aspects. Particular attention was paid to energy-efficient design and material solutions for non-transparent and transparent external walls and thermal storage walls (Trombe walls). An analysis of heat transfer through building elements was carried out, along with the optimisation of energy-efficient solutions for non-transparent and transparent barriers. Two methods for determining the equivalent heat transfer coefficient Ue for solar active partitions are presented. The analysis presented in the work using the original method of the balanced heat transfer coefficient Ue is a testing ground for identifying unfavourable features of the building structure, as well as the most energy-efficient solutions that can be used in establishing standards for the construction and modernisation of buildings. The value of the Ue coefficient illustrates the actual heat transfer through the partition. Having Ue values for various structural solutions of building envelopes, the designer can easily select the most effective ones. The use of the presented methodology will allow for the optimisation of technical solutions for building elements to improve its energy efficiency.

Performance evaluation of Trombe wall systems in enhancing thermal comfort in residential buildings of Subtropical highland climate - A case of Hamirpur, Himachal Pradesh, India

Performance evaluation of Trombe wall systems in enhancing thermal comfort in residential buildings of Subtropical highland climate - A case of Hamirpur, Himachal Pradesh, India

Performance prediction of a novel disinfection-enhanced type Trombe wall with transverse fins

Trombe wall is an efficient passive solar heating system, while the utilization form of heated air needs to be expanded. Indoor microorganisms that can be transmitted through aerosol endanger the safety of human health. The fact that microorganisms can be thermally inactivated makes it possible to disinfect the air through Trombe wall. To expand and enhance the disinfection effect of the wall, extending the residence time of bioaerosols in the flow channel and raising the air temperature can be applied. Therefore, a transverse-finned-Trombe wall is proposed. Multiple physical field coupling is studied numerically. Migration, inactivation, and deposition of bioaerosols are described by Eulerian method. The results indicated as follows: As fin height increases, the thermal efficiency first rises and then drops; the single-pass inactivation ratio rises remarkably with its value reaching 90.96 % and 66.98 % for SARS-CoV-1 and SARS-CoV-2 even at low irradiance level (400 W/m2) at a fin height of 35 mm. As fin angle increases from −45° to +45°, the thermal efficiency drops first and then rises. Optimal disinfection performance is achieved at α = 0°. The contribution of deposition to removal of infectious bioaerosols plays a significant role when the thermal inactivation is not strong.

Efficiency Assessment on Roof Geometry and Trombe Wall Shape for Improving Buildings’ Heating Performance

It is crucial to consider structural design issues in Trombe wall (T-wall) buildings to promote more suitable indoor climates and thermal comfort standards. Therefore, the present study examined the impact of two different T-wall designs and six different roof types on the energy and operational efficiency of a building located in a low-temperature and high-humidity winter climate. Ansys-CFX 15.0 software was employed to simulate the thermal and fluid dynamics behavior of the T-wall system, and flow, thermal comfort, energy, and exergy analyses were conducted. Three-dimensional simulation results and the pertinent literature data showed a good level of agreement, and the accuracy of the model was ensured. Outcomes revealed an average air velocity variation of 0.186 m/s and maximum average indoor air temperature variation of 3.3 °C between the six roof geometries. The highest air speed (0.988 m/s) was recorded for the gambrel roof while the lowest one (0.802 m/s) was recorded for the typical flat roof. The shed roof right with a rounded T-wall was more comfortable for standing and sitting activity than the others for the two T-wall shapes, and, at Y = 0.6 m and Y = 1.1 m, the average predicted percentages of dissatisfied (PPD) values were 31 and 28%, respectively. Furthermore, it was determined in the study that solar radiation intensity and T-wall and roof geometries had a significant effect on energy and exergy efficiency, and high energy and exergy efficiencies were achieved at higher solar intensity values. The best energy and exergy efficiencies were obtained for the butterfly and shed roof configurations. This study can serve as a reference for the thermal environment design of buildings with T-walls.

Energy efficiency of ecological buildings in Tunisia: Natural fiber composites and passive strategies impact

Improving the thermal insulation and energy efficiency of building envelopes is a major objective worldwide and has significantly developed in the recent years. This study aims to evaluate the impact of ecological additive and passive strategies on building energy efficiency. An experimental study was carried out to examine the effect of the incorporation of treated Alfa and Posidonia-Oceanica fibers on the thermal properties of cement and gypsum composite samples. The experimental results were then introduced in a numerical study using TRNSYS software to perform a comparison of the energy efficiency and thermal performance of three individual buildings; two ones constructed with our ecological materials and the third one with typical materials is considered as a reference case under the Tunisian climate. The obtained results indicate that the buildings built with Alfa fibers (BAF) and Posidonia-Oceanica fibers (BPOF) are economically effective since they allow a decrease of about 48.20% and 43.48% in heating, 45.71% and 42.77% in cooling, leading to a reduction in CO2 emission of 47.90% and 43.40%, respectively, in comparison with the reference case. The investigation also focuses on the improvement of the ecological building envelope by a storage wall integrated on the south front and shaded by solar movable overhangs during the summer season. The indoor climate results reveal that incorporating passive strategies into the building improves indoor air temperature and preserves a comfortable indoor relative humidity. Heating requirements decrease by 82.82% for BAF and by 79.76% for BPOF. The cooling requirements of the reference building are also reduced by 63.46% for BAF and 60.45% for BPOF by the use of natural night ventilation (4 ACH) and the appropriate shading for Trombe walls and windows. Consequently, the implementation of passive strategies on the ecological buildings led to a net reduction in CO2 emissions by up to 80.55% for BAF, compared to the reference case.