Ground-source heat pump systems (GSHPs) are extensively utilized due to their high efficiency and renewable energy characteristics. However, the complexity of factors affecting GSHPs loads poses significant challenges traditional data-driven methods in capturing the system's physical principles. Improving load predictive accuracy and generalizability remains a critical challenge. This study integrates GSHPs mechanism models into the CNN-ATT-LSTM framework, thereby developing the CNN-ATT-LSTM-Mechanistic model, which can enhance forecasting accuracy and generalization capability in complex conditions. The results demonstrate that the CNN-ATT-LSTM-Mechanistic model outperforms the CNN-ATT-LSTM, CNN-LSTM, and LSTM models in terms of MAE, RMSE, and R2. For instance, under the winter and summer conditions of Project A, as well as under the same conditions of Projects A and B, the model achieves a 20% improvement in these metrics, underscoring its robust predictive performance across the investigated case studies and its potential for transferability to similar GSHPs. The above indicates that effectively integrating physical mechanisms and data-driven methods is crucial for enhancing the accuracy and generalization of GSHPs load forecasting, significantly boosting its predictive performance and practical applicability under complex conditions.

The growing freshwater scarcity worldwide due to climate change, population growth, and uneven resource distribution, and fueling the demand for decentralized and climate-resilient water supply technologies. Atmospheric water harvesting leverages ubiquitous atmospheric moisture for freshwater supply but faces key limitations due to intermittent solar availability and insufficient water storage, especially during prolonged cloudy periods. Here, we report a hierarchical nanoporous membrane that integrates vapor adsorption, liquid water storage, and solar-driven release within a single material. Pore scale confinement enables strong capillary-driven adsorption and stabilization of moisture, while interconnected nanoporous pathways facilitate efficient water transport and reversible solar-driven desorption. This pore-mediated regulation overcomes the conventional trade-off between high water uptake and efficient release. As a result, our porous design achieved a water uptake of 8.07 g/g at 90% relative humidity, more than four-fold higher than that of the baseline architecture, while maintaining stable storage without performance decay. In outdoor tests, our membrane provided an average freshwater supply of 1.09 kg/(m2 & sdot;day), nearly doubling the baseline. Over one-month continuous operation, the promising porous membrane achieved a 154.11% increase in cumulative water production. When extrapolated to a global scale, the projected annual freshwater yield reaches 1.88 & times; 103 kg/m2, marking a 120.2% enhancement. Fabricated from cost-effective and environmentally friendly materials at a cost of 16.94 $/m2, we developed a robust porous architecture for continuous and resilient atmospheric water harvesting.

The construction industry, driven by the growing energy demands for heating, cooling, and lighting, accounts for nearly 40% of global energy consumption. It heavily relies on traditional materials such as Ordinary Portland Cement (OPC), whose production is energy-intensive and accounts for approximately 8% of global carbon dioxide (CO2) emissions. This study presents a multifunctional radiative cooling geopolymer (MRCG) as a promising and sustainable building material designed to address the aforementioned challenges. Prepared via an environmentally benign process, MRCG integrates thermal insulation and radiative cooling within a single material matrix. It exhibits a low thermal conductivity of 0.31 W/(m·K), significantly lower than that of conventional cement (1.13 W/(m·K)), while maintaining fire resistance and high compressive strength, supporting durable implementation in practical building applications. Meanwhile, MRCG delivers strong optical performance, with solar reflectance exceeding 93% and mid-infrared emissivity above 95%, enabling daytime subambient cooling of approximately 4.0 °C. Such cooling capability is expected to reduce HVAC electricity demand and thereby lower operational CO2 emissions in buildings. The modeling results demonstrate energy savings of up to 23% in hot climates when using MRCG, underscoring its regional adaptability and environmental benefits. By combining low thermal conductivity, high strength, and effective radiative cooling, MRCG provides a promising solution for future energy-efficient buildings, contributing to global carbon reduction goals.

While rooftop photovoltaics (PV) are pivotal for decarbonizing buildings, the energy interplay between bifacial PV systems and underlying roof materials, especially regarding their combined impact on building energy consumption and power generation across diverse climates, remains insufficiently explored. This study proposes an integrated optical-electrical-thermal modeling framework to evaluate bifacial PV systems on bare, radiative cooling, and green roofs across China. Results reveal that radiative cooling roofs achieve the highest annual PV power generation (up to 144.65 kWh/m2), enhancing output by 20-30% compared to bare roofs, while green roofs most effectively reduce heating, ventilation, and air conditioning (HVAC) energy consumption in most eastern regions. The comprehensive performance metric PV satisfaction rate for HVAC load (PSR-HVAC), shows that radiative coolers and green roofs can achieve near or full HVAC energy independence (up to 120%) in hot summer and warm winter regions and temperate regions, whereas conventional bare roofs peak at only 105.3%. This study provides architects and engineers with a validated decision-support tool for selecting regionally suitable roof-PV combinations, while offering policymakers science-based references for developing localized building energy codes.

Indoor volatile organic compounds (VOCs) severely impact air quality and human health. Metal-organic frameworks (MOFs), with high surface area, tenable structures, and excellent molecular recognition, show great potential in photocatalytic VOCs degradation. MOFs photocatalysts achieve efficient degradation via a “capture-mineralization” mechanism, offering low energy consumption and environmental benefits. However, commercialization faces challenges including high production costs, limited stability, and scale-up difficulties. Engineering applications require coordinated efforts in microscopic structural optimization, green synthesis, and system integration, alongside evaluation of degradation efficiency and safety under real conditions. Future advances combining high-throughput computation, machine learning, multifunctional photo-thermal/electrochemical devices, and integration with building HVAC systems will enhance the practicality and scope of MOFs photocatalysis. Developing cost-effective MOFs photocatalysts with rapid degradation, high adsorption capacity, and robust cycling stability is key to addressing indoor air pollution.

Water and electricity are fundamental resources for human survival and societal development. This work designs a photovoltaic and membrane distillation (PV-MD) system for the distributed co-production of power and freshwater by harvesting both solar radiation and PV waste heat. An integrated heat-mass-power transfer model is developed and experimentally validated, allowing for accurate performance prediction under various structural and environmental conditions. Parametric analysis identifies membrane thickness and PV efficiency as critical design factors, while solar irradiation and humidity are the dominat external influences. Energy flux analysis underscores the trade-off between freshwater production and power generation under varying operation conditions. Furthermore, the hybrid cooling configuration demonstrates superior performance over conventional heat sinks, enhancing freshwater yield by 24.64% and PV power output by 4.28%. For opyimally designed systems, climate-specific modeling across diverse representative climates demonstrates strong adaptability, achieving freshwater production gains of 0.54%-19.71% and PV power increase of 0.10%-1.06% compared to heat sinks. This study provides valuable insights into the power-water synergy within PV-MD systems and offers the targeted guidance for system-level design and performance optimization across diverse climates.

Indoor humidity strongly affects both building energy demand and occupant health in hot and humid climates, but it remains largely controlled by energy-intensive mechanical systems and is seldom exploited as a source of freshwater. Here, we demonstrate a passive humidity regulation and freshwater harvesting strategy enabled by cost-effective adsorption films (18.79$·m-2) that couple moisture capture, storage, and release within indoor environments. The films rapidly reduce relative humidity from 90.7% to 21.6% within one hour while maintaining long-term operational stability and release the captured moisture to produce freshwater at a rate of approximately 1.1 kg·m-2·day-1 under ambient conditions. Leveraging the harvested water, an autonomous plant irrigation system is achieved, enabling sustained regulation of indoor CO2 concentration (about 920.2 ppm) without manual intervention. Global-scale projections indicate that this passive approach could reduce building energy consumption by up to 29.9 kWh·year-1·m-2 and associated carbon emissions by 16.5 kg·year-1·m-2, with an exceptionally short payback period of 48 days. This work reframes indoor humidity from a latent load to a recoverable resource, offering an integrated route towards water harvesting, energy reduction and healthier indoor environments in sustainable buildings.

Building energy consumption accounts for 20%-40% of global energy usage, with windows among the least energy-efficient components. For this issue, thermochromic smart windows have emerged as a cost-effective, stimuli-responsive approach to enhance building energy performance. However, achieving long-term improvements in the indoor lighting environment remains a significant challenge for this technology. In this work, we developed a dual-responsive hydrogel that combines photochromic and thermochromic functionalities, exhibiting excellent shrinkage resistance, tunable spectral characteristics, and robust color-changing behavior. By integrating these hydrogels with solar selective and indium tin oxide films, we designed a tri-band regulation smart window featuring asymmetric mid-infrared emissivity, capable of simultaneously managing visible and near-infrared light to effectively reduce indoor heat gain and loss. The resulting smart window demonstrated superior spectral performance, with a solar modulation rate (ΔTsol) of 40.8%, visible light modulation (ΔTlum) of 61.4%, near-infrared blocking of 71.7%, and an emissivity contrast between the inner and outer surfaces (Δε) of 66%. These outstanding properties translate into annual energy savings of 14.2%-24.4% for curtain wall buildings globally, excluding polar regions. The concept of tri-band dual-response regulation significantly enhances the energy saving potential of smart windows and broadens their prospects for practical application.

Data center industry has become a rapidly growing electricity consumer, as cooling systems can account for 24-40% of total data center energy use. Improving cooling performance is therefore essential not only for thermal reliability and operational continuity, but also for reducing energy consumption and associated indirect carbon emissions, thereby supporting low-carbon operation and renewable-friendly demand response. Compared with conventional buildings, data center cooling systems exhibit stronger spatiotemporal coupling, multi-scale fault propagation, and stringent thermal constraints, which limits the direct transferability of traditional fault detection and diagnosis (FDD) methods. Despite the growing importance of these challenges, existing FDD reviews have mainly addressed conventional building HVAC systems or general diagnostic algorithms, leaving data center cooling FDD insufficiently synthesized as a distinct research problem. This review addresses this gap by synthesizing FDD methods, applications, and quantitative performance evidence in data center cooling systems. It compares knowledge-driven and data-driven approaches, including hybrid deep learning methods across five dimensions: modeling dependency, data requirement, interpretability, computational complexity, and energy/carbon impact measurability. Commonly used evaluation methods and metrics for fault detection and diagnosis are also summarized. Finally, five critical challenges are identified, and future directions are outlined toward knowledge-enhanced, multimodal, and self-evolving FDD systems that can support sustainable, reliable, and autonomous operation of next-generation intelligent data centers.

In response to the distinctly different heating load characteristics within heterogeneous building complex, traditional heating load allocation strategies based on fixed weights can no longer meet the requirements for energy conservation and improving indoor temperature satisfaction rates. This study addresses this problem by proposing an adaptive-weighted multi-objective reinforcement learning (Adaptive-Weighted MORL) framework for a heterogeneous building complex comprising a training gym, office building, dormitory, and cafeteria. The framework achieves dynamic balance optimization between heating load and thermal comfort through an adaptive weight adjustment mechanism integrating proximal policy optimization (PPO) algorithm and non-dominated sorting genetic algorithm II (NSGA-II). PPO learns optimal heating load allocation strategies to adapt to environmental changes, while NSGA-II generates Pareto-optimal solution sets to guide PPO’s weight coefficient updates. This mechanism dynamically adjusts the heating load weight and thermal comfort weight, prioritizing thermal comfort weight under extreme weather conditions. Results demonstrate that, compared to the PPO method and traditional fixed-weight approach, the proposed framework achieves an overall energy saving rate of 22.1

Thermoelectric Generators (TEGs) offer the green and sustainable solution to power shortages in remote areas. Their energy conversion efficiency can be significantly improved by maximizing the temperature difference between the hot and cold sides. This work introduced a novel TEG system, utilizing concentrated solar energy as the hot source and hybrid coolers combining radiative and evaporative cooling as the cold source. The effects of structural design and meteorological factors on hybrid cooling in TEGs were analyzed, and their application potential was explored, which has not been thoroughly investigated in previous literature. Results revealed that the thermal conductivity of hydrogels exhibited a significant role among structural parameters. Meanwhile, wind speed and backplate temperature markedly influenced the power output. Notably, hybrid coolers demonstrated global potential, particularly in low-and mid-latitude regions. In Senegal, a low-latitude region, hybrid coolers achieved an annual average temperature difference of 159.15 degrees C, enabling an annual output power of 5566.76 W/m2, a 13.6 % improvement over heat sinks. In high-latitude regions, lower ambient temperatures resulted in an annual average temperature difference below 90 degrees C, compromising power generation. Overall, the developed mathematical model provides valuable guidance for material design and paves the way for broader applications of hybrid cooling technology.

Maintaining a stable body temperature proves to be critical for human survival and functional capacity. However, conventional textiles exhibit significant limitations in preserving thermoregulatory microenvironments during dynamic climatic variations. Herein, we present a dual-mode textile (DMT) that combines radiative cooling and solar thermal harvesting technology to achieve year-round passive thermal regulation. The DMT cooling layer demonstrates an impressive performance with 96.1% solar reflectance and 92.0% mid-infrared emissivity. Under direct sunlight, it achieves an average temperature drop of 6.37 °C, corresponding to an average cooling power of 53.3 W/m2. In heating mode, its high solar absorptivity of 90% results in an average temperature increase of 16.3 °C compared to that of ambient temperature. Additionally, the DMT demonstrated excellent mechanical properties and water vapor permeability. Real-world wear tests of the DMT shows a 2.3 °C temperature reduction compared to that of a plain white cotton T-shirt, along with excellent heating performance. Furthermore, simulations indicate that the DMT could cool by ∼5 °C in the summer and insulate by ∼13 °C in the winter compared to conventional clothing. On the whole, this work enables dynamic thermal management across varying conditions, introducing possibilities in the rational design of next-generation smart textiles.

Radiative sky cooling has emerged as one of effective routes to counter the increasingly severe global warming and extreme weather. With worldwide efforts, this technology has witnessed significant advances in developing various cooling materials and implementing application attempts. However, the misconceptions of thermal conductance on cooling materials have significantly blocked the further breakthrough of this technology. This perspective aims to address this issue by elucidating the impact of thermal conductance on radiative cooling performance in two key applications: building cooling and personal thermal management. It is delved into the modulation of thermal conductance in cooling materials, focused on porous structures, heat-conductance structures, and tunable heat-conductance structures. Furthermore, the design principles for cooling materials is discussed, emphasizing low thermal conductance for building cooling and high thermal conductance for cooling textiles. To drive further breakthroughs in radiative cooling technology, challenges facing its implementation is highlighted and present this perspective on overcoming them.

To address the urgent need to reduce global carbon emissions and mitigate climate change, China has prioritized the promotion of ultra-low energy consumption green buildings as a key strategy for advancing national carbon neutrality goals. This study explores the critical role of ULEC buildings in supporting these goals by establishing a collaborative framework among the government (GOVT), green real estate developers (GRED), and housebuyers (HBs). Employing a tripartite evolutionary game model informed by current Chinese policies and regulations, this research simulates the dynamic interactions and stable strategies among these stakeholders. Our findings indicate that adjusting land purchase costs and implementing carbon emission fines effectively incentivizes government engagement in cooperative projects, with optimal land valuation identified between 800 and 850 $/m2 and carbon emission penalties between 28 and 32 $/t. Subsidies emerge as essential for encouraging active participation from GRED and HBs, yet careful calibration of subsidy levels is recommended to ensure sustainability. This study contributes valuable insights into policy formulation, highlighting actionable strategies to accelerate the development of ultra-low energy consumption green buildings as part of China's path to carbon neutrality.

Solution-processed photovoltaics hold great application potential in offsetting energy crisis and global warming. Organic hole transport materials (HTMs) have triggered the continued progress of solution-based solar cells, e.g., the promising quantum dot (QD) solar cells. Nevertheless, most organic semiconductors present the intrinsically low mobility, which greatly compromises efficient carrier transport. To counter this issue, we introduced the promising perovskite nanocrystals to modulate the electrical and molecular stacking properties of organic HTMs. With this strategy, the hole mobility was boosted from 5.0 x 10-5 cm2 V-1 s- 1 to 1.7 x 10-3 cm2 V-1 s- 1 with over 30-fold increase. Moreover, the introduction of perovskite nanocrystals can enable the favorable film morphology, face-on molecular orientation and the enhanced crystallization, which can accelerate carrier transport and reduce charge recombination in opto-electronic devices. With these benefits, the performance of QD/polymer solar cells was substantially enhanced from 11.1% to 14.1%, which was the topmost value in the field. More strikingly, QD/polymer photodetectors can also achieve the champion detectivity of -2.17 x 1013 Jones, with the 7-fold increase over that of the counterparts. More strikingly, the building carbon emission reduction with QD/polymer solar cells was further evaluated and the world map of CO2 emission reduction was presented for the first time.

Photovoltaic (PV) technology is essential for renewable energy systems. However, the persistent issue of hot spots poses a threat to the reliability and efficiency of PV systems. Conventional strategies often require circuit modifications, adding cost and complexity. In this work, a novel hydrogel-based cooling approach that effectively mitigates hot spots without altering circuits is introduced. This method can significantly improve power generation performance under both normal and hot-spot scenarios. Notably, the optimized hydrogel reduces hot-spot temperatures by 16.2 degrees C, outperforming conventional hydrogels (10.7 degrees C). This advancement boosts cooling power to 463.8 W m- 2, resulting in a notable 13% improvement in power output. Moreover, the hydrogels demonstrate superior durability, with reduced issues of cracking and shrinkage during prolonged operation. They exhibit a volumetric shrinkage of 34%, outperforming conventional hydrogels with a shrinkage rate of 46%. Modeling results indicate annual power generation increases of 7.0% in Singapore and 6.5% in Hong Kong, with estimated payback periods of 3.2 and 4.5 years, respectively. On a global scale, this cooling strategy has the potential to offset approximate to 50% of power generation losses caused by hot spots in building-integrated PV systems. This underscores the transformative potential of hydrogel-based cooling in advancing sustainable solar energy solutions.

"Range anxiety" has been one of the major constraints for the further development of electric vehicles (EVs). Air conditioning operation significantly increases energy consumption in EVs, thereby reducing the driving distance. In this work, we developed promising solar selective films based on the refractive index matching principle, combining solar regulation and radiative cooling. Spectral profiles indicate that solar selective films possess the exceptionally high visible-light transmittance of over 85 %, surpassing the transparency requirement for automobile windshields (70 %). Additionally, the selective films achieve a near-infrared blocking rate of 71.3 % and the mid-infrared emissivity of 94.8 %. These properties contribute to the significant reduction in interior temperature by 18.6 degrees C compared with no film and 8.8 degrees C compared with commercial film. Moreover, solar selective films can extend the onset of heatstroke by 21-75 min for rescue operations, when infants are inadvertently left in EVs. Moreover, the selective films can improve the endurance mileage of EV with panoramic sunroof by 48-62 km (10.6 % similar to 12.7 %) in different climatic zones (tropical, subtropical and temperate). Encouragingly, the selective films present the facile preparation process, excellent color fidelity, outstanding waterproof and cleanability, indicating the huge potential in reducing energy consumption and improving the endurance mileage of EVs.

With the increase in global climate warming and carbon dioxide emissions from air conditioning dehumidification, the impact of high indoor humidity on human health and building safety has become more pronounced. High humidity environments not only encourage the growth of mold and bacteria, thereby increasing the risk of respiratory diseases and allergic reactions, but also lead to the deterioration to building materials and household equipment. As a result, indoor dehumidification technology has garnered considerable attention in recent years. This review highlights recent advancements in utilizing adsorbent materials for indoor dehumidification and outlines the selection principles for developing high-performance dehumidification technologies. It compares and evaluates the development and performance of various adsorbent materials, emphasizing their respective advantages and limitations in indoor dehumidification technology. Moreover, the devices and systems of indoor dehumidification are further discussed to highlight their significant application potential for humidity control. Finally, this paper explores anticipated developments in indoor dehumidification technology with the aim to advance its commercial applications.

The efficiency and longevity of photovoltaics (PV) are sensitive to high operation temperatures, while their operational reliability can be compromised under winter conditions. Evaporative passive cooling can help control the temperature of PV by using hydrogels as water-rich materials. However, the lack of clear design principles and the uncertainty in ensuring the winter performance of PV in mid-to-high-latitude regions remain critical gaps. In this work, we establish the design principles for hydrogels with efficient and sustained evaporative cooling capabilities and demonstrate their application in enhancing PV performance across all seasons. The developed polyacrylamide (PAM) hydrogels can deliver a maximum temperature drop of similar to 27 degrees C and a peak cooling power of 612 W/m2 for PV heat dissipation. The developed hydrogels can alleviate snow accumulation and accelerate snow melting of PV panels in winter via vapor adsorption.

As a passive cooling technology with zero energy consumption and pollution, radiative cooling has shown huge energy saving potential. However, its application in building glass still faces great challenges due to the contradiction between transparency and cooling performance. In this work, we combined solar regulation and radiative cooling to develop promising solar selective films. Spectral analysis shows that the solar selective films presented an emissivity of 92.2% in the mid infrared band (8-13 mu m), a blocking rate of 78% in the near-infrared band (780-2000 nm), and an average transmittance of 63.7% in the visible band (400-780 nm), resulting in a considerable indoor temperature drop of 11 degrees C in summer. Meanwhile, energy consumption analysis demonstrated that the solar selective films can reduce the energy consumption of air-conditioning by 11.5-25% in different regions and the corresponding payback periods are only 0.16-0.72 years. More strikingly, the developed films presented a facile preparation process and superior stability, indicating their great application potential in reducing the energy consumption of buildings.