Insulation Level Research Articles

A simple dynamic time constant model for both summer overheating and winter heating analysis

As new buildings have high levels of insulation it is important to ensure that solar and other internal gains do not make the interiors too hot in summer. This is well known. But assessing overheating at an early design stage is not so easy. The Thermal Mass Parameter (TMP) in the regulations is based on a 24 h cyclic assessment of the depth of heat storage in a material. This paper examines a simpler method using the whole thermal mass, simple steady state calculations and a time constant that can take into account the heat gains over a number of days, such as in a heat wave, not just over 24 h. This simple dynamic time constant model (SDTCM) would be a more realistic model to assess overheating and performance for Future Homes and Buildings Standards, now under consultation in the UK. The model can equally be applied to assess winter heating and for dynamic simulation to consider control strategies. Practical application This paper describes a simple model that can be used for determining heating sizing in winter and overheating in summer. It relates to assessing the thermal mass via the time constant relating to the dynamic response of the building. This will be useful in initial design and possibly regulation.

Effects of honeycomb panel's finite dimensions on acoustic performance for lightweight sound insulation

A honeycomb panel is considered as a lightweight sound insulation solution both numerically and experimentally. First, a unit cell with fixed and infinite periodic conditions is modeled, exhibiting high insulation levels up to the membrane's eigenfrequency. Closer to industrial applications, a numerical model is developed, where the fixed conditions are applied only on the sides of the finite honeycomb panel. Taking into account structural modes of longer wavelength with this configuration, the panel's first eigenfrequency occurs at lower frequency than the previous case, yielding to a reduced insulation power. Nevertheless, the low frequency performance obtained numerically on the honeycomb panel is validated with measurements under normal incidence plane waves and diffuse field excitations.

Building retrofitting towards net zero energy under climate change

Abstract The challenge in Net-Zero Energy Building (NZEB) retrofitting is to identify the most effective measures to address energy performance issues. This paper presents a machine learning model for optimizing retrofit measures to achieve NZEB under the influence of climate change. Specifically, the non-dominated sorting genetic algorithm (NSGA-III) minimizes energy consumption and the predicted percentage of dissatisfaction (PPD) while achieving a NZE balance, thereby obtaining the Pareto front. The Order of Preference by Similarity to Ideal Solution (TOPSIS) ranking technique is then applied to the Pareto front to obtain an optimal solution. Various passive energy retrofit measures are investigated, and renewable retrofit measures are employed to cover the required energy. This process is repeated for different time frames to consider the impact of climate change on selecting retrofit measures. The results clearly indicate that, for retrofitting a residential NZEB, higher insulation values are needed for future scenarios compared to the present scenario due to the effects of climate change. Using the future scenarios defined by the Shared Socioeconomic Pathways framework, a higher level of envelope insulation and renewable retrofit measures are required to achieve NZEB in the Sustainable Future scenario compared to the Fossil Fuel-dependent Future scenario, with increases of 35% and 50%, respectively.

Performance Evaluation of Low Thermal Bridging Drywall System with Separating Clips for C-Studs

Drywall systems comprising gypsum boards and steel C-studs are widely used due to their lightweight structure, rapid construction, and ease of installation. These systems must meet the required thermal insulation performance for their specific applications. However, metal C-studs penetrate the insulation layer at intervals, leading to additional heat loss, reduced thermal insulation performance, and lower indoor surface temperatures, which can result in condensation and mold growth. To address these issues, this study proposes a drywall system with low thermal bridging studs made up of two small-sized studs and four or five separating clips made of reinforced plastic. These clips separate the studs to minimize heat transfer through metal elements, maintain structural stability despite the spacing between them, and facilitate easy assembly. The results from mock-up tests showed that the proposed system’s thermal transmittance was 0.370 W/m2K, which is 28.8% lower than the 0.52 W/m2K observed with conventional C-studs. The proposed drywall system also met Korean regulations for acoustic insulation level 3 and the 2 h fire resistance criteria, similar to existing drywall systems with conventional C-studs. Moreover, the maximum and residual displacements were within an acceptable range for a horizontal load of 3000 N applied vertically to the non-load-bearing wall. Building energy analysis indicated that using the proposed drywall adjacent to unconditioned spaces could reduce the annual heating and cooling load by 2.5–3.0%, despite a 1.5–1.9% increase in the annual cooling load. The annual heating load decreased by 4.8–5.9% under infiltration rates of 0.5 to 1.5 air changes per hour for adjacent unconditioned spaces, making this drywall system’s improved insulation quality crucial for achieving heating-dominant zero-energy buildings.

Geopolymer-based insulated wall incorporating construction and demolition waste: Experimental assessment of thermo-physical behavior

The benefit of the application of geopolymers in the building sector is nowadays undisputed. In addition to good structural characteristics, these are characterized by interesting thermophysical properties, obtained through a production process, that reduces CO2 emissions and could incorporate recycled material, thus responding to environmental sustainability. However, it is noted the lack of studies regarding the in-field thermal performance. Thus, the aim of the present study is to investigate the thermal performance, under real conditions, of an innovative geopolymer-based insulated wall. It incorporates over 70% of net weight of Construction and Demolition Waste materials. The wall is conceived within the European project called “Green INSTRUCT” aimed to realize modular prefabricated building elements, for retrofitting and new construction of buildings. Two wall prototypes are analysed, which differ for the type of lightweight aggregate of geopolymer matrix, 3% by weight: expanded polystyrene or extruded polystyrene. The study refers to almost one year of continuous monitoring within a full-scale test room located in southern Italy. The method developed consists of 5 different phases and it involves also a normative-insulated reference wall. The results show higher insulation level of the proposed wall package, with a reduction of the heat flux of about 66% and more stable indoor thermal conditions, compared to the reference wall. Also the inertial properties are satisfactory, showing an experimental decrement factor equal to 0.05 and a time-shift of decrement factor higher than 6 h. All told, the experimental results can provide valuable insights into the real impact of innovative technology on energy efficiency and indoor thermal comfort.

Estimating the compressive strength of lightweight foamed concrete using different machine learning-based symbolic regression techniques

The development of concrete with excellent water and frost resistance providing high level of sound and thermal insulation has triggered the formulation of foamed concrete. However, multiple laboratory studies are required to produce reasonable data to design the relevant codes and mathematics with which design of mixes is made easier at low cost. In this research paper, the artificial intelligence (AI)-based symbolic regression technique estimation of the compressive strength of foamed concrete has been reported. Foamed concrete has been a subject of serious research in sustainable built-environment due to its lightweight and structural functionality. In this research work, data gathering method was applied to gather a globally representative data base comprising concrete density to water density (concrete density g/cm3) (γ/γw), water-cement ratio (W/C), and sand-cement ratio (S/C) as input variable and the compressive strength (Fc) as the study output. The dimensionless factors have been derived to eliminate data handling complexities and improve model performances. The 230 data entries from foamed concrete mixes were partitioned into 75% and 25% for training and validation data, respectively. At the end of the model execution, it was found that the response surface methodology (RSM) produced a symbolic closed-form equation like the genetic programming (GP), evolutionary polynomial regression (EPR), and the group method of data-handling-neural network (GMDH-NN). Even though the RSM closed with a minimum error, the GP, EPR and GMDH-NN were faster in runtime. The overall outcomes show that the GP outclassed the EPR, RSM and the GMDH-NN, though with minor margin. Meanwhile the EPR produced the highest outliers from the ±25% test of accuracy envelope. Overall, the present models outperformed those reported in the literature due the parameter reduction through dimensionless factors derivation and provided a decisive model to predict the Fc of foamed concrete.

Stability of intravenous medicines – evidence of maximum temperature reached in both summer and winter within soft shell elastomeric pumps

ObjectiveElastomeric devices or pumps are a valuable tool to deliver outpatient parenteral therapy and have been used for administration of chemotherapy, antibiotics and pain medication. A key determinant of effective...

State-of-the-Art Review: Effects of Using Cool Building Cladding Materials on Roofs

Cool roofs are roofing systems designed to reflect significant solar radiation, reducing heat absorption and subsequent cooling energy demands in buildings. This paper provides a comprehensive review of cool roof technologies, covering performance standards, material options, energy-saving potential, and hygrothermal considerations. The review examines provisions in current codes and standards, which specify minimum requirements for solar reflectance, thermal emittance, and solar reflectance index (SRI) values. These criteria often vary based on factors like roof slope, climate zone, and building type. Different cool roof materials are explored, including reflective paints and coatings that can be applied to existing roofs as cost-effective solutions. Several studies have demonstrated the energy performance benefits of cool roofs, showing significant reductions in cooling loads, indoor air temperatures, peak cooling demand, and overall cooling energy consumption compared to traditional roofs. However, hygrothermal performance must be evaluated, especially in cold climates, to optimize insulation levels and avoid moisture accumulation risks, as reduced heat absorption can alter moisture migration patterns within the building envelope. While cool roofs provide substantial energy savings in hot climates, further research is needed to validate modeling approaches against real-world studies, investigate the impact of seasonality and green spaces on cool roof efficacy and urban heat island mitigation, and explore energy-saving potential, moisture control, and condensation risks in cold and humid environments.

Assessing and comparing the environmental impact of smart residential buildings: A life cycle approach with uncertainty analysis

While there is an increasing integration of connected devices in buildings to reduce energy consumption, little evidence exists regarding the effective environmental impact of the smart devices installed. One goal of this study is to comparatively assess the impact of integrating connected devices on the environmental performances of existing buildings. Additionally, it aims to discuss the added value regarding environmental performance between a strategy of integrating connected devices and a refurbishment strategy. A non-refurbished connected building will thus be compared with a non-connected refurbished building. The approach's novelty lies in carrying out an uncertainty analysis, which addresses uncertainties in the environmental modelling of sensors, heating gains, and other influential building parameters, such as occupancy scenarios and building lifespan. The Life Cycle Assessment model is built on the results of a dynamic building energy simulation and integrates environmental data on connected devices from ecoinvent. Environmental indicators are calculated using ImpactWorld+. The methodology is applied to a multi-storey residential tower in France, characterised by a low insulation level. The alternatives compared include the original building without sensors, two connected alternatives (monitoring and management) that lead to a reduction of heating loads by 10 and 30% respectively, and a refurbished alternative. Results confidently show that using connected devices is always better than keeping the original building state. Yet, refurbishing the building is the preferable option across almost all indicators. Finally, the results point out that energy gains allowed by connected devices should be better quantified in further work through measurement campaigns.

Corrosion phenomena and deposits in ITER Neutral Beam Test Facility primary cooling circuits

The ITER Neutral Beam Test Facility (NBTF) is hosted in Padua and includes two experiments: MITICA, the 1 MeV full-scale prototype of the ITER HNB injector, and SPIDER, the 100 keV full-size ITER Radio Frequency (RF) negative ion source. SPIDER and MITICA experiments are actively cooled by Ultrapure Water (UPW) to electrically insulate in-vessel components that are biased to high voltage levels. Water conductivity is an important monitored parameter to ensure components' insulation by limiting the leakage current of active cooled equipment. A very low conductivity water is especially important in MITICA, where components need to operate up to 1 MVdc, an insulation level beyond the actual industrial standard. Careful selection of suitable materials for any in-vessel (vacuum insulation) and out-vessel component (air insulation) is of utmost importance, as their interaction with water and different environment may affect their chemical and mechanical properties. Additionally, materials selection can severely influence water chemical characteristics: cooling circuits are made of metals (copper, aluminium, steel) and insulating materials (plastic, rubber) when connecting parts at different electric potentials.During the first years of cooling plant exploitation, it was shown that water degrades more quickly than estimated by design. The Primary Circuits (PCs) that showed the most severe water degradation during operation are SPIDER and MITICA power supply ones, respectively called PC01 and PC08. This paper describes the results of specific experimental tests performed on MITICA PC08 to evaluate possible causes of water degradation and detect sources of contaminants that might compromise future experimental campaigns. The cooling circuit was subdivided in different sections and water circulation tests were performed at constant temperature and flowrate. Water samples were collected and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analyses were performed to quantify the type and amount of metals released. Moreover, components samples collected along their cooling circuits were characterized by Scanning Electron Microscope (SEM) technique to detect undesired contaminants and immersed in UPW to study their corrosion behaviour using metal release tests.

Impact of residential heat pumps and photovoltaics on low-voltage grid reinforcements under varying insulation levels

The European Union’s 2050 climate-neutrality goal necessitates extensive deployment of low-carbon technologies (LCTs) like heat pumps and rooftop photovoltaic systems in dwellings. However, integrating these into low-voltage (LV) grids can cause grid issues (e.g., voltage deviation, feeder overloading), often requiring grid reinforcements. This study uses a techno-economic approach to calculate the grid reinforcement costs under various residential LCT integration and insulation scenarios in representative rural and urban grids in Germany and Italy. Two cost calculation methods (maximum and average) are compared. Results indicate that, compared to the average cost calculation method, the maximum cost calculation method generally gives a higher cost under the same LCTs integration rate. Increasing LCT integration raises costs while improving residential dwelling insulation reduces them. The estimated reinforcement cost for rural and urban zones in Germany and Italy is significant and can be up to more than a billion euros. Improving residential insulation levels can reduce costs significantly for both German and Italian grids. The results and methodology presented can help grid operators and policymakers deploy LCTs in LV grids resiliently and cost-effectively.

The Impact of the Location of a Passive Frame House on Its Energy Demand for the Purpose of Heating—A Case Study

The reduction of energy demand in buildings is one of the key challenges in contemporary construction. To this end, the application of structural and material partitioning solutions that provide a high level of thermal insulation and the employment of technical installations with high energy performance have become widespread. However, there are a number of other factors that can reduce energy demand. These include the optimal use of heat gains from solar radiation. An aspect that is often discussed in the literature is the overheating of buildings due to excessive heat gains from solar radiation. This article is a case study showing the impact of the orientation of a single-family passive house on its heating energy demand. The building under consideration is located in Central Europe. External climate parameters measured directly at the site during experimental examinations were used for the calculations. This paper adopts six calculation options, considering the different orientations of the glazed façade. As the simulations showed, the effect of solar radiation on the energy demand between two extreme options of glazing orientation, that is south and north-facing orientation, reached 4.7% of the annual energy demand for heating, while for the option corresponding to the actual location of the building and the option involving south-facing windows, the difference was 0.3%, respectively.

Stress Strain Behaviour of Solid Block Masonry Prism under Axial Compression

Masonry is possibly the primary construction element currently in widespread use throughout the world. Load-bearing masonry building is prevalent in developing countries for home construction. When properly constructed, masonry is frequently a more cost-effective and energy-efficient alternative to reinforced concrete for wall building. In addition to performing the dual roles of supporting weight and enclosing space, structural masonry boasts a high level of fire resistance, thermal and acoustic insulation, and exposure protection. The remarkable durability and low maintenance costs are further evident benefits. Masonry has a significant role in building construction, particularly in structures, as it is regarded as the primary component of the building. The eco-friendly solid block is prepared by adding the following by-products like coal ash, granite powder, olivine sand etc., all these ingredients used for manufacturing the solid block are waste materials from various industries. Thus, extensive testing is necessary to assess their load carrying capacity and secant modulus accurately. Masonry prisms were developed with five-layer solid blocks and tested for their stress-strain characteristics and secant modulus and the test outcomes were compared with conventional fly ash cement blocks. Eco-friendly solid blocks offer a persuasive substitute for ecologically conscious approaches to building by preserving structural integrity and functionality while promoting sustainability.

Upcycling of industrial footwear waste into nonwoven fibrous structures with thermal and acoustic insulation properties

The footwear industry significantly impacts the environment, from raw material extraction to waste disposal. Transforming waste into new products is a viable option to mitigate the environmental consequences, reducing the reliance on virgin raw materials. This work aims to develop thermal and acoustic insulation materials using polyester waste from footwear industry. Two nonwoven and two compressed nonwoven structures, comprising 80% polyester waste and 20% commercial recycled polyester (matrix), were produced. The materials were created through needle-punching and compression molding techniques. The study included the production of sandwich and monolayer nonwoven structures, which were evaluated considering area weight, thickness, air permeability, mechanical properties, morphology using field emission scanning electron microscopy, and thermal and acoustic properties. The nonwoven samples presented high tensile strength (893 kPa and 629 kPa) and the highest strain (79.7% and 73.3%) and compressed nonwoven structures showed higher tensile strength (2700 kPa and 1291 kPa) but reduced strain (25.8% and 40.8%). Nonwoven samples showed thermal conductivity of 0.041 W/K.m and 0.037 W/K.m. Compressed nonwoven samples had higher values at 0.060 W/K.m and 0.070 W/K.m. While the sample with the highest conductivity exceeds typical insulation levels, other samples are suitable for thermal insulation. Nonwoven structures exhibited good absorption coefficients (0.640–0.644), suitable for acoustic insulation. Compressed nonwoven structures had lower values (0.291–0.536), unsuitable for this purpose. In summary, this study underscores the potential of 100% recycled polyester structures derived from footwear and textile industry waste, showcasing remarkable acoustic and thermal insulation properties ideal for the construction sector.

Compact Valve Hall Layout of DC Transformer for Offshore Wind Farm All-DC Collection Platform

Abstract To solve the problems of high investment cost, difficulty in improving AC collection efficiency, and broadband resonance in flexible DC transmission of offshore wind power, researchers have proposed an all-DC collection system. To further optimize the economic efficiency of offshore wind farm engineering, this paper studies on the compact valve hall layout of DC transformer for offshore wind farm all-DC collection platforms. The minimum air clearance inside the valve hall was determined based on the insulation level of the DC transformer, and a compact valve hall layout plan for the DC transformer was proposed, taking into account factors such as the electrical main wiring scheme, weight distribution, and symmetrical balance. The proposed compact valve hall layout scheme for DC transformers can reduce the volume of offshore all-DC collection platforms, save engineering construction costs, and improve the efficiency of offshore wind farms. This article can provide reference and guidance for subsequent research on all-DC collection and economic transmission of large-scale offshore wind farms.

Exploring insulation levels to enable low-temperature heating in selected buildings in two European climate zones

This study assesses the readiness of selected building types for low-temperature heating. This is accomplished by comprehensively analyzing buildings from two perspectives: first, by determining the level of insulation required for buildings to connect to 4th Generation District Heating, and second, by identifying techno-economically viable solutions to achieve these insulation levels.The authors used OpenStudio to thoroughly examine buildings’ thermal response when the heating supply temperature is reduced from 80 to 45 °C without changing radiators. Under these conditions, the aim was to determine whether the living areas inside the buildings could be maintained at 20 °C throughout the year. Starting from a baseline with no additional insulation and old windows, the study increases the intensity of the renovation packages to assess the minimum requirements needed to maintain the desired 20 °C in the heated areas. An economic feasibility study of the solutions proposed was also conducted. A sensitivity analysis was also performed, adding insight into the impact of energy prices on renovation measures.Eight buildings, encompassing a mix of actual structures and representative archetypes derived from the TABULA project, were examined across two different European climate zones. This study found that unrenovated buildings are particularly unready for low-temperature heating and will struggle to maintain 20 °C, especially during winter. Hence, this study delivers recommendations regarding insulation and heat demand reduction measures necessary to maintain appropriate comfort.The conclusions emphasize the necessity of renovating the building stock based on geographical location to guarantee appropriate indoor comfort when reducing the supply temperature for high-temperature radiators.

The impact of compromised insulation on building energy performance

Improving the performance of buildings is a key part of the global effort to limit greenhouse gas emissions and reduce energy consumption. Reducing the designed thermal transmittance of building envelopes through the addition of insulation is one of the primary measures adopted in many nations aiming to address the building sector. In theory, these globally adopted measures to improve design should result in considerable energy savings. The reality however is different. And a mismatch between design and in-use performance has been widely cited. This performance gap is extensively attributed to changes in occupant behaviour – the rebound effect. Considerably less research has investigated technical performance gap rationale. This paper aims to address this literature gap by investigating two technical reasons why design and in-use performance might differ; namely: i) moisture presence in the building’s insulation and ii) thermal bypass of the insulation system. The study uses a combination of thermal resistance analogies and computational fluid dynamics, to ascertain the extent to which compromised insulation would impact the performance of building envelopes. An increase in envelope heat loss results in an increase in a building’s energy consumption, and hence its associated greenhouse gas emissions. The study concluded that, in extreme cases, the presence of moisture in the insulation layers can increase the thermal transmittance of highly insulated envelopes by a factor of 2.2, while closed- and open-loop thermal bypass can increase it by a factor of 3.5 and 3.7 respectively. Although these might be considered extreme cases, the results align with findings from several past studies that quantified the gap between in-situ and design thermal transmittance. The results suggest that, while ensuring building envelopes are designed with adequate levels of insulation is important, ensuring that the insulation is adequately installed is potentially of equal importance.

A methodology to evaluate the optimal insulation thickness for heating and cooling needs in different climatic zones for buildings made of reinforced concrete with cavity walls

The study aims to define a methodology to evaluate the optimal insulation thickness with reference to the annual energy balance, including both heating and cooling seasons, for different climatic zones, based on three real case studies. The reduction of the heating needs due to the insulation of walls in places with cold climates is a consolidated concept. However, the effects of a high level of insulation of the envelope on the cooling needs has not yet been deeply analysed.The heating and cooling needs have been computed according to UNI/TS 11300 Italian standard by means of a commercial numerical model, varying the sizes of the buildings, the climatic zone, and the level of insulation. All the simulations concern buildings made of reinforced concrete frames with cavity walls, because of their wide diffusion as typical building technology of post war constructions.The work highlights the negative impact of the coating on the cooling needs, especially in the climatic zones with lower degree days. In almost all the climatic zones, the cooling need decreases its peaks during the hottest months (e.g., July or August), while the monthly load increases in the mild months (e.g., May, September) due to the additional thermal load which is no longer dispersed by means of the envelope. In conclusion, a range of optimal thicknesses for insulation for the different Italian climatic zones has been identified based on the total energy need of the building (cooling and heating).

Operation optimization and performance evaluation of a ventilated heating floor in a nearly-zero-energy building with mixed power

With the proportion of renewable energy in the construction sector increasing and the structure of energy systems becoming increasingly complex, it is crucial to optimize the operation strategy of building energy systems with thermal energy storage for improving multi-performance. However, conventional heuristic optimization algorithm exhibits low searching speed and converges slowly, which is hard for operation optimization of such systems. In this study, with a binary particle swarm optimization (BPSO) algorithm coupled with experience-based searching guiding strategy, the operation of a ventilated floor heating system in a nearly-zero-energy building was optimized . System performance under different optimization objectives and combinations, including reducing operation cost and carbon emission fee, meanwhile increasing wind power consumption and thermal comfort time, was investigated. Results show that with the experience-based accelerating strategy, the BPSO algorithm converged fast and found more reasonable solutions. In contrast, multi-objective optimization yielded better and diverse feasible solutions were found than single-objective optimization. By optimizing operating costs, wind power consumption, and environmental costs, the best comprehensive solution was obtained. The cost range of energy consumption and carbon emissions within 10 days is 19.24–22.17 yuan and 17.45–20.11 yuan, respectively. The proportion of thermal comfort time is 95.39–95.82%. However, due to high thermal insulation level, thermal comfort time under different optimization objectives showed little difference.

Evaluating the impact of peat soils and snow schemes on simulated active layer thickness at pan-Arctic permafrost sites

Abstract Permafrost stability is significantly influenced by the thermal buffering effects of snow and active-layer peat soils. In the warm season, peat soils act as a barrier to downward heat transfer mainly due to their low thermal conductivity. In the cold season, the snowpack serves as a thermal insulator, retarding the release of heat from the soil to the atmosphere. Currently, many global land models overestimate permafrost soil temperature and active layer thickness (ALT), partially due to inaccurate representations of soil organic matter (SOM) density profiles and snow thermal insulation. In this study, we evaluated the impacts of SOM and snow schemes on ALT simulations at pan-Arctic permafrost sites using the Energy Exascale Earth System Model (E3SM) land model (ELM). We conducted simulations at the Circumpolar Active Layer Monitoring (CALM) sites across the pan-Arctic domain. We improved ELM-simulated site-level ALT using a knowledge-based hierarchical optimization procedure and examined the effects of precipitation-phase partitioning methods (PPMs), snow compaction schemes, and snow thermal conductivity schemes on simulated snow depth, soil temperature, ALT, and CO2 fluxes. Results showed that the optimized ELM significantly improved agreement with observed ALT (e.g. RMSE decreased from 0.83 m to 0.15 m). Our sensitivity analysis revealed that snow-related schemes significantly impact simulated snow thermal insulation levels, soil temperature, and ALT. For example, one of the commonly used snow thermal conductivity schemes (quadratic Sturm or SturmQua) generally produced warmer soil temperatures and larger ALT compared to the other two tested schemes. The SturmQua scheme also amplified the model’s sensitivity to PPMs and predicted deeper ALTs than the other two snow schemes under both current and future climates. The study highlights the importance of accurately representing snow-related processes and peat soils in land models to enhance permafrost dynamics simulations.