Air Temperature Difference Research Articles

Alternative climatic steady states near the Permian-Triassic Boundary.

Due to spatial scarcity and uncertainties in sediment data, initial and boundary conditions in deep-time climate simulations are not well constrained. On the other hand, depending on these conditions, feedback mechanisms in the climate system compete and balance differently. This opens up the possibility to obtain multiple steady states in numerical experiments. Here, we use the MIT general circulation model to explore the existence of such alternative steady states around the Permian-Triassic Boundary (PTB). We construct the corresponding bifurcation diagram, taking into account processes on a timescale of thousands of years, in order to identify the stability range of the steady states and tipping points as the atmospheric CO2 content is varied. We find three alternative steady states with a difference in global mean surface air temperature of about 10°C. We also examine how these climatic steady states are modified when feedbacks operating on comparable or longer time scales are included, namely vegetation dynamics and air-sea carbon exchanges. Our findings on multistability provide a useful framework for explaining the climatic variations observed in the Early Triassic geological record, as well as some discrepancies between numerical simulations in the literature and geological data at PTB and its aftermath.

Numerical simulation of an innovative design of solar air heater using spiral duct inserts for enhancing thermal efficiency

ABSTRACT An innovative design of solar air heater (SAH) with spiral shape is numerically analyzed in this paper. The spiral-shaped SAH hydro-thermal performance is studied for different air mass flow rates using CFD COMSOL Multiphysics software. The outlet air temperature difference, thermal efficiency, flow structure, thermal field and pressure drop are the main parameters which are considered to estimate the fluid flow and heat transfer behaviors of the SAH. The simulation is realized for 1000 W/m2 of solar heat flux and 25°C of ambient temperature as typical climatic conditions in a middle day. The results show that the maximum outlet temperature difference of the SAH reached 93.08°C with 0.0083 kg/s of air mass flow rate. For the range of 0.0083–0.0332 kg/s, the thermal efficiency is varied from 91.41% to 99.01%. The ambitious percentage of the thermal efficiency of 99.01% was observed for 0.012 kg/s. The proposed design provides high thermal efficiency of SAH compared to other configurations of SAH.

A comparative performance study of terminal control strategy for the multi-split backplane cooling system in data centers

Multi-split backplane cooling, a typical rack-level cooling technology, has the advantage of solving local hot-spot problems with huge energy-saving potential. These systems adopt the multi-split mode, and the operation effect is affected by terminal control performance. However, there are factors in the operation process, such as superheat degree (SH), rack airflow, evaporating/condensing pressures, etc., which improve the control complication, particularly under large head load differences among different terminals. Therefore, appreciative control strategies for outlet air temperatures of terminal evaporators, including single-loop control limited by minimum stable superheat degree (SLC) and fan/electronic expansion valve (EEV) double-loop control (DLC), are proposed considering that cooling performance can be affected by both refrigerant flow and airflow. Then, comparative simulation studies are carried out to evaluate energy efficiency, control effect, and feasibility under the condition of different server heat distribution characteristics. Results indicate that the DLC strategy achieves 23% higher energy efficiency than the SLC strategy with a better temperature control effect when the inlet air temperature (IAT) difference between terminal evaporators is within ±5K. The SLC strategy has better reliability by more stable control of SH at IATs below 42°C, but it may lead to cooling failure when IATs exceed 42°C. An insufficient liquid supply problem may happen to the evaporator adopting the DLC strategy when the IAT is too high, which can be solved by adjusting the pressure differential between the evaporator and condenser. Moreover, the DLC system exhibits intense coupling effects, and how to decouple it is worthy of further study.

Thermal performance of thermochromic smart windows in different indoor environments

Thermochromic (TC) smart windows can passively respond to the exterior and interior temperature, which further adjust their indoor thermal environments due to the varied photo-thermal parameters. This study investigated the thermal performances of practical TC windows in a room with/without air-conditioning or with stratified temperature distribution through a validated 3D CFD model. The application of TC windows could decrease the window, indoor ambient and floor temperatures, and also improve their temperature uniformity. The upper interior window could be 3.13 °C higher than the bottom in a room without air-conditioning, which could be reduced to 2.48 °C if the TC window was utilized. The uniformity improvement could be more significant for indoor environments with apparent air temperature differences, especially for the air-conditioning case. It is suggested that the indoor air temperature and its uniformity may affect the temperature and uniformity of the TC window surface in turn, specifically its phase transition time.

Research on a novel method of air distribution to create a uniform indoor environment in a long and narrow building

Because people work a long time in buildings, good indoor thermal environments and air distributions have attracted increased amounts of attention. To improve the indoor thermal environment and air quality, an effective ventilation strategy must be used. In the air conditioning of a building, the air distribution has been identified as a significant factor that affects the indoor thermal environment. A novel method for air distribution was presented to create a uniform indoor environment along the room length direction. In this study, numerical simulations were carried out to analyse the airflow pattern and performance of the sidewall air supply (SAS) and the sidewall air supply with deflector (SASD). Orthogonal experiments were conducted to study the airflow distribution law of the deflector. The ventilation performance of the two air supply modes was evaluated by air velocity distribution, temperature distribution, horizontal temperature difference, age of air, and other evaluation indicators. The results indicate that the horizontal air temperature differences in the SASD at three heights are 46.05%, 16.44%, and 26.51% lower than those in the SAS, which has a better energy-saving effect. Moreover, the indoor air distribution performance was obtained under three influencing factors: the gap width from the deflector to the ceiling, the horizontal position, and the length of the deflector. A better deflector optimization scheme was obtained. Experimental research was carried out to verify the indoor air distribution of the SASD. This research can provide a reference for the innovative design of indoor air supply systems

Predictive heating load management and energy flexibility analysis in residential sector using an archetype gray-box modeling approach: Application to an experimental house in Québec

This paper presents a methodology to develop archetype gray-box models and use them in an economic model-based predictive control algorithm to simulate optimal heating load management in response to a newly-introduced static time-of-use tariff for Québec’s residential sector, rate Flex-D. The methodology is evaluated through a case study, wherein in situ measurements from a two-storey unoccupied research house of Hydro-Québec are used to develop an 11R6C network with a heuristic zoning-by-floor approach and compute the sequence of optimal electric heating input for the next control horizon. Properly-tuned economic model-based predictive control under rate Flex-D shows potential for an approximately 30% reduction in daily heating cost compared to the reference operation, with a minimal average deviation of indoor air temperature from the reference setpoint. Also, the analysis of the response’s sensitivity to weather forecast uncertainties indicates that the most influential uncontrolled input directing the performance of economic model-based predictive control is the structure price signal, rendering the impact of uncertainty in the weather forecast negligible.

Microclimate Effect on Cooling Energy for Buildings in Hot, Humid Climates: A Comparative Analysis of Shaded and Unshaded Environments

This paper explores the influence of microclimates on changes in air temperature and the often-overlooked aspect of their effect on energy savings across varying microclimatic conditions. The study compares the cooling energy requirements of two identical single-story buildings in distinct microclimates: one characterized by concrete ground devoid of shade and the other featuring soil ground with tree shade. Climatic environmental data were collected over 15 days in the concrete-exposed field and shaded area beneath the trees to conduct the investigation. These datasets were input into EnergyPlus 9.6 to model the energy demands and consumption of buildings subject to the specified climatic conditions. The validation of the simulated model against actual energy demand data from a classroom building demonstrated agreement. The findings reveal notable differences in air temperature, with the shaded area experiencing temperatures 0.8°C to 8.0°C lower than the concrete-exposed monitoring location. The building in the tree-shaded microclimate exhibited a lower peak cooling load than its concrete-exposed counterpart, resulting in a 35% reduction in the electrical energy requirements for the air-conditioning system. The study recommends implementing 0.08-m polyurethane insulation for the building walls and roof to equalize the energy demand and consumption of the concrete-exposed building with that of its shaded counterpart. Furthermore, building design in shaded areas can maximize the window glass area while consuming less energy than buildings on concrete-exposed grounds. The study advocates leveraging the microclimate associated with surrounding buildings in the design process to enhance the overall energy savings.

Surface energy fluxes in a drip-irrigated agroecosystem: Unique advection effect of oasis

Surface energy fluxes, mainly encompassing the net radiation (Rn), latent heat flux (LE), sensible heat flux (Hs), and soil heat flux (Gs), play an important role in the land-atmosphere interactions. However, almost all sites face the problem of energy imbalance, and advection fluxes associated with large inhomogeneous surfaces have been ignored, especially in arid oasis areas. In this study, a three-year continuous measurement of energy fluxes with an eddy covariance system was conducted in a drip-irrigated oasis agroecosystem in Northwest China. Reanalysis data including air temperature (Ta), soil moisture (θ), and leaf area index (LAI) in our cropland and surrounding deserts were also collected. The results showed that multi-year mean turbulent fluxes (LE+Hs) accounted for 75 ± 8 % (mean ± standard deviation) of available energy (Rn–Gs). To be precise, LE took up 72 ± 10 % of available energy, and 7.8 ± 2.8 % of it was induced by higher sensible heat advection, proving a pronounced advection effect in this study. When advection was present, most likely during the heading stage, the threshold value for the Priestley–Taylor parameter α, an indicator to reflect the advection effect, fell in the range of 0.88–1.34. Additionally, after a significant irrigation event, α showed a good linear relationship with differences in air temperature (ΔTa), soil moisture (Δθ), and leaf area index (ΔLAI) between our cropland and surrounding deserts. It's worth mentioning that Δθ was the most significant factor, showing a negative correlation with the advection effect. This study has deepened our understanding of the energy balance in oasis agriculture, emphasizing that the advection effect should not be overlooked.

Thermal environmental and energy effects of vertical greening system under the influence of localized urban climates

Vertical greening system (VGS) can cool adjacent urban space and lower building conditioning energy use without consuming valuable land area, however the influence of local microclimate on the effects is understudied. To better understand how VGS behaves environmentally in localized urban climates, the study investigated the outdoor cooling and building energy-saving potential of a VGS in five local climate zones (LCZ) in Shanghai, using integrated modeling with ENVI-met and EnergyPlus. The model verification reasonably reflects the relative differences in thermal effects of VGS due to local climates. The result reveals that, under the maximum inter-LCZ differences in air temperature (Ta) and relative humidity (RH) of 1.4 °C and 5.3 %, the greatest inter-LCZ variations in cooling and humidifying effects of the VGS are 0.16 °C and 1.1 %, respectively. The VGS creates greater adjacent Ta reduction in higher-ranked LCZs, by up to 0.27 °C, but increases RH by 1.6 %. In summer, the VGS provides energy savings of 132–278 Wh/m2 with energy saving rates of 5.7–11.7 %. The annual energy savings are partially offset by the increase in winter heating, and the annual energy saving rates are reduced to 3.2–6.3 %. Of the savings, 92 % is due to shading, 8 % to cooling, and the humidifying effect has a negative impact (- 11 %). The findings underscore the impact of localized urban climates on the VGS thermal and energy performances, and support climate-responsive and performance-optimized urban VGS planning and application.

Analysis of thermal insulation effect of off-wall insulation lining in high-temperature tunnel

Most prior studies on the insulation effect of off-wall insulation have neglected the natural convection of the air lining; this assumption is inconsistent with reality. In this study, the effect of natural air convection on the heat transfer mechanism in off-wall insulation lining was studied via experiments and numerical simulation. The thermal insulation effect of the air lining was evident. The temperature field distribution of the surrounding rock is affected by the natural convection in the air lining and is thus clearly related to the azimuth. The temperature disturbance of the surrounding rock in the direction of θ = 0° is the minimum, whereas that in the direction of θ = 180° is the maximum. The most significant factors affecting the thermal insulation effect of the off-wall insulation lining are the thermal conductivity of the rock and thermal resistance of the insulation layer, followed by thickness of the air lining and temperature difference between the original rock temperature and the air flow. The relationships between the average unstable heat transfer coefficient and various parameters were obtained via fitting. The fitting formula can be used in engineering practice to calculate the heat transfer from the surrounding rock to the tunnel airflow under various conditions.

Elucidating the boundary layer turbulence dissipation rate using high-resolution measurements from a radar wind profiler network over the Tibetan Plateau

Abstract. The planetary boundary layer (PBL) over the Tibetan Plateau (TP) exerts a significant influence on regional and global climate, while its vertical structures of turbulence and evolution features remain poorly understood, largely due to the scarcity of observations. This study examines the vertical profile of and daytime variation in the turbulence dissipation rate (ε) in the PBL and free troposphere over the TP using the high-resolution (6 min and 120 m) measurements from a radar wind profiler (RWP) network, combined with hourly data from ERA5 during the period from 1 September 2022 to 31 October 2023. Observational analyses show that the magnitude of ε below 3 km under all-sky conditions exhibits a large spatial discrepancy over the six RWP stations over the TP. Particularly, the values of ε at Minfeng and Jiuquan over the northern TP and at Dingri (alternately Tingri) over the southern TP are roughly an order of magnitude greater than those at Lijiang, Ganzi (alternately Garzê), and Hongyuan over the eastern TP. This could be partially attributed to the difference in land cover across the six RWP stations. In terms of the diurnal variation, ε rapidly intensifies from 09:00 local standard time (LST) to 14:00 LST and then gradually levels off in the late afternoon. Under clear-sky conditions, both ε and the planetary boundary layer height (zi) are greater compared with cloudy-sky conditions, which could be due to the cooling effect of clouds, which reduces the solar irradiation reaching the surface. In the lower PBL (0.3 ≤ z/zi ≤ 0.5), where z is the height above ground level, the dominant influential factor in the development of turbulence is the surface–air temperature difference (Ts−Ta). By comparison, in the upper PBL (0.6 ≤ z/zi ≤ 1.0), both Ts−Ta and vertical wind shear (VWS) affect the development of turbulence. Above the PBL (1.0 < z/zi ≤ 2.0), the shear production resulting from VWS dominates the variation in turbulence. Under cloudy-sky conditions, the reduced Ts−Ta and weakened surface sensible heat flux tend to inhibit the turbulent motion in the PBL. On the other hand, the strong VWS induced by clouds enhances the turbulence above the PBL. The findings obtained here underscore the importance of the RWP network in revealing the fine-scale structures of the PBL over the TP and gaining new insight into the PBL evolution.

Experimental evaluation of localized air temperature profile and performance of serpentine copper tube heat exchanger for energy-saving crop cultivation

The objective of this study is to examine the localized air temperature profile and heat transfer performance of a serpentine copper tube heat exchanger. Particularly, the air temperature nearby the plants is controlled by the heat exchanger. The novelty of this study is to provide localized climate control only near the plants targeting periodic air temperature control with the proposed heat exchanger. This study focuses on heating and cooling for cultivation in temperate and tropical regions. In contrast to fin-and-tube heat exchangers, the serpentine heat exchanger has a simple design, provides minimal shade for plants, and is easy to maintain. This study was conducted in a laboratory. The experimental system was constructed under with the assumption that a part of actual plant cultivation was being left out. The experiments were implemented by varying the experimental operating conditions such as the inlet fluid temperature and fluid flow rate in the heat exchanger. The pressure drop in the heat exchanger was also measured. The results revealed that this heat exchanger could provide localized air temperature control. The maximum air temperature difference can be obtained at approximately 12 °C during cooling and heating from their initial air temperature even though the heat exchange is simple. The effects of decreasing the inlet fluid temperature for cooling and increasing the inlet fluid temperature for heating were more dominant than the effect of the flow rate. This simple, low-maintenance, and low-cost serpentine copper tube heat exchanger can effectively provide alternate heating and cooling for plant cultivation.

Comparison of the environmental, energy, and thermal comfort performance of air and radiant cooling systems in a zero-energy office building in Singapore

In an experimental study set in Singapore’s tropical climate, we evaluated the thermal environmental performance, energy consumption, and thermal comfort of air and radiant cooling systems, operating at an operative and air temperature of 26 °C. 78 participants across five groups answered thermal comfort surveys in a crossover study design. Environmental performance metrics indicated that both systems produced similar conditions, with a noticeable difference in air velocity. The mean radiant temperature to air temperature difference was less than 0.5 °C in both systems. The radiant system exhibited a 33 % higher heat flux extraction than the air system and required less electrical power for the transportation of the cooling medium and ventilation air. Overall, the radiant system used 4 % less energy than the air system when controlled at 26 °C and 34 % when operated at 23 °C. Results show that radiant and air systems provided equal thermal comfort in cooling, with over 60 % of participants expressing satisfaction and ∼ 20 % voted neutral thermal satisfaction. ∼ 40 % of participants preferred cooler conditions, and ∼ 30 % desired increased air movement.

The Influence of Land Cover on Spatio-Temporal Variation of Air Temperature in Grogol District, Central Java – Indonesia

As an urban fringe of Surakarta City-Indonesia, Grogol District is experienced by increasing temperature. The purpose of this study is: 1) to determine the spatial and temporal variations of air temperature in the Grogol District and 2) to determine the difference in air temperature between built-up land cover and non-built-up land cover, particularly rice fields. Air temperature data was obtained by temperature data logger from four sample points on October 27th to December 13th, 2021. Air temperature and land cover data were analyzed by descriptive and inferential statistics as well as spatial interpolation on air temperature data. The result indicates that higher air temperatures are spread over the northern part which is dominated by settlements. Lower air temperatures are found in the southern part which is dominated by rice fields. The temporal variation of air temperature at the four sample points shows almost the same pattern. However, the air temperature was higher in the built-up land cover than in the rice fields. The statistical difference test also showed that there were differences between the two land covers. In conclusion, Grogol District is affected by the urban heat island phenomenon from Surakarta City. This is particularly related to land cover change and increasing population. Therefore, to prevent the increasing temperature, the protection of the open greenspace area should be implemented.

Investigation of the effect of dimensional and non-dimensional parameters on the performance of pitch-varied staggered arranged dimple solar air heaters

In this study, the efficacy of a single pass, single glazed, five different types of absorber plate incorporated solar air heater (SAH) was experimentally examined in outdoor test conditions on alternative days. The experiment was carried out for flat plate solar air heater (FPSAH) and staggered arranged dimple imprinted absorber plate solar air heater (SDPSAH) maintained at four different pitch ratios (Pt/Pl: 1.0, 1.11, 1.25, and 1.67) by varying the air mass flow rate (ma) from 0.01-0.05 kg/s (corresponding Re range: 1971.66–10466.45). The results show that the performance of both FPSAH and SDPSAH improves when the ma increases. For the tested range of ma, SDPSAH outperforms FPSAH regardless of pitch ratio. SDPSAH, with a pitch ratio of 1.25, on the other hand, has a greater air temperature difference, efficiencies, heat removal factor, collector efficiencies, and averaged Nusselt number (Nuavg) while having a lower global heat loss coefficient and top loss. The Nuavg of SDPSAH at a pitch ratio of 1.25 is 1.01–1.17, 1.16–1.24, 1.26–1.57, and 1.44–1.88 times higher than SDPSAH at pitch ratios 1.0, 1.11, 1.67, and FPSAH, respectively. The higher averaged friction factor (favg) of 0.0443 is attained for SDPSAH at a pitch ratio of 1.25 due to the presence of the largest number of dimples. The ηth and ηd of SDPSAH at a pitch ratio of 1.25 are 34.5 and 35.5 % higher than those of FPSAH. The global heat loss coefficient of SDPSAH at pitch ratios 1.11, 1.0, and 1.67 is 1.05–1.84, 1.09–2.15, and 1.11–2.92 times higher, respectively, than that of SDPSAH at a pitch ratio of 1.25.

Impact of a water restriction on the summer climatic benefits of trees inside an outdoor street canyon scale model

Trees may help reduce the increasing human thermal stress in cities caused by the Urban Heat Island phenomenon and the multiplication and intensification of heatwaves through the climatic benefits they provide: cast shadows and transpiration. However, the multiplication of droughts may lower the water supply of street trees and impact their development and climatic benefits. The transpiration and radiation interception of two alignments of potted ornamental apple trees (Malus Coccinella® ‘Courtarou’) planted in a 1/5 scale street canyon experiencing contrasted water supplies were monitored during an 8-week period of summer 2022. Compared to well-watered trees, the transpiration of water-restricted trees was reduced quickly and strongly by 81 % on average. A noticeable reduction of the leaf area index of the water-restricted trees led to a decrease of their radiation interception which however remained higher than 69 % of the incident radiation measured without trees. No noticeable air temperature difference was measured under the tree crowns of both alignments of trees but the Universal Thermal Climate Index calculated under the water-restricted trees increased by on average 1 °C. Radiation interception appeared to be responsible for the major part of the daily total amount of energy dissipated. A noticeable reduction of the daily total amount of energy dissipated by the WR trees was mostly attributed to the reduction of their transpiration which may explain why both alignments of trees kept providing noticeable climatic benefits.

Experimental investigation of the use of a radiant porous burner in a novel dual hot air generator based on the food drying process

AbstractHot air generators are essential for food drying processes, operating in either indirect or direct modes. In this study, a high‐power radiant porous burner in a novel dual hot air generator (HAG‐D) was designed and experimentally investigated. Temperatures and emissions of the combustion process are reported for 9, 13, and 18 kW, and 20% and 40% of excess air. Indirect and direct modes were tested across airflow rates of 300–1100 m3/h to assess thermal efficiency. For indirect mode operation, 88% thermal efficiency is the highest value for 9 kW, 20% excess air, with an airflow of 890 m3/h observing air temperature difference (outlet minus inlet) of approximately 30°C. Furthermore, CO and NOx emissions were found in the range of 0–30 ppm and 20–45 ppm, respectively. For direct mode operation, results showed that for 18 kW with 20% and 40% excess air, the maximum thermal efficiency was 82% with an airflow of 670–1040 m3/h and air temperature difference in the range of 50–80°C. Results confirm that the radiant heat transfer mechanism allows for higher efficiencies and less pollution in a wide range of powers in the HAG‐D unit. The direct mode is recommended for food drying processes due to low exposure to flue gases, and the indirect mode is for other industrial applications due to its high efficiency. Future studies are suggested to assess renewable fuels, such as liquefied petroleum gas or natural gas and hydrogen mixtures, toward energy transition.Practical applicationsThe potential applications or practical benefits of the develop of this novel dual hot air generator is in the food industry, particularly in drying process of fruits and vegetables. Also, air conditioning, and space heating (household use) processes stand out among their several applications to generate hot air, such as paint, and wood.

Traces of Local Adaptive Acclimatization Response in the Tracheid Anatomical Traits between Dry and Wet Mesic Norway Spruce (Picea abies) Forests in Moravia, Czech Republic?

Norway spruce (Picea abies) forests in temperate zones are already reacting to short-term extreme summer heatwaves, threatening the vitality of trees and forest productivity, and can even lead to local and regional dieback events. Examining quantitative wood anatomy can provide helpful information in terms of understanding the physiology mechanisms and related responses of conifer trees to local environmental interactions in relation to tracheid adaptive capacity. This study analysed the tracheid functional anatomical traits (FATs) plasticity of six young Norway spruce trees growing in two mesic research plots with high annual precipitation (~43%) and air temperature differences during 2010–2017. The research plots are located in the sub-mountainous (Rájec Němčice) and mountainous (Bílý Kříž) belts of the Moravia region, Czech Republic. Vapour pressure deficit and cell wall reinforcement index (CWRI) were shown to be the most representative environmental parameters as proxies of dry conditions. Tracheid FATs indicated latewood phenological plasticity sensitivity, with more pronounced variability in the warmer and drier plots. Latewood tracheids of Norway spruce trees grown in the RAJ formed significantly thicker cell walls than BK during the studied period. The observed differences between the two research plots indicate additional support for tracheid cells’ hydraulic safety against cavitation and potential traces of adaptive acclimatization response.

Research on a New Soundscape Evaluation Method Suitable for Scenic Areas

Existing studies have focused mainly on the environmental quality of scenic spots, such as sufficient oxygen content in the air and a high concentration of negative oxygen ions. The perceptions of soundscape in scenic areas are generally good, but there are few reports on the quantitative evaluation of soundscape quality in scenic areas. In this study, we analysed existing methods for evaluating the soundscape of a landscape, evaluated the soundscape comfort of scenic spots, analysed and refined the natural environmental factors affecting the soundscape, and proposed for the first time to use physical environmental indicators such as the air temperature difference, relative humidity, natural illuminance ratio and wind speed as environmental evaluation variables. A quantitative method was used to calculate the soundscape comfort index (SSI) of the landscape. The physical environmental indicators related to famous scenic spots in China, namely, Qingcheng mountain field testing and a subjective soundscape of tourist satisfaction survey, were used to calculate the corresponding soundscape comfort index values, and a quantitative analysis of soundscape comfort and differences in temperature, relative humidity, the illumination ratio, and the correlation between the equivalent sound level A was performed. The measured values of the temperature difference and light ratio were significantly correlated with the soundscape comfort index. The distribution of sound landscape comfort was given by a GIS map, and soundscape comfort was evaluated scientifically. The correlations between soundscape comfort and landscape patch number (PN), landscape patch density (PD), diversity index (Shannon), and landscape shape index (LSI) were quantitatively analysed, which confirmed that the perception of soundscape comfort was affected by landscape space to different degrees. This study has scientific significance and application value for the soundscape evaluation of scenic areas and has significance for soundscape evaluation and design strategies for urban landscapes.

Enhancing indoor thermal comfort and energy efficiency: A comparative study of RC-PCM Trombe wall performance

In response to the issue of excessive heating during summer in traditional Trombe walls, this study proposes a novel system called RC-PCM Trombe walls, which utilizes radiation cooling and phase change materials (PCMs) to traditional Trombe walls. The thermal performances of RC-PCM Trombe wall, conventional Trombe wall, and PCM Trombe wall were compared and studied under summer conditions. The experimental results demonstrate that the addition of heat pipes and radiant cooling devices to the RC-PCM Trombe wall led to a reduction of peak temperatures on the inner surface of the south wall by 3 °C and 1.2 °C, respectively. Furthermore, the time taken to reach the peak temperature was delayed by 43 min and 38 min, respectively. The standard deviations of indoor air temperature were reduced by 0.04 °C and 0.29 °C, while the indoor heat gain was reduced by 26.5 % and 55.2 %, respectively. These findings indicate that the RC-PCM Trombe wall effectively mitigates indoor overheating and enhances the indoor thermal environment during the summer.