Indoor Temperature Research Articles

Study on indoor temperature optimal control of air-conditioning based on Twin Delayed Deep Deterministic policy gradient algorithm

The optimization of HVAC system control affects the thermal comfort of building environment and air-conditioning energy consumption. However, most existing studies concentrate on human thermal comfort and neglects to incorporate air-conditioning energy consumption required to establish a controlled indoor thermal environment within the policy, which results in air-conditioning system high energy consumption. This paper suggests an indoor temperature intelligent control method based on thermal comfort and energy consumption of air-conditioning, and the TD3 algorithm is employed as an intelligent control algorithm to obtain the optimal setpoint that maximizes the joint benefit of the occupant’s thermal comfort and the energy saving rate of air-conditioning system. The air-conditioning indoor temperature intelligent control model based on TD3 algorithm is trained by using the experimental data, and the method is simulated in TRNSYS simulation software to corroborate the efficacy and energy saving rate of the method. The results indicate that the indoor temperature intelligent control model based on thermal comfort and energy consumption of air-conditioning has less optimal adjustment of indoor temperature setpoints, which is more stable for the air-conditioning system and can satisfy the thermal comfort demand at the initial control stage to prevent significant fluctuations in human thermal sensation compared to the linear control method based on thermal sensation and the fuzzy control method based on thermal sensation. Besides, the average daily energy consumption can be reduced by 6.54% and 3.37% respectively, when compared to the linear control method based on thermal sensation and the fuzzy control method based on thermal sensation.

Energy optimization for Façade retrofit design of residential buildings in hot climates using advanced materials

Global warming has adversely affected the building sector in many countries. Energy retrofit strategies for existing buildings have been developed to combat this issue, including advanced facade system coatings. This study examines how advanced coatings such as PCMs, thermochromics, and cool materials can be effectively used to enhance the thermal behavior and energy performance of existing facades in hot climates. It aims to suggest the optimal combinations of such materials for the façade retrofit design of a typical low-rise residential building in hot climates. Using optimization, Design Builder software is utilized to assess the thermal behavior and energy performance of a combination of advanced materials used. The results revealed that the arrangement of exterior wall layers, thickness and placement of thermal insulation, and the material used in the façade outer layer have a significant effect on the annual energy consumption. Applying coatings with high reflective values as an outer layer of facades can reduce monthly surface temperatures by 2.62 °C in summer and annual cooling loads by 13.78 %. Using PCM coating as an inner layer of the façade improves indoor temperatures by 1.83 °C during different seasons and decreases annual cooling demands by 13.23 %. Finally, the optimal combination of such materials for the energy retrofit design of a typical residential building with three conventional façades has been defined.

Field experiment examining condensation reduction methods based on underground parking lot types

ABSTRACT In this study, condensation reduction methods with high field applicability to various types of underground parking lots in apartment buildings were selected and tested. The selected methods included floor-insulating drainage plates, induction fans with heating wires, and an automatic control ventilation system based on indoor and outdoor temperatures and humidity. The effectiveness of these methods was evaluated via real-world field experiments. The results indicated that while the insulating drainage plates initially blocked the cold, their long-term effectiveness matched that of normal drainage plates (difference 0.1°C). The induction fan with a heating wire showed average increases of 0.8°C and 2.7°C in wall surface temperature after one and three months, compared to normal induction fans. The absolute humidity of the automatic control ventilation decreased by 1.8 g/kg after 10 h of operation during rainy weather, whereas the manual control ventilation system increased by 0.6 g/kg under the same conditions. This study offers insights into the most effective application of these methods for various parking lot configurations.

Subjective evaluation of thermal comfort of tropically acclimatized subjects in air conditioned, naturally ventilated and radiant cooling environments

The thermal sensation of people is subjective. It depends on the external climatic condition and thermal history of a person. Thermal comfort standards suggest a narrow temperature range to assert an environment as comfortable or otherwise. It is important to evaluate people’s thermal perception in different climatic regions and set comfort limits based on their thermal perception. This study evaluates the thermal perception of subjects in hot and humid climatic regions at higher indoor temperatures and air velocities. Three different thermal environments chosen for the study are air conditioned (AC), naturally ventilated (NV), and radiant cooling (RC) thermal environments. The study shows that more than 80% of subjects voted as comfortable in AC and RC thermal environments for the measured Top and va range of 25.3 – 28.4℃/0.1 – 0.3m/s and 25.9 – 29.1℃/0.1 – 0.9m/s respectively. The findings gathered from the study in NV environment indicate that 68% of subjects opt for the use of table fans over ceiling fans. The subjects' free control of air movement improves their thermal sensation over no control of air movement, indicating that they prefer table fans and free control of air movement. In AC, NV, and RC thermal environments, humidity and air quality remain uncontrolled. In AC and RC thermal environments, less than 20% of subjects voted unacceptable for the humidity sensation and Perceived air quality (PAQ) scales in nearly all the studied experimental conditions. In NV thermal environment, the percentage of subjects voting dissatisfied on the humidity sensation scale and PAQ scale is 30-52% and 26-37%, respectively. This outcome shows that a thermally comfortable environment with air movement improves subjects' humidity sensation and PAQ even when humidity and air quality are unaltered. The study points out that air velocity played a vital role in influencing the thermal sensation, humidity sensation and perceived air quality of subjects in the three studied thermal environments. Further the study shows that with free control of air movement will significantly aid in rising the comfort temperature band of tropically acclimatized subjects. Practical application The study shows the variation in limits of thermal comfort indices such as operative temperature and air velocity for tropically acclimatized subjects in three thermal environments. The same group of subjects participated in the subject study conducted in air conditioned, naturally ventilated and radiant cooling thermal environments. The outcomes indicate that subjects are comfortable at higher indoor temperature and air velocity. Further the outcomes showed that the humidity and air quality sensation of subjects is influenced by the subjects’ thermal sensation and air velocity.

Lime Hempcrete Composites Based on Unfired Binders. A Review

AbstractHempcrete has emerged as a viable and environmentally sound building material based on hemp lime mixture, whose properties render it a low Embodied Energy and Carbon (EE and EC) building material. Additionally, it allows a hempcrete building to achieve low Operational Energy and Carbon (OE and OC) by moderating indoor temperature and relative humidity fluctuations through the year with minimal auxiliary heating or cooling. Hemp shives used in hempcrete are a waste product, yet lime is an energy intensive material. This paper summarizes a research project the purpose of which was to investigate the possibility of substituting the lime in hempcrete with unfired binders, in part of whole, thus lowering the EE and EC of the mixture even further. Results of this research have shown that this is possible without compromising any of the traditional hempcrete properties, e.g., compressive strength and insulating value. A comprehensive Life Cycle Energy Analysis (LCEA) and Life Cycle Carbon Analysis (LCCA) has shown total energy requirements for a prototypical building’s lifespan (50 years) to be between ~ 50–10% of an identical building with conventional materials, and total carbon emissions to be respectively ~ 50–10%.

Thermal storage cementitious materials containing SiO2-coated cenosphere@bio-based PCMs: Microstructural, mechanical, and thermal properties

Integration of phase change materials (PCMs) into buildings contributes to mitigating indoor temperature fluctuations, offering opportunities for alleviating energy crisis. However, prevalent PCM integration methods commonly suffer from shortcomings in mechanical properties, compatibility, and environmental sustainability, restricting their applications. This study developed a novel shape-stabilized PCM (SSPCM) using cenospheres from coal-fired power waste and bio-based PCMs from vegetable oil by-products, subsequently sealed with silica coatings to inhibit PCM leakage and improve thermal stability, termed as SCS@PCM, exhibiting melting enthalpy up to 103.9 J/g. SCS@PCM was then integrated into cement mortars by replacing fine sand to fabricate thermal storage cement-based materials (TSCM), followed by assessments of their microstructural, mechanical, and thermal properties. The results showed that the silica coating helps to lowrer adverse impact of SCS@PCM on the compressive strength and thermal conductivity of TSCM. TSCM containing 30.0 vol% SCS@PCM reached a 28-day compressive strength of 45.3 MPa, exhibiting only a 17.4 % reduction compared to the control group, notably less than reductions observed for other SSPCMs reported in literature. Moreover, integration of SCS@PCM improved thermal storage capacities and decreased thermal fluctuation rates of TSCM, evidenced by a 4.7 ℃ decrease in peak temperature at dosage of 30.0 vol%. This study endeavors to develop an eco-friendly TSCM with excellent thermal and mechanical properties, providing insights for applications in improving the thermal regulation and energy efficiency in building roofs.

Estimation of preheating time for building intermittent heating subject to changes in outdoor temperature and solar radiation

Intermittent heating is to maintain indoor temperature of buildings in winter within a comfort range only during occupancy periods. Buildings have thermal inertia causing slow increments of indoor temperature, so that a preheating time is required to start heating in advance of occupancy periods. In this paper, a new method is presented to determine preheating time for building intermittent heating subject to changes in outdoor temperature and solar radiation. First, a dynamic model is developed to describe relations between indoor temperature as an output and three inputs including the heating medium temperature, outdoor temperature, and solar radiation. The dynamic model with modeling uncertainties is identified from input-output historical data. Second, the identified model is used to predict indoor temperature under future data of three inputs, and optimal preheating times are determined with a certain probability to ensure successful preheating. The experimental examples show that the dynamic model accurately describes the indoor temperature changes, and the preheating times from the proposed method are more accurate than four existing methods.

Relationship between indoor and outdoor temperature and humidity in a residential building in Central Europe

Relative humidity and temperature in indoor spaces are two important environmental factors that not only determine the behaviour and well-being of building occupants but also influence airborne transmission of respiratory diseases in closed spaces. While recent studies have examined how well indoor conditions relate to outdoor ambient weather, most studies on weather-related health effects still use a single central site monitor such as a weather station since outdoor values are more convenient to measure. However, the correlation between indoor and outdoor values is not always straightforward. Our case study explores the relationships between indoor and outdoor temperature and humidity in a residential building apartment in a temperate climate in Central Europe. Measurements performed over the period of one year allow for a detailed comparison and analysis of correlations between both daily averages as well as daily profiles of indoor and outdoor variables. The results of this case study add further evidence to the observations that day-to-day variation in indoor temperature and relative humidity are not well-represented by outdoor measurements. It further adds to the growing body of data on indoor environmental variables and should thus prove useful in studies aiming to determine the influence of relative humidity and temperature on indoor transmission of airborne diseases as well as in studies examining the influence of these two variables on the well-being of building occupants.

The effect of structural retrofitting and ventilation scenarios on the indoor microclimate of a historical library: The Necip Pasa Library, Turkiye

Structural retrofitting in buildings may result in changes in the indoor microclimate. Chemical, mechanical and biological deterioration can be seen in the cultural properties as a consequence of substrates and inappropriate microclimatic conditions such as high indoor temperature, relative humidity and fluctuations of them. The primary aim of the study is to evaluate the effect of the structural retrofitting, that the building underwent, on the chemical degradation risk of the library collection based on two different ventilation scenarios. One is natural ventilation which is an existing situation since the building is free-floating. The other one implementing a mechanical ventilation system into the building. To be able to compare the microclimate that affects the library collection pre- and post-retrofitting, two models are developed in DesginBuilder and simulated for both scenarios. According to the results of the post-retrofitting model, mechanical ventilation reduced the risk of chemical degradation by 38 %, while natural ventilation did not cause any effect. Natural ventilation gives a similar output in the pre-retrofitting model as in the post-retrofitting model. Mechanical ventilation in the pre-retrofitting model achieves a 33 % reduction in chemical degradation risk. Structural retrofitting only achieves a 1 % reduction in the chemical risk level for both ventilation scenarios. Thus, its effect on the indoor microclimate is insignificant. This study shows that creating simulation models effectively assesses potential risks pre-post-structural retrofitting or any retrofitting in historical buildings. Simulations reveal that mechanical ventilation is a better choice for decreasing chemical degradation risks for the library.

Preparation and investigation of a prefabricated salt hydrate phase change material partition for passive solar buildings

The incorporation of phase change material (PCM) into building structures offers a pathway for passive energy storage, enabling adaptable indoor temperature control and alleviating energy consumption. Despite these advantages, the widespread adoption of PCM in building structures faces challenges due to extended payback periods. In this study, a novel and cost-effective salt hydrate PCM composite, comprised of calcium chloride hexahydrate–potassium chloride (CCH–KCl), was developed. Melamine foam (MF) and strontium chloride hexahydrate (SCH) were synergistically utilized to address phase separation and supercooling issues. Numerical simulations were conducted to assess the performance of the developed salt hydrate PCM composite in building partition walls. Specifically, incorporating a 20 mm-thick composite resulted in peak temperature reductions of 0.72 °C during normal operation and 1.01 °C during power outages compared to structures without PCM, accompanied by a substantial reduction in energy consumption by 5376.68 kWh/year. Moreover, the cost of the developed salt hydrate PCM is 89.33 % lower than industrial paraffin, and it reduces CO2 emissions by 1.40 kg/year/m2 compared to paraffin's 1.11 kg/year/m2. In summary, the developed salt hydrate PCM composite exhibits commendable thermal regulation and economic advantages in building applications, serving as a pivotal contributor to emission reduction efforts.

Integrated gypsum composite material for energy storage and thermal insulation: Assessment of mechanical performance, thermal properties and environmental impact

The development of gypsum-based construction materials with energy storage and thermal insulation functions is crucial for regulating indoor temperatures, reducing building energy consumption, and mitigating CO2 emissions. In this study, graphene and expanded vermiculite (EV) were used as paraffin carriers to prepare a novel dual-carrier composite energy storage material called P/G-EV, which was developed through ultrasound, a constant-temperature water bath, and vacuum adsorption. In addition, a novel energy storage–thermal insulation integrated–gypsum (ESTIIG) composite material was developed using P/G-EV as the energy storage layer (ESL) and EV as the thermal insulation layer (TIL) compounded with phosphorus building gypsum. The thermal properties, mechanics, apparent density, temperature control performance in a real environment and environmental impact of ESTIIG were evaluated, and the temperature control mechanism was analyzed. The results reveal superior thermal stability and thermal conductivity of the P/G-EV carrier.P/G-EV overcomes the low thermal conductivity and leakage problems associated with paraffin, exhibiting a phase change temperature and latent heat of 21.7 °C and 101 J/g, respectively, during the heat absorption stage. In ESTIIG, P/G-EV and EV are compounded with phosphorus building gypsum to form an ESL and a TIL. The overall mechanical performance of ESTIIG meets the requirements of construction applications. Among the variants of ESTIIG, ESTIIG-1, with an ESL/TIL thickness ratio of 3:1, exhibits the best real-world temperature control performance and environmental benefits, providing a more stable and comfortable indoor temperature. Furthermore, this study provides data and theoretical references for the design of ESTIIG through real-world temperature control monitoring and analysis of the temperature control mechanism.

Effectiveness of the Fuzzy Logic Control to Manage the Microclimate Inside a Smart Insulated Greenhouse

Agricultural greenhouses incorporate intricate systems to regulate the internal climate. Among the crucial climatic variables, indoor temperature and humidity take precedence in establishing an optimal environment for plant production and growth. The present research emphasizes the efficacy of employing intelligent control systems in the automation of the indoor climate for smart insulated greenhouses (SIGs), utilizing a fuzzy logic controller (FLC). This paper proposes the use of an FLC to reduce the energy consumption of a greenhouse. In the first step, a thermodynamic model is presented and experimentally validated based on thermal heat exchanges between the indoor and outdoor climatic variables. The outcomes show the effectiveness of the proposed model in controlling indoor air temperature and relative humidity with a low error percentage. Secondly, several fuzzy logic control models have been developed to regulate the indoor temperature and humidity for cold and hot periods. The results show the good performance of the proposed FLC model as highlighted by the statistical analysis. In fact, the root mean squared error (RMSE) is very small and equal to 0.69% for temperature and 0.23% for humidity, whereas the efficiency factor (EF) of the fuzzy logic control is equal to 99.35% for temperature control and 99.86% for humidity control.

Static and dynamic glazing integration for enhanced building efficiency and indoor comfort with thermochromic and electrochromic windows

Effective building energy efficiency requires understanding fenestration’s role in regulating indoor temperatures. Therefore, this study investigates the impact of integrating static glazing with dynamic coatings on building energy efficiency and indoor comfort in a lightweight structure situated in a semi-arid climate. Employing a comprehensive numerical model developed using EnergyPlus and Radiance tools, various static commercial glass window configurations are evaluated to assess their effects on energy consumption, thermal and visual comfort, and economic and environmental considerations. This analysis includes assessments of thermal comfort using PMV and PPD indicators and evaluations of visual comfort based on daylighting and glare metrics. The findings highlight the advantages of incorporating thermochromic and electrochromic films, demonstrating significant improvements in building energy efficiency and interior thermal and visual comfort. Notably, double glazing emerges as the most economically efficient and environmentally viable option, resulting in a reduction of emissions by 1522.38 kgCO2/year, with a payback period of 12.86 years. Furthermore, combining thermochromic and electrochromic coatings with optimal static glazing leads to a remarkable 26 % reduction in energy consumption. These results underscore the potential of dynamic coatings to enhance building energy performance while ensuring occupant comfort. This research approach provides valuable insights into sustainable building design, emphasizing the integrated impact of glazing solutions on energy use, comfort, and environmental sustainability.

Comprehensive assessment of PCM integrated roof for passive building design: A study in energo-economics

There has been a notable surge in energy demand within the building sector of developing nations, particularly in the context of space cooling and heating, which constitute significant portions of energy consumption. The thermal performance of a building’s roof slab plays a crucial role in determining these heating and cooling requirements. To address this, the utilization of Phase Change Material (PCM) to enhance the building’s thermal energy storage capacity has emerged as an innovative strategy for reducing energy demand. This study assesses the thermal behavior of a building envelope integrated with macroencapsulated PCM in a real subtropical environment. Experimental setups include both a conventional slab unit (Ref–SU) devoid of PCM and a PCM (OM37) integrated slab unit (Exp–SU). Analysis entails examining variations in temperature, heat flow, thermal loadings, and maximum heat gain reduction. Economic metrics, such as electricity savings, simple payback periods, and CO2 emissions savings, are also scrutinized. The investigation aims to elucidate the efficacy and underlying parameters governing the PCM’s performance in reducing thermal loads in the Indian city of Rupnagar. Findings indicate that the Exp–SU configuration reduces indoor temperatures by 4.0 °C during sunny hours, resulting in 33.33 % more electricity savings for space cooling compared to heating, with a simple payback period of 5.7 years. Additionally, the heat flux in Exp–SU is reduced by 60.6 % compared to Ref–SU and thermal load by up to 49.8 %. Furthermore, Exp–SU achieves a 44.24 % reduction in CO2 emissions for space cooling compared to heating with a maximum heat gain reduction of 40.3 %.

Field and intervention study on indoor environment in professional classrooms

To study the variation of environment in the professional classroom during lecture hours, multiple field experiments and intervention experiments on indoor and outdoor temperatures were conducted in a university professional classroom in Shaoxing during the spring. Environmental data, including indoor and outdoor temperatures, relative, and CO2 concentrations, were recorded every 5 min. Volatile organic compounds (VOC) were sampled, and indoor air quality was evaluated repeatedly. Results showed that the classroom’s average indoor air temperature ranged from 17.8–29.2 ℃, the average indoor relative humidity from 34.5%–91.0%, the average CO2 concentrations from 921.6–1805.2 ppmv, and total VOC concentrations from 330–682 ppbm. The subjective evaluation conducted during the intervention experiments indicated a significant increase in perceived odor intensity upon entering the classroom. When the CO2 concentration reached 2000 ppmv, the satisfaction and acceptability of the air quality for the subjects and invitees decreased significantly. In the temperature range of 17–31 ℃, the CO2 emission rate of human body was estimated to increase by 0.78 L/h for every 1 ℃ increase in temperature. To maintain the indoor CO2 concentration at 1000 ppmv, the required ventilation rate for each person must be increased by 0.25 ± 0.3 L/s.

Home energy management strategy to schedule multiple types of loads and energy storage device with consideration of user comfort: a deep reinforcement learning based approach

With the increase in the integration of renewable sources, the home energy management system (HEMS) has become a promising approach to improve grid energy efficiency and relieve network stress. In this context, this paper proposes an optimization dispatching strategy for HEMS to reduce total cost with full consideration of uncertainties, while ensuring the users’ comfort. Firstly, a HEMS dispatching model is constructed to reasonably schedule the start/stop time of the dispatchable appliances and energy storage system to minimize the total cost for home users. Besides, this dispatching strategy also controls the switching time of temperature-controlled load such as air conditioning to reduce the energy consumption while maintaining the indoor temperature in a comfortable level. Then, the optimal dispatching problem of HEMS is modeled as a Markov decision process (MDP) and solved by a deep reinforcement learning algorithm called deep deterministic policy gradient. The example results verify the effectiveness and superiority of the proposed method. The energy cost can be effectively reduced by 21.9% at least compared with other benchmarks and the indoor temperature can be well maintained.

Moderating AC Usage Can Reduce Thermal Disparity between Indoor and Outdoor Environments.

In the context of escalating urban heat events due to climate change, air conditioning (AC) has become a critical factor in maintaining indoor thermal comfort. Yet the usage of AC can also exacerbate outdoor heat stress and burden the electricity system, and there is little scientific knowledge regarding how to balance these conflicting goals. To address this issue, we established a coupled modeling approach, integrating the Weather Research and Forecasting model with the building energy model (WRF_BEP + BEM), and designed multiple AC usage scenarios. We selected Chongqing, China's fourth-largest megacity, as our study area due to its significant socioeconomic importance, the severity of extreme heat events, and the uniqueness of its energy infrastructure. Our analysis reveals that AC systems can substantially reduce indoor temperatures by up to 18 °C; however, it also identifies substantial nighttime warming (2-2.5 °C) and a decline in thermal comfort. Particularly for high-density neighborhoods, when we increase 2 °C indoors, the outdoor temperature can be alleviated by up to 1 °C. Besides, despite the limited capacity to regulate peak electricity demand, we identified that reducing the spatial cooled fraction, increasing targeted indoor temperature by 2 °C, and implementing temporal AC schedules can effectively lower energy consumption in high-density neighborhoods, especially the reduction of spatial cooled fraction (up to 50%). Considering the substantial demand for cooling energy, it is imperative to carefully assess the adequacy and continuity of backup energy sources. The study underscores the urgency of reassessing energy resilience and advocates for addressing the thermal equity between indoor and outdoor environments, contributing to the development of a sustainable and just urban climate strategy in an era of intensifying heat events.

Innovative house structures for malaria vector control in Nampula district, Mozambique: assessing mosquito entry prevention, indoor comfort, and community acceptance.

Insecticide-treated mosquito bed nets and indoor residual spraying are widely used for malaria vector control. However, their effectiveness can be affected by household members' habits, requiring alternative approaches toward malaria vector control. To assess the effectiveness of modified houses in preventing mosquito entry; to assess the impact of house modifications on indoor air conditions and evaluate the acceptability of modified houses in the community where the study was conducted. Five traditional and five modified houses were constructed in Nampula district, Mozambique and underwent a 90-day overnight indoor mosquito collection using Centers for Disease Control and nitride ultraviolet light traps during the rainy season. Mosquitoes were identified morphologically. Indoor temperature, relative humidity, carbon dioxide levels and wind speed were also collected. The Student's t-test was used to compare the means of the number of mosquitos and environmental factors between both house types. A binomial form of the Generalized Linear Model identified the factors associated with the community volunteer's preference for house type. Modified houses reduced the number of Anopheles by an average of 14.97 mosquitos (95% CI, 11.38-18.56, p < 0.000) and non-Anopheles by 16.66 mosquitoes (95% CI, 8.23-25.09, p < 0.000). Although fewer mosquitoes were trapped in modified houses compared to traditional ones, the modifications were more effective against Anopheles (94% reduction) than for non-Anopheles (71% reduction). The average temperature increased at 0.25°C in modified houses but was not statistically significant (95% CI, -0.62 to 0.12, p = 0.181). Community volunteers preferred modified houses due to reduced mosquito buzzing. The efficacy of modified houses including its acceptability by community, highlight its potential to lower malaria risk. Effective integration of modified houses into the vector control strategy will require raising awareness among communities about malaria risks associated with house structure and training them to modify their houses.

Overcooling in UAE homes: health issues and implications for learning efficiency

From 1990 to 2016, , air conditioning usage in the UAE increased from 25 to 125 terawatt hours, making up 70% of the country's electricity consumption. Overcooling to 18°C in homes is common, leading to health issues and reduced learning efficiency during the Covid-19 pandemic. This study uses Electroencephalograms (EEG) to examine indoor thermal environments' impact on learning efficiency. An artificial climate chamber set at 24°C or 20.5°C monitored 64 healthy males aged 21–29 during a 70-minute EEG session. Participants took a Visual Continuous Performance test and had their academic performance evaluated. Seven brain areas were analyzed for attention and power frequency. Results showed lower temperatures (20.5°C) increased EEG frequency, indicating better attention than 24°C. Statistical analysis revealed that concentration was achieved faster at lower temperatures. This study highlights the importance of optimizing indoor temperatures for improved learning efficiency and well-being.

Green roof thermal performance of small-scale prototype using IES-VE simulation in tropical climatic condition

Abstract This study investigates the thermal performance of green roof systems in a tropical climate, focusing on the small-scale building prototypes. Batu Pahat, Malaysia is experiencing the increasing temperatures due to climate change. Green roofs are considered as a potential solution, but their effectiveness depends on various factors such as building orientation, solar shading, and thermal resistance (R-value). Therefore, modeling and simulation are crucial for understanding green roof thermal behaviour. This study employs the Integrated Environmental Simulation Virtual Environment (IES-VE) software for analysis. Three identical small-scale buildings were constructed, one with Portulaca Grandiflora (PGR) plants, another with Alternanthera Paronychioides (ATN) plants, and a control roof with no vegetation. The R-values from the on-site green roofs were measured at 0.8899 m²K/W for PGR and 1.1477 m²K/W for ATN, while the control roof had an R-value of 0.1 m²K/W. Green roofs with higher R-values demonstrated a substantial reduction in indoor temperatures, making them a valuable solution for improving thermal comfort in tropical climates. This study underscores the importance of green roofs in mitigating rising temperatures in tropical climates. Simulation using IES-VE approved that green roofs can potentially reduce indoor temperatures, demonstrating their suitability for tropical regions. These findings have significant implications for sustainable building design and urban planning in hot and humid climates.