Outdoor Environmental Conditions Research Articles

Public and Private Economic Feasibility of Green Areas as a Passive Energy Measure: A Case Study in the Mediterranean City of Trapani in Southern Italy

Green infrastructure in urban environments provides a wide range of ecological, social, aesthetic, and health co-benefits. Urban plant covers in particular contribute to improved outdoor environmental conditions that, in turn, influence the energy behavior of buildings and their indoor thermo-hygrometric comfort performance. Within this context, this study illustrates a methodology aimed at verifying the economic feasibility of alternative types of green areas for public and private stakeholders, which are analyzed as passive energy measures. Therefore, our methodology integrates approaches from different disciplines and consists of a microclimatic analysis of different vegetation scenarios and of the outdoor comfort level, an evaluation of the energy needs of a sample of houses, and an economic feasibility estimation considering different scenarios and public and private investors. The methodology is illustrated through its application to a suburban district of the Sicilian city of Trapani in the South of Italy, considered representative of Mediterranean climate conditions. Results showed significant differences between the scenario outcomes depending on the type of vegetation used in the green areas and put in evidence how economic feasibility for some stakeholders may be achieved in the management phase if adequate incentives equal to the planting cost are assumed.

Evaluation of thermal comfort in mixed-mode buildings in temperate oceanic climates using American Society of Heating, Refrigeration, and Air Conditioning Engineers Comfort Database II

A comprehensive understanding of occupant comfort in mixed-mode (MM) buildings is crucial for the design of MM buildings which are being proposed as a low-energy solution to combat the global warming without compromising comfort. Current comfort standards are mainly for naturally ventilated (NV) or air-conditioned (AC) buildings, and there is a significant gap in standards for MM buildings. With comfort databases playing a major role in the development of thermal comfort models, the recently published ASHRAE Global Thermal Comfort Database II is utilised, in this research, to investigate the thermal sensation and occupant’s behavioural adaptations in MM buildings in temperate oceanic climates and to develop an adaptive thermal comfort model based on the outdoor environmental conditions. The Fanger's PMV model was found to underpredict the actual thermal sensation of the occupants while the occupant adaptivity was found to be lower than that predicted by the adaptive models of Standard 55 and EN15251/EN 16798-1. Furthermore, based on the results of this study and the various impediments faced, recommendations are proposed for future comfort surveys so that more detailed and conclusive studies can be conducted for wider applications using open-source thermal comfort databases. Good understanding of occupant comfort is necessary to reduce building energy consumption without compromising comfort. This article explores the use of ASHRAE Comfort Database II for determining occupant comfort in MM buildings in temperate oceanic climates and the limitations faced therein. A practical and publicly accessible database developed based on the recommendations from this study will improve thermal comfort models and enable better prediction of occupant comfort while improving energy efficiency substantially.

A New Wearable System for Sensing Outdoor Environmental Conditions for Monitoring Hyper-Microclimate.

The rapid urbanization process brings consequences to urban environments, such poor air quality and the urban heat island issues. Due to these effects, environmental monitoring is gaining attention with the aim of identifying local risks and improving cities’ liveability and resilience. However, these environments are very heterogeneous, and high-spatial-resolution data are needed to identify the intra-urban variations of physical parameters. Recently, wearable sensing techniques have been used to perform microscale monitoring, but they usually focus on one environmental physics domain. This paper presents a new wearable system developed to monitor key multidomain parameters related to the air quality, thermal, and visual domains, on a hyperlocal scale from a pedestrian’s perspective. The system consisted of a set of sensors connected to a control unit settled on a backpack and could be connected via Wi-Fi to any portable equipment. The device was prototyped to guarantee the easy sensors maintenance, and a user-friendly dashboard facilitated a real-time monitoring overview. Several tests were conducted to confirm the reliability of the sensors. The new device will allow comprehensive environmental monitoring and multidomain comfort investigations to be carried out, which can support urban planners to face the negative effects of urbanization and to crowd data sourcing in smart cities.

Experimental study on tilting behavior and blow out of dual tandem jet flames under cross wind

Fire hazards in outdoor environmental conditions cause huge damage to process safety in fuel transportation and pipeline leakage. Few literatures are reported about the combustion behaviors and instability characteristics of dual jet flames under cross wind, which are important to risk assessment and manufacturing design. In this work, a series of propane fire source with nozzle diameters of 3 mm, 4 mm and 5 mm are designed for different nozzle separation distances under cross wind. Results showed the tilt angle of rear jet flame was smaller than front jet flame due to the vitiated effective wind towards the rear jet flame by the blockage of the front jet flame. Furthermore, it’s found that the blow-out cross wind velocity of the rear jet flame is smaller than that of the corresponding single jet flame. The combustion of the front jet flame will restrict the rear jet flame to a certain extent. Finally, dimensional analysis and correlations are established, where the blow-out cross wind velocity of rear jet flame as well as that of the single jet flame can be well represented by Froude number. These new observations and correlation are helpful for further understanding combustion behaviors of dual tandem jet flames under cross wind.

Determination of 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanone (NNK) arising from tobacco smoke in airborne particulate matter

The most important tobacco-specific nitrosamine found in cigarette smoke and formed in ageing smoke after cigarettes are extinguished is 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). It is formed from nitrosation of nicotine, under particular conditions both in indoor and outdoor environments. NNK has been classified as a potent lung carcinogen which is expected to be found primarily in the particle-phase and to be stable in particulate matter. In this study tests have been carried out to show that a bisulfate-treated filter is more efficient than an untreated filter to collect both nicotine and NNK, and that the latter is stable in outdoor particulate matter. To characterize NNK in the outdoor environment, airborne samples were collected from 11 cities in USA, UK, Hong Kong and Malta with characteristics varying from low to high population densities and from urban to suburban to rural, and with desert characteristics and distinct climates. It has been shown that airborne particle + gas phase nicotine and particle-phase NNK behave in a linearly correlated manner. A seasonal analysis was carried out on a subset of data available from five sites in California, where the load of NNK in PM10 is driven by long range transport of the air masses passing over densely populated cities. In the winter season, the load of NNK in PM is higher than in summer in a statistically significant manner. The contamination of PM with NNK shows variability, but is observed at all sites. This paper highlights the potential risk of chronic exposure to NNK in particulate matter by the inhalation pathway.

HVAC energy savings, thermal comfort and air quality for occupant-centric control through a side-by-side experimental study

Building sensing technologies have evolved rapidly in the last two decades in aid of monitoring building environment and energy system performance. A series of occupancy sensing systems were developed to track the occupant behavior in the indoor space. Occupancy-based building system control is defined as a control method that adjusts the building system operation schedules and setpoints based on the measured occupant behavior and has been identified as a smart building control strategy that can improve building energy efficiency as well as occupant comfort. Some studies demonstrated energy-saving potential and comfort-maintaining capability from occupancy-based control. This study adopted a first-of-its-kind side-by-side experimental approach to quantify the performance of the occupancy-based control in commercial buildings. Three state-of-the-art occupancy sensing technologies were integrated into the real-time Heating, Ventilation, and Air-Conditioning (HVAC) system control in this study. Their detection accuracy and its effectiveness on energy-saving and thermal comfort were analyzed. It was found that the occupancy-based control can maintain good thermal comfort and perceived indoor air quality with a satisfaction ratio greater than 80%. Although the daily energy-saving varied with occupancy sensor accuracy and outdoor environment conditions, the weekly averaged energy saving was between 17 and 24%.

Shrinkage behavior of cementitious 3D printing materials: Effect of temperature and relative humidity

Extrusion-based concrete 3D printing is at its infancy and many aspects of this new technology need to be thoroughly investigated to pave the way for its widespread use in construction. Since the inherent drying shrinkage of the hardened cement paste is the source of the drying shrinkage of 3D printed concrete, the shrinkage behavior of cementitious 3D printing materials with very high cement to fine aggregate ratios is one of the major challenges for researchers working on this innovative technology. Besides, due to the absence of formwork in this technique, an outdoor 3D printing environment causes excessive moisture loss and drying shrinkage cracking. This paper presents the first comprehensive investigation on the effects of different outdoor environmental conditions i.e. relative humidity (RH) and temperature on the moisture loss, drying and autogenous shrinkage of cementitious 3D printing materials, considering different sand to cement (S/C), and surface to volume (S/V) ratios of free-formed specimens. Mass loss and length change of mortars which were cured for up to 168 days under standard condition (24 ̊C-50%RH with 24 h of sealed initial curing) were compared with those at 24 ̊C-50%RH, 35 ̊C-85%RH and 35 ̊C-45%RH (free-formed specimens without initial curing) to investigate the effect of outdoor printing environment and the absence of formworks on the deformations caused by shrinkage. The drying shrinkage results indicate that 28 days free-formed specimens under different non-standard curing conditions show a length change up to 30% lower than specimens in the standard environment. Moreover, increasing the sand to cement ratio from 0.8 to 1.0 results in a 10% decrease in the drying shrinkage strain. This study also discusses the higher susceptibility of free-formed specimens to carbonation shrinkage and demonstrates that printed specimens have higher shrinkage deformation in the longer term compared to conventional casting specimens. The results of nitrogen adsorption-desorption analysis also prove that the total porosity in free-formed specimens in all environmental conditions reduces and reaches a finer pore structure after 112 days compared to conventional casting specimens. These results point to the importance of internal or external curing for reducing shrinkage in concrete 3D printing.

Exercise under Exposure to Air Pollution and Spirometry in Healthy Adults with and without Allergy

Ambient air pollution is a major environmental threat to human health. The acute effects of exposure to ambient air pollution during physical exercise may depend on allergy status. The aim of the study was to assess the acute respiratory responses to air pollution exposure during physical training in young adults with and without allergies. The studied group included 71 healthy young adults (n = 16 with allergy and n = 55 without allergy). Students completed two indoor physical training trials lasting 45–60 min: when air pollutants concentrations were high (exposure trial) and low (control trial). During each trial, we monitored outdoor and indoor environmental conditions. Participants performed spirometry at baseline and directly after the exercise. Exercise during exposure trials led to a small decrease in the percentage of predicted forced expiratory volume in 1 s (FEV1 ref). Only during the control trials did the FEV1/forced vital capacity quotient (FEV1/FVC) statistically significantly increase. Moreover, just in the allergy group, there were statistically significant negative correlations between post-exercise FEV1/FVC change and 3 h average outdoor particulate matter with aerodynamic diameter <10 µm (PM10) and nitrogen dioxide (NO2) concentrations (PM10: r = −0.54, p = 0.02, NO2: r = −0.60, p = 0.02). In young and healthy adults, sports training under exposure to high levels of ambient air pollutants leads to a small decrease in FEV1. The allergy might be a modifying factor in the respiratory responses to air pollution. Post-exercise decrease in FEV1/FVC was related to pre-exercise 3 h averages of PM10 and NO2 only in people with ever-diagnosed upper-respiratory allergy.

Experimental and Computational Model for a Neonatal Incubator with Thermoelectric Conditioning System

This work describes the design, construction and testing of a thermo-electric conditioning device installed in a neonatal incubator with the aim of improving the precision in the regulation of the interior air temperature, reducing noise and interior vibration, and improving the life of the neonate. A simplified one-dimensional thermal model has been developed, made up of resistances and thermal capacities that simulate the thermal behaviour of all the elements of the system from end to end. All the equations of the model are obtained in a nodal way, allowing the mathematical relationship between the input and output to be known. This model makes it possible to improve temperature control, avoiding the deviations that occur in the traditional model controlled by sensors at both ends. The computational model allows to predict the variation of temperatures in transient and permanent regime. This model allows the design and sizing of the thermoelectric system for different outdoor environmental conditions and the selection of the number of Peltier modules needed to satisfy the heating demand of other incubators with different geometry and capacity. The results of the computational model show good agreement with the experimental tests, despite being a simplified 1D nodal model. The results obtained show a coefficient of operation (COP) of 1.38, achieving higher performance than the current traditional electrical resistance system (COP = 1). In addition, a CFD study has been carried out to check the air patterns, to see the temperature uniformity and to estimate the number of air changes per hour (HVAC) inside the incubator.

Detailed thermal indicators analysis based on outdoor thermal comfort indices in construction sites in South China

Extreme thermal environment harms the health of outdoor workers and poses a potential threat to workplace safety. A field survey, including thermal parameter measurements, was conducted at construction sites in South China during the summer of 2019. The relationship between health risk and thermal parameters was obtained. The thermal sensation and satisfaction rate of the workers at different outdoor environmental conditions were analyzed, and recommendations were made based on the comparison of thermal indices. The thermal stress categories of the thermal indices were also investigated. The results suggest that the intensity of working conditions should be reduced when the air temperature is higher than 34 °C; the satisfaction rate of workers was found to be relatively high when the outdoor temperature is lower than 34 °C and the wind speed is greater than 1.3 m/s. Thermal indicators used to evaluate the comfort level of outdoor workers need to be modified according to the local climate and working environment to avoid excessive exposure to high-temperature work environments.

Comparative Study on the Measurement and Analysis Methods of Heart Rate Variability in Human Body for Occupants’ Thermal Comfort Evaluation by Considering Physiological Response

Thermal comfort in humans has been evaluated using predicted mean vote (PMV) based on factors such as clothing and activity levels of an individual to address their satisfaction with the thermal environment. However, PMV does not consider the physiological and psychological factors associated with thermal comfort. A person may feel dissatisfied in an environment that is thermally comfortable for others; this can be calculated by applying heart rate variability (HRV) to the comfort index by measuring the ECG data of the body. Currently, various types of wearable IoT sensors are available for measuring HRV characteristics. In this study, we analyzed the HRV parameters in the human body to evaluate the thermal comfort of the occupant. A data measurement and analysis method using different HRV sensors was developed to determine the feasibility of HRV as a physiological response to the thermal comfort model of the occupant. The characteristic changes in the measured HRV values were analyzed in standard indoor and outdoor environmental conditions.

A Multi-Sensor Environmental Perception System for an Automatic Electric Shovel Platform

Electric shovels have been widely used in heavy industrial applications, such as mineral extraction. However, the performance of the electric shovel is often affected by the complicated working environment and the proficiency of the operator, which will affect safety and efficiency. To improve the extraction performance, it is particularly important to study an intelligent electric shovel with autonomous operation technology. An electric shovel experimental platform for intelligent technology research and testing is proposed in this paper. The core of the designed platform is an intelligent environmental sensing/perception system, in which multiple sensors, such as RTK (real-time kinematic), IMU (inertial measurement unit) and LiDAR (light detection and ranging), have been employed. By appreciating the multi-directional loading characteristics of electric shovels, two 2D-LiDARs have been used and their data are synchronized and fused to construct a 3D point cloud. The synchronization is achieved with the assistance of RTK and IMU, which provide pose information of the shovel. In addition, in order to down-sample the LiDAR point clouds to facilitate more efficient data analysis, a new point cloud data processing algorithm including a bilateral-filtering based noise filter and a grid-based data compression method is proposed. The designed platform, together with its sensing system, was tested in different outdoor environment conditions. Compared with the original LiDAR point cloud, the proposed new environment sensing/perception system not only guarantees the characteristic points and effective edges of the measured objects, but also reduces the amount of processing point cloud data and improves system efficiency. By undertaking a large number of experiments, the overall measurement error of the proposed system is within 50 mm, which is well beyond the requirements of electric shovel application. The environment perception system for the automatic electric shovel platform has great research value and engineering significance for the improvement of the service problem of the electric shovel.

Novel Integrated and Optimal Control of Indoor Environmental Devices for Thermal Comfort Using Double Deep Q-Network

Maintaining a pleasant indoor environment with low energy consumption is important for healthy and comfortable living in buildings. In previous studies, we proposed the integrated comfort control (ICC) algorithm, which integrates several indoor environmental control devices, including an air conditioner, a ventilation system, and a humidifier. The ICC algorithm is operated by simple on/off control to maintain indoor temperature and relative humidity within a defined comfort range. This simple control method can cause inefficient building operation because it does not reflect the changes in indoor–outdoor environmental conditions and the status of the control devices. To overcome this limitation, we suggest the artificial intelligence integrated comfort control (AI2CC) algorithm using a double deep Q-network(DDQN), which uses a data-driven approach to find the optimal control of several environmental control devices to maintain thermal comfort with low energy consumption. The suggested AI2CC showed a good ability to learn how to operate devices optimally to improve indoor thermal comfort while reducing energy consumption. Compared to the previous approach (ICC), the AI2CC reduced energy consumption by 14.8%, increased the comfort ratio by 6.4%, and decreased the time to reach the comfort zone by 54.1 min.

Different Façade Types and Building Integration in Energy Efficient Building Design Strategies

Building façades play a major role in improving the effects of outdoor environment conditions on indoor comfort conditions. Façades, which are designed as energy efficiency, are created according to different performance parameters and can offer solutions appropriate for the climatic condition. This paper aims to describe and highlight the role of design and application determinants in building façade types according to energy efficiency in different climatic classes. For this purpose, 12 building façade types in different climate types were investigated and analyzed by a purposive or judgmental sampling technique. Façade analyses have been carried out by considering double skin, adaptive, photovoltaic panel, vertical green, media and structural membrane façades created as a result of developing technological opportunities. Balance of heat loss and gain, preventing overheating, providing daylight and natural ventilation, active and mechanical solutions for climate-sensitive, noise control, recycling and evaluating the initial investment cost are presented. With examinations, it has been determined that different façade systems are innovative construction systems in creating energy efficiency. It has been concluded that the effect of improving indoor comfort conditions of the building by controlling the outdoor environment conditions with the construction of different facade systems is very important in the architectural process. With the development of technology and smart systems, the impact of the façades on the climate analysis and energy efficient design strategies will be much more important in the future

Experimental performance evaluation of weak turbulence channel models for FSO links

Outdoor wireless communication is subject to several outdoor environment conditions. Among them, atmospheric turbulence which happens on a daily basis, introduces signal fading and degrades the system performance. Many channel models have been proposed in the literature to model the turbulence fading in free space optic (FSO) communication systems. In this work, we aim to evaluate the performance of some key proposed channel models for FSO systems under weak turbulence condition. First, an outdoor experimental setup is utilized to measure the turbulence fading and build a dataset. The setup is all-optical, which gives us the advantage of isolating the solar radiation noise during measurements. Second, the obtained dataset is used to investigate the performance of five key FSO channel models claimed to perform well under weak turbulence conditions. The results show that for very weak turbulence with scintillation index (SI) <10−3, four models that claim to work well under such condition failed to fit the dataset. For weak turbulence with SI>10−3, all the models fit the dataset except I-K model. Third, we exploited the obtained dataset to propose a new empirical channel model that has good performance under weak turbulence conditions. Using this model, we studied the outage probability of FSO system under the joint effect of weak turbulence and fog attenuation.

Business Processes and Comfort Demand for Energy Flexibility Analysis in Buildings

Occupant behavior and business processes in a building environment constitute an inseparable set of important factors that drives energy consumption. Existing methodologies for building energy management lag behind in addressing these core parameters by focusing explicitly on the building’s structural components. Additional layers of information regarding indoor and outdoor environmental conditions and occupant behavior patterns, mostly driven by everyday business processes (schedules, loads, and specific business activities related to occupancy patterns and building operations), are necessary for the effective and efficient modeling of building energy performance in order to establish a holistic energy efficiency management framework. The aim of this paper was to develop a context-driven framework in which multiple levels of information regarding occupant behavior patterns resulting from everyday business processes were incorporated for efficient energy management in buildings. A preliminary framework evaluation was performed in a multifaceted university building involving a number of spaces, employees, business processes, and data from sensors and metering devices. The results derived by linking operational aspects and environmental conditions (temperature, humidity, and luminance) to occupant behavior underlying business processes and organizational structures indicated the potential energy savings: a max of 7.08% for Heating, ventilation, and air conditioning (HVAC), 19.46% for lighting and a maximum of 6.34% saving related to office appliances.

Pedestrian tracking in thermal videos using TFM (tri-feature matrix)

Nowadays, thermal cameras play a major role because of its temperature-based photography in many applications such as video surveillance, monitoring electronics/electrical machines, forest monitoring, monitoring babies/adult patients, and suspicious object detection. Tracking pedestrians in thermal video is a major task for such applications. Thermal cameras usually create images based on temperature emitted by the object only and not on the lighting conditions and outdoor environment conditions. But still thermal images have constraints like no texture or colour information, more number of dead pixels, low resolution, and noticeable visual colour patterns in case of any temperature variations. So the challenge in tracking pedestrians in thermal videos is tracking objects/pedestrians throughout the video without an identity switch by overcoming these constraints which may mislead the tracking process. To overcome these constraints, the proposed system uses tri feature matrix (TFM) as an object descriptor which is used to uniquely identify and represent objects in thermal images. TFM is represented in more compact way as a triple matrix. It is a simple and accurate descriptor suitable for tracking objects in thermal video sequences without an identity switch. The proposed Pedestrian tracking system uses most of the advantages of thermal cameras by overcoming challenges in thermal videos effectively based on a novel descriptor TFM. The proposed system is evaluated with various data sets, and the results are analysed using true positive, true negative, false negative, false positive, accuracy, precision, recall, F-score, global identity mismatch (GMME) and track matching error (TME). The performance metrics such as accuracy, precision, recall, F-score, GMME and TME are computed as 99%, 100%, 99%, 99%, 2.3%, and 2.1%, respectively. From the observation, it is found that the performance of proposed TFM-based system is significantly improved. The experimental result shows that the proposed system achieved more accurate tracking compared to the conventional methods.

Semi real-time detection of subsurface consolidation defects during concrete curing stage

Subsurface consolidation defect is a common issue in concrete pavement construction, and the hidden defects often require costly repairs after project delivery. Therefore, being able to identify this type of defect during construction will enable contractor to conduct quick repairs to avoid costly post-construction rework. In this paper a semi real-time detection approach using infrared thermography is introduced. The developed approach utilizes the hydration heat during curing time to identify the subsurface voids based on the regional temperature contrast. Experimental studies were conducted using artificial void-defect in different sizes and depths. The thermographic analysis is employed to locate the void-defects during the first 12 h of curing time. Two field experiments were conducted to validate the proposed approach. The outcomes show that the defects could be identified and located within certain time windows during the curing process, even under adversary outdoor environmental conditions. In conclusion, infrared thermography can be used as a feasible and reliable non-destructive-detection method to conduct real-time or semi real-time monitoring of subsurface defects during concrete pavement construction. The influential environmental factors, practical considerations, and the future study are also discussed.

Canan Outdoor Multisurface Terrain Enhance the Effects of Fall Prevention Exercise in Older Adults? A Randomized Controlled Trial

Walking on complex surface conditions in outdoor environments is important for active aging. This study aimed at examining whether fall prevention exercise integrated with an outdoor multisurface terrain compared with indoor solid ground was more beneficial for older adults. Twenty-two older nursing home residents were randomly assigned to outdoor multisurface terrain (n = 11, 79.5 ± 2.1 years) or indoor solid ground (n = 11, 78.8 ± 5.2 years) groups. Training occurred five times per week (30 min) for 3 weeks. The following performance test outcomes were measured: 10 m walk test (10 mWT), multisurface terrain walk test (MTWT), 2 min walk test (2 MWT), timed up and go test (TUGT), single-leg standing test with eyes open (SLSTEO), single-leg standing test with eyes closed (SLSTEC), and closed cycles test (CCT). Compared with baseline, the outdoor multisurface terrain training significantly improved performance in all tests (p < 0.01). The improvements of the outdoor multisurface terrain group after intervention were significantly higher than those of the indoor solid group in the 10 mWT (p = 0.049), MTWT (p = 0.02), and 2 MWT (p = 0.000). Exercise combined with outdoor multisurface terrain training may be an efficacious approach and a feasible environmental intervention for fall prevention in older adults.

DSF studies towards energy efficiency for a tall building design in the Mediterranean climate

Tall buildings around the world are increasing at an accelerating pace. However, this fast-pace development is not in tandem with today’s environmental considerations towards reducing high carbon emissions, mainly relating to the building sector (close to 50% of carbon dioxide (CO2) emissions). The vast scale and energy demands of tall buildings call for an in-depth study of this building typology towards improving energy efficiency. An important consideration for lowering energy demands is the configuration of the building envelope that acts as the mediator between indoor and outdoor conditions, according to the climate and microclimate of the building’s location. Current architectural practices of fully glazed curtain wall envelopes make this relationship problematic, by resulting in high-energy loads for achieving thermal comfort. Over the last few years, a step forward towards energy efficiency is the use of a double-skin façade (DSF). Its application, however, is lacking consideration of the specific climatic conditions that will essentially result in an energy efficient design. Previous research revealed that the most energy efficient DSF in the Mediterranean climate is with LowE glazing as the outside DSF layer. Further studies on DSF cavity width for a hot climate, were in favour of wider cavities, as these reduce the high cooling loads that are associated with this climate. Additionally, simulations of an office building in the Mediterranean climate, confirmed that cooling energy is also present during winter (airtight DSF), suggesting for a more active DSF envelope design throughout the year. A further study is then conducted through simulations, where the DSF design alternates between an open / closed DSF, and comparisons are made in relation to DSF width, building height above ground, outdoor environmental conditions and interior thermal comfort, for further improving the energy efficiency of tall building design.