January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
The 2010 Earthquake in Haiti caused catastrophic damage to the metropolitan area of Port au Prince. The earthquake destroyed approximately 105,000 homes, causing more than 2.3 million people to live as Internally Displaced Persons (IDPs). Today, more than 1.3 million people still live in tents. Low cost buildings can provide a housing solution for these people. This paper proposes a low cost building solution intended for hot climates, using concrete as the only material. Due to the lack of facilities at these locations, no conventional energy or cooling systems can be installed; thus, only passive cooling technologies can be used to increase thermal comfort. A low cost cool roof and combined natural ventilation is proposed, and simulations show an improvement of 16% in the thermal conditions inside the building. The simulation is performed using the software package EnergyPlus and shows that cool roofs can be a good solution for improving living conditions in low cost houses for IDPs.
Highlights
► A low cost building solution for IDPs in hot climates is studied and simulated. ► Thermal conditions are improved with no use of HVAC system. ► Passive climatization systems allows increasing thermal comfort. ► Cool roof and natural ventilation increases thermal comfort up to 16%. ► The solution is simulated for Haiti Earthquake IDPs obtaining good results.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Nowadays, the majority of people carry on their daily activities inside a building. This has motivated research directed to assure several comfort conditions. Thermal comfort is usually maintained by means of HVAC (Heating, Ventilation and Air Conditioning) systems. The most widely used thermal comfort index is the PMV (Predictive Mean Vote), which is computed considering measurements of several physical variables. The classical calculation of this index is expensive in computational terms, and the involved measurement requires a relatively extensive sensor network. This work proposes the use of two approximated models for the PMV index, one is based on an artificial neural network and the other makes use of polynomial expansions, aimed at using these approximated indices within model predictive control frameworks. In this context, the advantages of using approximated models are two-fold: the computational cost of the calculation of the index is reduced, allowing its use in real-time control of HVAC systems; and the network sensor size is decreased. These advantages entail economic benefits and promote the deployment of comfort controllers in larger structures. This paper illustrates the development of the above cited approximated models and includes experimental tests that rate the accuracy and benefits of the proposed models.
Highlights
► We calculated two different model approximations in order to model the PMV index. ► One approximation is based on neural networks and other is calculated through a polynomial. ► We tested both approximations with several real data-sets in order to check their efficiency. ► Both approximations are able to reproduce the PMV index dynamics. ► These approximations can be used in an easily way by controllers to maintain users' thermal comfort.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Green roof plants alter the microclimate of building roofs and may improve roof insulation. They act by providing cooling by shading, but also through transpiration of water through their stomata. However, leaf surfaces can become warmer when plants close the stomata and decrease water loss in response to drying substrate (typically associated with green roofs during summers), also reducing transpirational cooling. By using a range of contrasting plant types (Sedum mix – an industry green roof ‘standard’, Stachys byzantina, Bergenia cordifolia and Hedera hibernica) we tested the hypothesis that plants differ in their ‘cooling potential’. We firstly examined how leaf morphology influenced leaf temperature and how drying substrate altered that response. Secondly, we investigated the relationship between leaf surface temperatures and the air temperatures immediately above the canopies (i.e. potential to provide aerial cooling). Finally we measured how the plant type influenced the substrate temperature below the canopy (i.e. potential for building cooling). In our experiments Stachys outperformed the other species in terms of leaf surface cooling (even in drying substrate, e.g. 5 °C cooler compared with Sedum), substrate cooling beneath its canopy (up to 12 °C) and even – during short intervals over hottest still periods – the air above the canopy (up to 1 °C, when soil moisture was not limited). We suggest that the choice of plant species on green roofs should not be entirely dictated by what survives on the shallow substrates of extensive systems, but consideration should be given to supporting those species providing the greatest eco-system service potential.
Highlights
► Of all the species tested, leaf surface temperature was lowest in Stachys, even when water was limited. ► On warm days, both Stachys and Sedum cooled the air above the substrate compared to bare soil. ► On several hot afternoons in the glasshouse Stachys provided more aerial cooling than other species. ► In outdoor conditions we recorded one incidence where Stachys provided additional localised aerial cooling. ► On a warm day, temperatures below Stachys and Sedum canopies were 11 °C and 4 °C lower than of bare soil.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
The optimal human body thermal conditions for comfortable sleep differ significantly from the optimal body thermal conditions for being awake. With the body covering such as a blanket representing a higher insulation value than the typical indoor attire suggests that a significant indoor temperature reduction during sleep may be available.With known skin temperature and heat loss rate required for comfortable sleep, a numerical model was developed for a 50th percentile male to calculate the desired thermal environment for sleep. The results show that the thermal environment represented by the operative temperature of the room can be reduced to around 15 °C to maintain sleep thermal comfort. This is significantly less than the thermal environment required by the building codes and ASHRAE comfort standard, which suggests that the heating system output may be reduced, which translates to potential energy savings and improved quality of thermal environment for sleep thermal comfort.As a part of a field study, data collected from a radiant ceiling heated house show that the operative temperatures exceed the desired thermal environment conditions for comfortable sleep. A calculation on the peak heating day with the building characteristics was performed with reduced heating set points during sleep. It was found that up to 10% of the heating energy may be reduced. The eQuest energy simulations show that an approximately 2% saving in total space heating demand can be achieved for 1 °C set-point reduction during the 8 h nighttime.
Highlights
► A model was developed to calculate the desired thermal environment for sleep. ► Typical indoor temperature set points will likely overheat a sleeping body. ► Operative temperatures in a radiant heated house exceed desired condition for sleep. ► Up to 10% heating energy may be saved with reduced set points for the study house.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Buoyancy driven flow between two finite zones containing fluid of slightly different density is investigated. The two zones are connected through a common rectangular doorway spanning the channel width so that a two-layer exchange flow develops once the barrier is removed. In the zone that initially contained dense fluid, a buoyant plume of light fluid mixes with the dense fluid leading, over time, to the development of non-trivial ambient density stratification. Meanwhile, dense fluid flows as a gravity current into the zone that initially contained light fluid. This gravity current reflects from the end wall and propagates back toward the opening in the form of an internal bore. When the bore reaches the opening the dynamics of the exchange flow (and consequently the source conditions of the buoyant plume) are substantially altered. Such dynamics are modeled using elements of gravity current, internal bore and plume theory. The flow dynamics of the two zones are linked using two-layer exchange flow theory whereby a maximal exchange flow rate is prescribed only before the bore reaches the opening. The velocity and density jump across the first front decrease substantially once the exchange flow becomes sub-maximal. Depending on the geometrical parameters, the terminal elevation of the first front may lie above, at or below the top of the opening; here, we focus on the former scenario. Experiments have been carried out to validate the model. The comparison between theory and experiment plus the application of the research to architectural fluid mechanics is discussed.
Highlights
► The exchange flow between building zones of different temperature is modeled. ► We study the transient, coupled evolution of the zonal density profiles. ► The density jump across the first front decreases abruptly after a certain point. ► Similitude laboratory experiments are conducted for validating model predictions. ► Good agreement with experiments is noted for a wide range of geometrical parameters.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Tuberculosis (TB) is among the top ten causes of death worldwide. The impacts of potential control measures on TB infection in senior care facilities are poorly understood in Taiwan region. The purpose of this paper was to assess the impacts of potential control strategies for reducing the risk for TB infection among elderly in senior care facilities and to provide the suggestions for sound TB infection control measures that should be implemented in all senior care facilities with aged people suspected of having infectious TB. We proposed an integrated-level mathematical model, incorporating the TB transmission dynamics, the Wells–Riley mathematical equation, and the competing-risks model to quantify the potential spread of TB bacilli in senior care facilities. We found that individuals living in hospital-based nursing homes had much higher exposure to TB than those in long-term and domiciliary care facilities. We showed that the proposed combinations of engineering control measures (e.g., ventilation and ultraviolet germicidal irradiation) with personal protection (e.g., surgical mask) guarantee the provision of a reliable control strategy to decrease the transmission potential and spread rate of TB bacilli aerosols in senior care facilities in that the efficacies range from 45 to 90%. The introduction of appropriate TB transmission control measures may decrease TB annual incidence in senior care facilities by as much as 76–90% of tuberculin skin test (TST) conversion. Our study implicated that sound TB infection control measures, including diagnosis and prompt treatment of infectious cases should be prioritized.
Highlights
► The potential spread of TB bacilli in senior care centers can be modeled. ► Engineering with personal interventions guarantee a reliable TB control strategy. ► 76–90% control efficacies can be achieved by proper TB control measures. ► TB pathogen and human host in indoor environments can be mechanistically understood.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Large eddy simulation (LES) of the airflows around various types of block arrays was performed to estimate the pedestrian wind environment. Five types of uniform staggered block arrays with different aspect ratios and an array with a nonuniform height were selected for the simulations. The simulation accuracy was validated by comparing the drag coefficient and wind profiles with those of previous work. The characteristics of the spatially averaged mean wind profiles of the arrays were analyzed on the basis of the calculation results. This study reveals that the frontal area ratio, which is the product of the plan area ratio and building aspect ratio, is the most important parameter in estimating the pedestrian wind environment. In addition, a simple exponential equation was derived for predicting the pedestrian wind speed as a function of the frontal area ratio, which is applicable to various building aspect ratios and amounts of height variability.
Highlights
► Wind profiles within urban canopy were investigated based on large eddy simulation. ► Relationship between building geometry and pedestrian wind speed is disclosed. ► Pedestrian wind speed can be expressed as a simple power law function of building frontal area ratio.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
This paper presents the evaluation of zinc and titanium nano-oxide silane/siloxane emulsions and their resistance to biofouling by algal colonisation. A culture streaming study was conducted to evaluate each treatment using mortar samples. Characterisation of the treatments included assessment of the porosity, surface roughness, sorptivity, hydrophobicity, treatment depth and visual alteration. The results showed that nanoparticulate incorporation did not adversely alter treatment penetration. Nanoparticulate treatments improved water repellence significantly while effectively conserving the morphology of the substrate. Treatments had negligible impact on visual aesthetics of the substrate making them ideal for future retrofit and heritage schemes. It was concluded that the reduced bioreceptivity observed primarily stemmed from the nanoparticulates ability to photocatalytically breakdown contaminants.
Highlights
► TiO2 and ZnO nano-particulate enhanced water repellent facade treatments. ► Algae culture streaming study assessed biofouling of mortar. ► Bioreceptivity mechanisms assessed independently. ► Improved water beading and sorptivity. ► <0.1%wt nano-particulate incorporation achieved photo-induced sanitisation.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Adaptive thermal comfort standards hold the potential for energy savings and greenhouse gas emission reductions in naturally ventilated buildings. The potential for energy savings relies on the fact that applying adaptive standards, indoor comfort temperature is shifted up on warmer days and shifted down in colder ones. In order to determine the correct comfort temperature inside, two variables need to be known in advan The clothing insulation level and the metabolic activity of the inhabitants. Using an adult population, it was observed that the clothing insulation level can be calculated based on recent thermal memory and weather prediction. The field study was carried out with 732 individuals for one year. All individuals performed the same task. In these circumstances, the clothing insulation level revealed to be a key issue. The clothing insulation level of the population was determined by the clo-checklist method and showed significant variation along the time period, with standard deviation representing about 23% of the mean clo (1 clo = 0.155 m2 K W−1). Results showed that the clothing insulation level worn inside has the most significant relationship to the previous day’s average outside temperature (Tday.x−1: R2 = 88%) followed by the maximum outside temperature during that day (maxTday.x: R2 = 71%).
Highlights
► Estimation of the clothing insulation level using only two temperatures. ► Influence of clothing insulation level on adaptive thermal comfort calculations. ► Calculation of adaptive thermal comfort temperature using two temperatures. ► Adaptive thermal comfort optimal temperature consistent with previous works. ► Simple methodology in influenced by every day actions like garment choices.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
The construction industry including its support industries is one of the highest consumers of natural resources. In the act of consumption of natural resources during construction processes, embodied energy and greenhouse gases are emitted which have adverse effects on the natural environment. Thus, recent studies have revealed a significant interest in the quantification of embodied energy and greenhouse gases in construction processes. Unfortunately, current interpretations and quantification procedures of embodied energy and greenhouse gases are quite unclear. More also, while greenhouse gas and embodied energy quantification models are so disaggregated, studies reveal their existence in isolation without any links to other important environmental/construction management variables such as waste, time and cost. The objectives of this study are to identify the gaps in the current computation models, to reveal the relationships between the identified models and to propose a framework towards developing an integrated model for measuring embodied energy, greenhouse gases, construction waste, time and cost. The contributions of this study are three-fold. Firstly, the identification of the different models and variables, such that they can be used in computations, that can lead to consistent and comparable results. Secondly, investigate the relationships amongst embodied energy, greenhouse gases, construction waste, cost and time variables, that can facilitate the quantification process and hence potentially facilitate the engagement into low carbon building design by construction professionals. Lastly, lay the foundation for further research especially with regards to the integration of the different models and variables so that they can be measured simultaneously.
Highlights
► Estimation models for Embodied Energy/CO2, Construction Waste, Time and Cost. ► Existence of Embodied Energy/CO2, Waste, Time and Cost Models as Isolated Models. ► Towards the Integration of Embodied Energy/CO2, Waste, Time and Cost Models.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
Thermal comfort, influenced by thermal sensation is an important building performance indicator. In this study we discuss the use of a thermophysiological model in the built environment to assess thermal sensation. In the context of this work, the use of CFD to simulate the thermal environmental conditions around a human is analyzed. Experimental data from two independent studies, covering both genders, are used to validate three different, currently available, thermal sensation models: (1) the Predicted Mean Vote index (PMV), (2) the UC Berkeley thermal sensation model and (3) the EN-ISO 14505 standard. Use of such a model is required to link physiological responses to thermal sensation. In this study they have been evaluated for two different steady-state non-uniform thermal environments. The results confirm that the PMV is not capable of predicting whole body thermal sensation when local effects (local skin temperatures and thermal sensation) have a significant influence. The results furthermore indicate that the use of a thermophysiological model (ThermoSEM) in combination with the UC Berkeley model or EN-ISO 14505 standard seems to be promising regarding the prediction of thermal sensation of local body parts and overall thermal sensation under steady-state non-uniform environments. The advantage of using a thermophysiological model in combination with a thermal sensation model is that thermal comfort can be assessed on a more individualized level under complex, daily encountered, thermal environments where local effects play an important role. However, both thermal sensation models need more research before they can be used in daily building design practice.
Graphical abstract
Highlights
► Thermal comfort is an important building performance indicator. ► ThermoSEM is able to predict physiological responses for different subpopulations. ► Local skin temperatures and sensation can influence whole-body thermal sensation. ► The ISO 14505 method seems to be very promising to predict the thermal sensation. ► More research is needed on the use of the equivalent temperatures and terminology.
January 2013 Publication year: 2013 Source:Building and Environment, Volume 59
The inhalation of micron particles by a manikin standing in a ventilated indoor environment was numerically investigated using Computational Fluid Dynamics (CFD). Computations were conducted with various combinations of the free stream velocity (0.05–0.25 m/s representing typical indoor wind speeds.), occupant orientation relative to the free stream (back-to-the-wind or facing-the-wind) and heat transfer (isothermal or thermal flow). It was found that the body heat has a significant impact on the airflow field in the vicinity of the manikin by causing an upwards airflow on the downstream side of the manikin. It was also found that the effect of body heat on particle inhalation depends on the manikin orientation relative to the free stream. When the manikin is facing-the-wind, body heat has a little effect on particle inhalation and can be neglected. However for a back-to-the-wind orientation, the situation is much more complicated as the source height of inhaled particles depends on the speed of free stream. When the wind speed is low (0.05 m/s), the critical area is located near the floor level. The central height of the critical area then increases with increasing free stream speed until it reaches the nose height when the wind speed rises up to 0.25 m/s. This indicates that the body heat is an important consideration when investigating contaminant inhalation by human occupants in low-speed (typically less than 0.2 m/s) indoor environment.
Highlights
► CFD technique presented to integrate gas-particle two-phase flows and heat transfer. ► Body heat causes a significant uprising airflow on the downstream side of the human body. ► The importance of body heat on particle inhalation is associated with the occupant orientation relative to the free stream. ► Body heat has a significant effect on particle inhalation when the occupant is back to the wind.
February 2013 Publication year: 2013 Source:Building and Environment, Volume 60
The air exchange in rainscreen walls is expected to provide ventilation drying if excess moisture is absorbed in the wall construction. In an earlier paper, we presented a cavity airflow model and measurement based estimations of air change rates (ACH) in south-facing experimental walls. Here, focus is on the ventilation drying process and its practical implications. ACH in the experimental walls were calculated and converted into drying rates at different stages in the drying process. Furthermore, changes in the drying rates due to changes in the cavity design and in the outdoor climate were investigated. The significance of the drying rates was demonstrated in a case study.Findings showed that the cavity design is of major importance for the drying rate if the material adjacent to the cavity is wet over its entire extension. For such extreme cases, a light façade colour, vented horizontal battens and, in particular, a small cavity depth, are adverse factors for the drying rate. As the drying process proceeds and the moisture transport from the material to the cavity air becomes dependent on vapour diffusion, the drying rates for different cavity designs tend to be evened out. If the resistance to vapour flow in the material reaches high levels, a favourable outdoor climate is significantly more important than the cavity design to promote drying. Also for the case where the material adjacent to the cavity initially is only locally wet, findings showed that the cavity design is of minor importance for the drying time.
Highlights
► We studied relations between cavity design, air change rate and ventilation drying. ► Calculated air change rates compared well with estimations based on experiments. ► Ventilation drying rates were calculated at different stages in the drying process. ► The significane of the ventilation drying rates was demonstrated in a case study. ► A small cavity depth (<10 mm) prolongs the ventilation drying process significantly.
February 2013 Publication year: 2013 Source:Building and Environment, Volume 60
Passive solar design in the Pacific Northwest relies greatly on traditions established elsewhere, resisting adoption of distinct regional practices despite growing evidence of their value. To promote progress toward climate-responsive design in the cloudy, rainy Cascadian corridor, and to gain insight into often-troubled passive solar performance in the region, energy transfer mechanisms underlying the measured performance of four Oregon sunspaces were investigated using EnergyPlus building models. Air, mass, globe, and soil temperatures, as well as relative humidity and incident solar radiation, were recorded at 10-min intervals in each sunspace from January through June, 2011; models incorporated geometric, material, occupancy, equipment, tree shading, and soil parameters relevant to energy gain and loss. Models were then validated by comparison with air and mass temperature data: all predicted 84–93% of measurement variability. Output showed that over half of all energy entering each sunspace originated as diffuse solar radiation, and that 60–70% of the total was transmitted through shallow-pitched roof glazing, in a pattern contrary to established belief. Similarly, much stored energy was lost through central rather than perimeter floor mass. Orientation exerted a minor effect on performance compared to other factors, particularly tree shading, while solar gain exceeded predictions of long-accepted methods by factors of two to three. Together, these results show that substantial revision of deep-rooted ideas and expectations will be needed to achieve high-performance passive solar heating in the Pacific Northwest.
Graphical abstract
Highlights
► Four sunspaces were monitored January–June 2011 and modeled in EnergyPlus. ► Low-pitched roof glazing admitted 60–70% of all solar gains, in large part as diffuse radiation. ► Floor thermal mass lost heat readily to moist soils, mainly through central (not perimeter) areas. ► Solar resources were ∼2× greater, and much less affected by azimuth, than Balcomb’s work predicts. ► Result: passive solar design rules based on low sun angles and dry soils are invalid in the Pacific NW.
February 2013 Publication year: 2013 Source:Building and Environment, Volume 60
Precise and efficient control strategies of heating, ventilation, and air conditioning (HVAC) systems need detailed and dynamic indoor environment information, which is hardly acquired satisfying realtime and precision requirements simultaneously. In this study, a fast simulation method based on existing proper orthogonal decomposition (POD) is proposed for dynamic modelling and control of indoor temperature distributions. To meet the realtime and precision requirements at the same time, an offline-online scheme is applied. In the offline stage, the finite volume method (FVM) is used for spatial and temporal discretizations of the indoor temperature distributions. The obtained ordinary differential equations (ODEs) are further order-reduced by POD (Karhunen-Loève)/Galerkin techniques. Snapshot method is used for the reduced-order basis construction. In the online stage, the model predictive control (MPC) strategy is used for the purpose of reference trajectory tracking, within which the proposed POD model is embedded to realtime estimate spacial temperature variation. Both transient and steady performances of the reduced-order model are compared with those of CFD-based simulation. A boundary control test is finally given, which demonstrates the applicability of the technique.
Highlights
► POD method is proposed for dynamic modelling of indoor temperature distributions. ► Transient/steady performances of the POD model are compared with CFD simulations. ► The POD model is embedded in a control scheme for high-precision control purpose. ► A boundary control test demonstrates the applicability of the proposed technique.
February 2013 Publication year: 2013 Source:Building and Environment, Volume 60
Knowledge of the pressure distribution on building walls is important for the evaluation of wind loads and natural ventilation. Wind-induced pressure distributions are influenced by a wide range of factors including approach-flow conditions, urban surroundings and building geometry. Computational Fluid Dynamics (CFD) can be a valuable tool for determining mean wind pressure coefficients on building facades. However, while many CFD studies of mean wind pressure on buildings have been performed in the past, the vast majority of these studies focused on simple building geometries without facade details such as balconies. These details however can drastically influence the flow pattern and the overall pressure distribution on the facade. This paper presents a systematic evaluation of 3D steady Reynolds-Averaged Navier–Stokes (RANS) CFD for predicting mean wind pressure distributions on windward and leeward surfaces of a medium-rise building with and without balconies. The evaluation is based on a grid-sensitivity analysis and on validation with wind-tunnel measurements. It is shown that building balconies can lead to very strong changes in wind pressure distribution, because they introduce multiple areas of flow separation and recirculation across the facade. The results show that steady RANS, in spite of its limitations, can accurately reproduce the mean wind pressure distribution across the windward facade of the building. The average deviations from the wind-tunnel measurements are 12% and 10% for the building with and without balconies, respectively. In addition, also the important impact of the reference static pressure and the turbulence model are demonstrated.
Graphical abstract
Highlights
► Steady 3D RANS CFD simulations for wind pressures on buildings with balconies. ► Detailed grid-sensitivity analysis and validation with wind tunnel measurements. ► Building balconies strongly influence mean wind pressures at building facades. ► Local differences in mean wind pressure coefficients: increase of 0.6, decrease of 0.7. ► 3D steady RANS gives very accurate results: 10–15% accuracy at windward facade.
February 2013 Publication year: 2013 Source:Building and Environment, Volume 60
This paper studies the performance of an integrated ceiling diffuser and personalized ventilator coaxial nozzle system to localize the air conditioning and fresh air needs around the occupants. The coaxial nozzle minimizes air entrainment between the fresh air stream and the room air and allows effective delivery of clean air. A detailed 3D CFD model is coupled to a bioheat model to improve prediction of the microenvironment conditions around the human and the associated local and overall thermal comfort. Subjective assessments were carried out with 10 human participants who were given the chance to undergo three different experimental runs individually and cast their votes about thermal comfort. The 30 samples obtained experimentally were within ±20% of the predicted numerical values especially for the upper body parts. Extensive simulations were performed to assess the effect of nozzle supply temperature and flow rate on the performance of the cooling system and on occupant comfort. The localized air conditioning system reduced the energy consumption by up to 34% when compared with conventional mixing systems providing the same level of thermal comfort.
Highlights
► A low-mixing ceiling-mounted nozzle integrated with a diffuser was modeled. ► The CFD model was coupled with a bioheat model predicting human thermal response. ► No local thermal draft was reported by the subjects. ► Thermal comfort conditions equivalent to those obtained with mixing systems were observed. ► The system provided energy savings up to 34% when compared to mixing systems.
February 2013 Publication year: 2013 Source:Building and Environment, Volume 60
Our previous study [1] demonstrated that for a thermal manikin in a horizontal airflow, its orientation relative to the free stream has a significant effect on the characteristics of particle transport and inhalation. Based on this conclusion, the previous research [1] was extended and the effect of leg posture (e.g. combined legs and divided legs) on particle inhalation in horizontal free stream was investigated using Computational Fluid Dynamics (CFD) in this study. The numerical results agreed well the experimental data and empirical correlations in the literature. It was revealed that for an occupant standing with its back towards the horizontal airflow, a little change in the leg posture can lead to an obvious variation in the source location of inhaled particles. It was also found that different leg postures have different environment sensitivity since when the manikin legs are divided, the central height of the critical area does not obviously change with increasing wind speed, however, this central height increases significantly with the wind speed when the legs are combined.
Highlights
► CFD technique to integrate gas-particle flow and heat transfer. ► Leg posture has a significant effect on particle transport. ► Different leg posture has different environment sensitivity. ► The open legs allow higher particle inhalation.
