Middle Floor Research Articles

LCV Vehicle in-cab noise prediction and reduction using SEA based simulation approach

With increase in consumer demand vehicle OEMs are developing quieter vehicles at a design stage using acoustic simulation tools to reduce development cycle times avoiding costly proto builds and test iterations. Present work describes application of statistical energy analysis (SEA) simulation approach for in cab noise prediction and noise reduction through sound package optimization for LCV vehicle. In first step complete vehicle in-cab SEA model is prepared with baseline sound package concept. It consists of comprehensive definition of structural panels, interior and exterior cavities. Noise control treatment is modelled as multi-layer poro-elastic materials. Airborne noise excitations for sources engine, transmission, intake and exhaust muffler are applied. Source strengths for above sources were derived from dyno-coupled powertrain noise tests in the anechoic chamber. Load case of rated speed was considered neglecting tire and wind noise during simulation. Contribution analysis was carried out to find out sensitivity of different panels on interior noise at various frequencies. It was observed that bottom middle floor panel and rear glass panel were major noise contributors. Noise mitigation was carried out by optimizing floor panel sound package and intake air filter within given space constraints. These modifications resulted in overall 2 dB in-cab noise reduction

Air-conditioning anthropogenic heat in high-density residential areas: Spatial patterns and impacts

The overheated urban environment has drastically increased air-conditioning (AC) usage, which induces extensive heat emissions from outdoor units. This phenomenon is more adverse in high-density residential areas as the air-conditioning anthropogenic heat (ACAH) would further cause localized heat accumulation in canyons, negatively impacting AC energy consumption and residents’ comfort. While previous research has explored the impact of ACAH on urban canyons, there is a lack of studies that systematically investigate the pattern, impacts, and mitigations of ACAH at a refined scale in high-density residential areas. This study aims to investigate the temperature distribution under ACAH and quantify its impact on cooling energy consumption and pedestrian thermal discomfort. High-density residential areas were categorized by different heights of buildings and directions of outdoor unit placement. Numerical simulations were conducted to study ambient temperature distribution. Results showed that the worst heat accumulation was at the windward position of the AC outdoor unit, and the outdoor temperature on the middle floor was 2.3 °C higher than that on the upper floor, resulting in a higher energy consumption of 6.3 W/m2. The worst case with taller windward buildings caused 55 % of the pedestrian areas to be more uncomfortable. Mitigation strategies were also proposed from multiple perspectives, including heat source optimization (e.g., cross-layout of AC outdoor units) and offering subsidies for AC electricity consumption gaps. The study provides a systematic research perspective on spatial heat accumulation patterns in high-density residential areas, which is instructive for mitigating urban warming and promoting sustainable urban development.

Dynamic analysis of the Xiaoyan Pagoda in China: Mechanisms for resisting rare earthquakes

The Xiaoyan Pagoda in Xi'an stands as a UNESCO World Cultural Heritage site, having endured severe damage from numerous powerful earthquakes without collapsing. To comprehensively understand its behavior during earthquakes, a Block Discrete Element (3DEC) analysis method was employed. The numerical model underwent scrutiny aligned with in-situ dynamic test results. The dynamic response of the pagoda was calculated separately while subjected to the influence of three seismic waves under two conditions: rigid foundation and considering soil-structure interaction (SSI), and the damage process was analyzed. The calculation results reveal that under conditions of a rigid foundation, the ancient pagoda experiences displacement increases suddenly of each floor and eventual collapse when subjected to an intensity of 8-degree (PGA=0.40 g) earthquake. However, when accounting for the constructive characteristics of the foundation soil and considering soil boundary effects, the pagoda of dynamic characteristics differ, resulting in a seismic response lower than that of the rigid foundation scenario. During a rare earthquake of intensity of 9-degree (PGA=0.62 g), observed block detachment occurs at the top floor and the pagoda eaves of the middle floor, aligning with historical patterns of damage seen in the Xiaoyan Pagoda. These research outcomes offer valuable insights, serving as a reference for enhancing the seismic resilience of the Xiaoyan Pagoda structure and predicting its earthquake collapse risks.

ЕНЕРГОСПОЖИВАННЯ ШКОЛИ В УМОВАХ НЕПОВНОЇ ЗАЙНЯТОСТІ ДЛЯ РІЗНИХ РЕЖИМІВ ОПАЛЕННЯ ПРИМІЩЕНЬ

The challenges facing the Ukrainian education system, particularly in light of demo-graphic changes and the impact of war, are examined in this research. It highlights the poten-tial for optimizing the operation modes of school buildings under conditions of partial occu-pancy to reduce energy consumption and ensure comfortable conditions for students. Energy modeling analysis using DesignBuilder software shows that the configuration of classrooms significantly impacts the energy efficiency of buildings. The best results for energy efficiency were achieved with rooms stacked on top of each other, outperforming the variant with three rooms on the middle floor by 22.3%, and mixed configurations by 8.5% and 16%. This efficiency is due to minimized contact with unheated premises and maximized solar heat gains. However, without appropriate building upgrades, the use of limited spaces may not provide adequate comfort conditions in colder periods. For the rooms studied (45-48m^2), the required heating device capacity to maintain comfortable conditions varies from 7.5 to 10.5 kW, depending on the level of insulation, which is 3-5 times more than the standard capacity for such spaces. Providing comfortable conditions without upgrading the heating system in cold periods is unfeasible, even with high levels of building insulation and a constant heating schedule. Therefore, implementing partial use of school buildings, despite their high potential for en-ergy savings, cannot satisfy student comfort needs without corresponding improvements. Future research could provide a foundation for developing comprehensive strategies for managing school spaces, considering variable building usage conditions and ensuring an optimal combination of energy efficiency, cost-effectiveness, and comfort for students and staff. The findings can be useful for school administrations, local educational authorities, and policymakers in education and energy efficiency. Further studies are suggested to explore the impact of internal wall insulation, increased heating device capacity, and heating uncondi-tioned rooms to a certain temperature level on energy efficiency and comfort conditions in occupied spaces.

Effects of different zoning thermostat controls on thermal comfort and cooling energy consumption in reading rooms of a library

This study assessed thermal comfort and energy consumption in indoor environments controlled by air or operative temperature. Reading rooms in a library were divided into several zones based on the distribution of operative temperature. Using air temperature of the inner zone in thermostat control yielded the lowest energy consumption but the poorest thermal comfort level. Conversely, using operative temperature of the least favorable exterior zone resulted in higher energy consumption and comfort levels. The suggested optimal control based on switching boundary temperature minimized energy consumption while satisfying the thermal comfort requirement. The switching boundary temperature range on the top floor is 0.7 °C lower than on the middle floor due to the influence of the roof. The thermostat control modes had similar effects on the east and west reading rooms. The switching boundary temperature ranges of north room was 2.0 °C higher than those of the south room. Zoning control using air temperature control in the inner zone and operative temperature control in the exterior zone was recommended as a much simple mode to keep thermal comfort with low energy use. This study provides insights about the use of operative temperature in zoning thermostat control and theoretical guidance for practical implementation.

Reconstruct the 3D load redistribution paths of framed structures subjected to local column failure and multi-floor fire

Considering the slabs in the global response of steel framed buildings in fires is important, as deflected floor slabs could redistribute the load to columns leading to column failure and even progressive collapses. Floor slab systems also experience tensile membrane action after deflection, which differs from the behaviour observed using 2D structural fire models. This paper focuses on unfolding the load redistribution mechanisms using 3D steel-concrete composite structure models, while multi-floor spreading fires and local failure of columns are considered. A framed structural model based on the Cardington building is designed and modelled, in which the composite slabs at different floors are simulated using the recently developed high-efficiency slab model to address the slab effect to the global load redistribution. Four hazard scenarios representing different states of the central column (i.e., fully protected, partially protected or failed) are given as the initiating local failure. The analyses with the 3D structural models show that the slabs can effectively pull up the failed column and the vertical loads are transferred to the adjacent columns. The worst scenario has been identified as the case experiencing column failure both at the upper floor and the lower floor, which leads to the middle floor without pulling action and causes significantly large deflection. This may be a scenario that local column failure triggers progressive collapse of a real building and should be prevented.

Optimizing window ventilation strategies for high-rise residential buildings with U-shaped lightwell: Simulating gaseous pollutant cross-room transmission

The lightwell structure widely used in high-rise residential buildings becomes a pathway for the cross-room transmission of gaseous pollutants. In order to devise effective strategies for window ventilation, it is necessary to conduct research on the transmission characteristics of pollutants in the lightwell. The unsteady-state characteristic of the temperature in natural conditions is represented using a sine function. The transmission of pollutants in the lightwell during the 24 h was simulated by computational fluid dynamics (CFD) employing the RNG k-ε turbulence model and continuous phase model. Three pollution sources were considered at three typical building heights: low floor (5 floors), middle floor (18 floors), and high floor (32 floors). Moreover, the window ventilation time was accurately determined by calculating the room's re-entry ratio near the pollution sources. The results show that the day (24 h) can be divided into three time periods based on the airflow pattern in the lightwell: the downward airflow time (17:00 to 2:30), the upward airflow time (5:00 to 15:00), and the transition time (2:30 to 5:00 and 15:00 to 17:00). During the transition time, pollutant is transmitted both horizontally and vertically, and all rooms around the pollution source are unsuitable for window ventilation.

Effect of Natural Ventilation on Thermal Performance of Different Residential Building Forms in the Hot-dry Climate of Jordan

This work presents a simulation study on the impact of natural ventilation on the thermal performance and thermal comfort of residential buildings of different forms in the hot-dry climate of Amman, the capital of Jordan. Three existing triple-storey residential buildings with different forms, i.e., rectangular, L-shape, and U-shape, are taken as case studies. Models with similar construction and dimensions of the buildings under investigation are designed using the OpenStudio plugin SketchUp software. Two rooms within these buildings have been considered for simulation with the aid of the EnergyPlus simulator for two cases: the basic case with no ventilation and the case with ventilation. The thermal parameters, including the air temperature, relative humidity, air speed, and mean radiant temperature of both rooms, have been extracted from the simulation. The thermal performance of these buildings is analyzed based on the indoor air temperature and mean radiant temperature, while the thermal performance is investigated via the ASHRAE-55 adaptive model. The results show that the rectangular-shaped building has the best thermal performance in unventilated conditions for the middle room on the middle floor (Room 1). In contrast, the U-shape shows better results for the west-northern room on the same floor (Room 2). On the other hand, introducing natural ventilation to the buildings reduces the indoor temperature and, subsequently, enhances the thermal performance where the buildings transform to be within the comfort zone most of the time, according to the ASHRAE-55 adaptive model. Generally, rectangular and U-shaped buildings show comparable thermal performance, while L-shaped buildings have relatively the worst performance.

Potential hazards and road-source apportionment of toxic trace metals in the dust from residential buildings in typical coal-utilization cities

Toxic trace metals in dust from residential buildings are closely related to human health, but the transmission route and impact degree of dust from coal utilization sources are still unclear. A total of 158 dust samples from different floors of 31 residential buildings in a typical coal-utilization city were collected and analyzed. Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) were used to analyze chemical speciation and sources of trace elements. Extremely high concentrations of Zn (14,308 mg/kg), Cu (553 mg/kg), Cr (319 mg/kg), Pb (1,208 mg/kg), As (30.8 mg/kg), and Cd (4.18 mg/kg) were found in the dust of residential buildings. Different trace elements tend to be enriched in different floor zones. The concentration of Zn was enriched in the low floor zone, while Cu and Pb were enriched in the middle floor zone, and Cd was enriched in the upper floor zone. The distribution of trace elements was found to be highly correlated between road dust and ground residential building dust, indicating that the input from road dust was the primary factor. Principal component analysis (PCA) combined with particle morphology and mineralogy study demonstrated that coal combustion, road and coal mining dust, and tire wear particles were likely sources of trace elements in dust. Risk assessments showed that As, Pb, and Cr in some samples were found to be harmful to children, particularly in high toxic forms of As (III) and PbO. This study provides systematic evidence for the transmission route and risk assessment of toxic trace metals in dust from residential buildings in coal-utilization cities.

Vibration Reduction in Passenger Vehicle by Optimization of Propeller Shaft Design

In Passenger segments, vehicles floor vibration is one of the major cause which leads to discomfort for passengers. There are several locations for vibration, one of the location is Floor of the bus where passengers will feel the vibration directly while sitting on the seats and while standing on the Gangways. So acceleration levels in passenger segment should be as per AIS 153 standard. The objective of this paper is, of all the available causes for vibration, we will discuss about the middle floor vibrations raised by Propeller shaft and how to mitigate the problem by various focused design proposals on Propeller shaft. Here, we will be reviewing the Bus segment which has a Double Piece Propeller shaft design configuration.

Anthropometric aspects used to treat fractures of the naso-orbito-ethmoido-maxillary (NOEM) complex in cases of facial trauma

Abstract BACKGROUND. Fractures of the naso-orbito-ethmoido-maxillary (NOEM) complex are frequently acquired post-traumatic lesions, with both aesthetic and functional consequences, if the diagnosis is not promptly established and the surgical correction is delayed. OBJECTIVES. This study was conducted in order to facilitate the diagnosis of NOEM complex fractures by using anthropometric measures. The aim was to obtain normal mean values of the evaluated parameters from a lot of healthy volunteers. MATERIAL AND METHODS. The measurements were conducted on patient-specific three-dimensional models obtained from processing the CT scan images and building further stereolithographic models. 64 Caucasian patients were enrolled, with ages between 19 and 93 years, both female and male volunteers, without previous surgical history of the middle floor of the face. Measurements were performed between certain craniometric points (Nasion, Dacryon, Infraorbital foramen, Rhinion and Frontomalare orbitale) and a database was created. RESULTS. Although some expected variation arised, we have obtained normal-considered intervals for each of the defined and measured segments between the mentioned craniometric points. We find these measurements useful especially for elaborating a presurgical plan for the best outcome. CONCLUSION. Simple measurements could orient a fast diagnosis, could help establish a surgical plan, an optimal surgical timing by combining clinical and imaging data.

The Coal Pillar Width Effect of Principal Stress Deflection and Plastic Zone Form of Surrounding Rock Roadway in Deep Excavation

In order to explore the influence of coal pillar width on the principal stress deflection and plastic zone form of surrounding rock in deep roadway excavation, taking 11030 working face transportation roadway of Zhaogu No. 2 Coal Mine as engineering background, theoretical analysis, numerical simulation, and field detection were used to study the effect of coal pillar width on principal stress deflection and plastic zone form and field detection and verification of plastic zone form of surrounding rock in 11030 transportation roadway. The results show that the maximum principal stress is deflected in the vertical direction, which in roadway surrounding rock excavation. The coal pillar width effect of principal stress deflection on both sides of roadway roof and floor and inside coal pillar are more obvious than that of middle roof and floor, coal pillar edge and coal wall position. The deflection of the principal stress affects the morphological distribution of the plastic zone of the surrounding rock, which led to the width effect of coal pillar in roof, and two sides plastic zone are more obvious than that in floor. The principal stress deflection of roadway surrounding rock is highly consistent with the maximum damage depth of plastic zone, and at the same time, the drilling peep results of surrounding rock are basically consistent with the form characteristics of plastic zone in numerical simulation. On this basis, the surrounding rock reinforcement support scheme of 11030 working face transportation roadway was proposed.

고층건축물의 높이에 따른 대류열전달률이 실내표면결로에 미치는 영향에 관한 이론적 연구

Although the temperature coefficient between outdoor air temperature and indoor air temperature is used to determine whether condensation occurs, it is reasonable to predict surface condensation using the surface temperature difference between outdoor and indoor. This study is conducted to determine whether condensation occurs by not using the air temperature difference between indoor and outdoor (the existing methods) but by applying the surface temperature difference between indoor and outdoor surfaces. The outdoor surface temperature is affected by air velocity on the building height, thus the convection heat transfer coefficient is different depending on the building height. The indoor surface temperature distribution is 21.4℃～21.5℃ when the existing equation is applied. But by applying the proposed equation, the indoor surface temperature distribution for the lower floor is 13.0～17.8℃, for the middle floor is 12.3℃～ 17.1℃, and for the top floor is 12.0℃～16.8℃. As the indoor surface temperature can be lower than indoor air dew point temperature, surface condensation is possible.

Psychological and Physiological Responses to Different Views through a Window in Apartment Complexes

Background and objective With increasing land use intensity in urban areas, apartment buildings have been recognized as a typical type of urban residence. In this study, the impacts of different views through a window on health-related responses were investigated using psychological and physiological parameters. Methods Photos of three different types of views taken on low (2–12 m), middle (28–35 m), and high (over 54 m) floors of dense apartment building areas were used as visual stimuli. Twenty-two healthy adults participated in the indoor experiment. Semantic differential methods and profile of mood states were used as psychological tools. Autonomic nervous activity was evaluated using blood pressures, pulse rate and heart rate variability (HRV). Results Analytic data showed different characteristics of psychological and physiological outcomes in three different apartment views. In the analysis of psychological parameters, significantly negative responses to the views on middle floors were found in the subscales of tension-anxiety and anger-hostility, compared to low floors. Significantly positive scores in the subscale of vigor were found on low floors with abundance of vegetation and high floors with a view of the sky. A significantly increased value of HF was found on low floors (2,294.96 ± 169.79), compared to the middle(1,553.45 ± 84.66) and high (1,523.02 ± 70.49) floors. Despite the high scores in openness and vigor, high floor views showed significantly higher LF/HF values (1.83 ± 0.09), the indicator of the sympathetic nervous system, than low (1.30 ± 0.07) and middle floor views (1.34 ± 0.06), which might be related to the unconscious fear of heights. Conclusion Views from different heights in an apartment building can affect the psychological states of residents. Green space through the window may have a positive health outcome by reducing physiological stress.

IMPROVING ENERGY EFFICIENCY OF MULTI-FAMILY APARTMENT BUILDINGS CASE OF JORDAN

Saving energy is a high priority in developing countries and several energy-efficient initiatives are being introduced for that purpose. The residential sector is responsible for a big part of the world's energy usage; most of this energy is used in heating, cooling, and artificial ventilation systems. The residential sector in Amman consumes more than 21% of the annual energy consumption, meanwhile multi-family residential apartments occupy more than 60% of that sector. With a view on developing energy-efficient structures, this study provides an overview of building design criteria that can reduce the energy demand for heating and cooling of multi-family apartment residential buildings. These criteria are based on the adoption of suitable parameters for the orientation of the building, shape, envelope system, use of insulation materials, passive heating and cooling mechanisms, setting of cooling and heating thermostat, lighting, and window's ratio and glazing. This experiment measures the effect of these criteria on overall energy demand that reviewed and recommended the best design choices. This is beneficial for professionals in the design phase of energy-efficient multi-family residential buildings and decisions makers. The methodology that is used in the study was represented in field observation and surveys, besides, to use design-builder as a simulation tool to test the assumptions and the design strategies, the results indicate that a 6cm polystyrene insulated walls and roof for a north/west middle floor apartment and WWR ranges from 25 to 30% of double bronze glass will affect greatly in the energy demand.Keywords: energy-efficiency, multi-family residential apartment, design strategiesJEL Classification: Q2DOI: https://doi.org/10.32479/ijeep.11394

Pumping ventilation of corner and single sided rooms with two openings

Corner rooms with two or more open windows in perpendicular facades can be naturally ventilated in cross-ventilation or pumping ventilation. These two airflow regimes also occur in rooms with two openings in the same façade, in the form of single sided pumping or cross sided ventilation. This paper presents an experimental and numerical simulation study of the scale and occurrence of these two flow regimes for rooms in a rectangular building exposed to wind. Flow visualization and tracer gas measurement of effective airflow were performed in an atmospheric boundary layer wind tunnel using a rectangular model of a three-story building (1/20 scale) with a ventilated middle floor. Experimental results show that pumping ventilation occurs when the wind is perpendicular to the façade (single sided rooms) or aligned with the building corner (corner rooms). In addition to these two perfectly aligned wind directions, pumping also occurs for a range of incoming wind angles: ±19° for single sided; and ±9° for corner rooms. As a result, for isolated rectangular buildings that have, at least, one single sided and two corner rooms in each facade, pumping ventilation can potentially occur in two or more rooms for 62 % of incoming wind directions. To investigate the transition between steady cross-ventilation and unsteady pumping ventilation, three-dimensional computational fluid dynamics large eddy simulations were performed to obtain wind generated pressures in the ventilation openings. Results show that the transition from cross-ventilation to pumping occurs when the steady pressure becomes smaller than the unsteady component. These results are used to develop a pressure based simplified model for corner ventilation that can predict effective airflow from external wind generated pressures with an average error below 10.2 %.

Seismic responses of the densely distributed caves of the Mogao Grottoes in China

Some of the largest and best-preserved Buddhist art treasure houses in the world, namely the Mogao Grottoes, are located at the northwest edge of the region of the Qinghai-Tibet plateau and are adjacent to the Altun and Qilian mountains, where the geotectonic activity is intense and large earthquakes have occurred. Future earthquakes are one of the major threats to the caves of the Mogao Grottoes; therefore, it is important that their dynamic performance is studied when an earthquake occurs. To understand the dynamic performance of the densely distributed caves under the effect of earthquakes, as well as the long-term stability of the Mogao Grottoes, the stress distribution, deformation characteristics, and peak-acceleration amplification factor were analysed under rare-earthquake conditions using a finite-difference element. The numerical study revealed that the most dangerous state of the caves is the initial time when an earthquake occurs. The obvious tensile stress concentration appeared at the top and the bottom of the caves of the middle floor; the main damage was caused by the shear failure towards the direction of the free face and not by the tensile failure. A large permanent horizontal displacement of the caves occurred after an earthquake, mostly at the densely distributed caves of the middle floor. The acceleration amplification effect of the middle-floor caves was significant; the Fourier amplitudes of the acceleration (which were monitored in all caves) were significantly magnified at the frequencies of 3 ~ 4 Hz and 7 ~ 9 Hz, whereas the Fourier amplitudes of the acceleration which were monitored in the middle-floor caves were almost amplified within the entire frequency range. Although the maximum stress was within the allowed limit and no tensile failure occurred, great permanent inhomogeneous horizontal displacements and large accelerations could have a negative effect on the stability of caves and the preservation of wall paintings. Moreover, it was assumed that the calculation results could serve as a type of guidance and as advice on the preventive protection of the Mogao Grottoes.

Theoretical Study of Energy Saving Through Redesign of Water Distribution Arrangement in a Medium-Rise Residential Building

Abstract The development of medium-rise buildings for the residence is the basic necessity to accommodate the growing population of countries like India where the residential land per capita is very small. Moreover, because of the energy shortage, energy-efficient development is the primary objective in the present scenario. With the efforts of reducing energy consumption in the medium-rise buildings, redesign of the water distribution system has been proposed in this study. In this proposed arrangement, two water pumps are placed at two different elevations, namely, ground and middle levels of the building. The first one at the ground level supplies water first to the middle floor flats and the second one at the intermediate level does for the middle to the top floor flats. Various building heights and pumps are studied theoretically and the analysis of the results shows that about 20% of the total pump energy can be saved by changing the way of water distribution in the residential buildings. Yet further energy-saving potential is available through the selection of better efficiency pumps. Moreover, reduction in pressure of the water at the lower floor flats is an additional advantage of the proposed arrangement.

Glandular and Cystic Bladder Cystitis: Case Report and Review of the Literature

Glandular-cystic bladder cystitis is a rare, benign non-tumor condition, preferentially located on the area of the bladder trigone and can simulate a malignant tumor. It is a benign reactive metaplasia of the bladder submucosa, characterized by hyperplasia of the islets of Von Brunn and cystic. It is classified among reactive epithelial anomalies of the urothelium, such as islet hyperplasia of Von Brünn, cystitis, glandular cystitis, nephrogenic metaplasia and epidermoid metaplasia. It presents a clinical diagnostic challenge having the expression of a simple recurrent cystitis and misleading the radiological diagnosis evoking a malignant tumor of the bladder. Its certainty diagnosis is histological. We report the case of a 38-year-old young man who consulted for recurrent cystitis. The CT scan showed a vegetative tissue structure of the middle and left medial vesical floor, sawtooth 3 cm long axis suspecting a tumor of the bladder. The patient underwent transurethral resection of the bladder lesion. The histological and immunohistochemical examination concluded with glandular and cystic cystitis (minor form). In the light of this observation, we will discuss the diagnostic difficulties, the pathophysiological mechanisms, the radiological aspects, the anatomopathological, therapeutic features and the prognosis of this rare condition. The literature regarding this entity has been reviewed and the differential diagnosis was discussed.

Experimental and numerical investigation of pumping ventilation on the leeward side of a cubic building

Unstable interaction between shear layers that form in the wake of an isolated building exposed to wind can drive natural pumping ventilation in windward and leeward facing rooms with two or more horizontally separated openings. This paper presents an experimental and numerical study of pumping ventilation in a three-story cubic building with two leeward openings in its middle floor. Reduced-scaled measurements were performed in the University of Gävle atmospheric-boundary-layer wind tunnel. The ventilation mechanism was investigated using smoke visualization, hot wire anemometry and particle image velocimetry. Effective ventilation rates were obtained using a tracer gas decay method.Experimental results confirmed that pumping ventilation is a 3D oscillatory unstable phenomenon with periodic behavior over several oscillation cycles. Measured flowrates show a linear relation between the effective ventilation rate and window separation. The numerical simulations used two turbulence modeling approaches: unsteady Reynolds-averaged Navier-Stokes (URANS) and large eddy simulation (LES). Both URANS and LES could predict vortex shedding frequency with an error below 5%. LES showed a good agreement with the measured ventilation rates, with an error below 10%, while URANS underestimated ventilation rates by at least 40%. The ventilation efficiency, obtained by LES, ranged between 0.60 and 0.75 (for the case with larger window separation). The results show that LES may be a suitable simulation approach for pumping ventilation. In contrast, URANS cannot simulate pumping ventilation.