Louver Angle Research Articles

Investigation on the performance of a solar multifunctional photovoltaic/thermal window combining photocatalytic oxidation technology

In response to the challenges of high energy consumption and poor indoor air quality, a novel solar multifunctional louver window has been proposed. This study developed a numerical model to examine the effects of environmental variables and louver angles on the thermal, electrical, and degradation performance of the system. Additionally, an exergy-based evaluative framework was introduced to account for the varying qualities of energy in assessing the performance of solar multifunctional windows. Finally, a comprehensive evaluation was conducted using this framework. The results demonstrate that the exergy efficiency of the solar multifunctional window can be maintained at 20 % or higher, even under reduced solar irradiation, delivering high-quality energy. Lower environmental temperatures and solar radiation intensities were found to negatively affect ventilation, thermal efficiency, and air purification capacity. The thermal, purification, and electrical efficiencies were influenced by the louver angle to varying extents. In terms of air purification, the window achieved the highest Clean Air Delivery Rate (CADR) at louver angles between 80° and 90°, thereby enhancing air purification performance.

Effect of trapezoidal louvered winglets on increased heat transfer and exergy in tubular heat exchanger

The effect of inserting a trapezoidal louvered winglet tape (TLWT) into a uniformly heat-fluxed tube on its thermal effectiveness was studied experimentally. The exergy and entropy analyses for turbulent flows, as well as frictional loss and thermal features, were highlighted as key aspects of the experimental finding for the Reynolds number which measured between about 4700 and 30,000. Because fixing baffles to the curved shape of tube wall presented a challenge, the baffles were consequently positioned on double surfaces of a flat tape. Six values of the louver angle (θ1 = 0°, 25°, 30°, 45°, 60°, and 90°) and three values of the relative pitch of winglet (PR = 1.0, 1.5, and 2.0) were employed in the arrangement of TLWTs, with the V-apex oriented upstream (V-up). Each of these had only a fixed height (BR = 0.25) and angle of attack (α = 30°). The winglets were utilized to induce streamwise vortices which can hinder the boundary layer formation, while the louvered openings were adopted to lessen pressure drop without significantly impacting the primary vortices. The experiment results disclosed that the smallest θ1 and PR produced the largest relative friction factor (fR) and NuR, which were about 13.57 and 4.04 times higher, while PR = 1 and θ1 = 45° provide the greatest TEF of about 2.27. The greatest exergy efficiency (ηEx) resulting from the TLWT was reached at θ1 = 0°, but the generation of entropy (S˙g′) dropped with lowering θ1 and Re. A further examination, however, showed that the best scenario with α = 60° and staggered arrays is more desirable since it yields the largest TEF of 2.45 at θ1 = 45° and PR = 1. For the range of parameters under consideration, the Nu and f correlations were additionally established.

Heat transfer analysis in a tube contained with louver-punched triangular baffles

The present research assesses the thermal effectiveness of a heat exchange tube incorporating louver-punched triangular baffle (LPTB) vortex generators under turbulent conditions. For Reynolds numbers between 4760 and 29,270, the heat transfer and flow behaviors in the consistent heat-fluxed tube equipped with LPTBs were studied numerically and experimentally. A single baffle height/blockage ratio (b/D = BR = 0.25) and relative baffle pitch (P/D = PR = 1) were used for both baffle attack angles, (α) 30° and 45°, along with three louver size ratios (e/b = LR = 0.24–0.56) as well as five louver angles (θ = 0°, 20°, 30°, 45°, 60°, and 90°). The results show that as the LR and θ values decrease, the Nusselt number (Nu) and friction factor (f) of the LPTB rise owing to the improved fluid mixing process generated by streamwise vortices with stronger turbulence kinetic energy. The LPTB with LR = 0 and θ = 0° provides the greatest f and Nu of about 22.18 and 5.1 times, respectively, although the one with LR = 0.24 and θ = 45° has the largest TEF of about 2.39 and 2.5 for the α = 30° and 45° LPTBs, respectively. Furthermore, an examination into the thermal and flow patterns was conducted through a three-dimensional computation; the validation of the numerical and experimental data yielded satisfactory results. Using measured data, the f and Nu correlations of the α = 30° and 45° LPTBs were additionally established.

Thermal effectiveness enhancement in heat exchange tube using louver-punched V-baffles

An efficient technique for reducing frictional loss by punching holes on the surface of vortex generators has been extensively researched, particularly in the form of louver-punched holes. This article describes an experimental and numerical examination of thermal effectiveness in a heat exchange tube with louvered baffle vortex generators (LBVG). As air was directed to the LBVG-inserted tube with a consistent heat flux, the flow was measured in a turbulent regime. The LBVGs were set at 30° attack angle (α) and mounted at regular intervals on a two-sided flat tape with one relative baffle height (b/D = RB = 0.25) and pitch (P/D= RP = 1) at the first step. The baffles had five different louver angles (θ = 0 ˗ 90°) and three different relative louver sizes (LR= e/b = 0.4, 0.56, and 0.72). The Nusselt number ratio (NuR), friction factor ratio (fR), and thermal effectiveness factor (TEF) were utilized to quantify the performance of LBVGs. The findings showed that LBVGs had much lower fR values than solid baffles (without holes), whereas NuR values decreased slightly. When θ and LR were reduced, the fR and NuR for LBVGs increased until they resembled those for solid baffles. Through numerical simulations using the realizable k-ε turbulent model based on the finite volume method, the flow and temperature fields of various cases were generated; their results were verified via analysis of the fluid flow patterns. The computational findings revealed that the jet flow from the louver hole could boost heat transfer, and TEF of LBVGs varied depending on the placement of the hole. According to the computations, the optimal TEF at RP = 0.75, LR = 0.4, and θ1 = 20° is roughly 2.64, and the hole should be placed toward the baffle ends rather than in the middle.

Numerical investigation of louver edges effect on the performances of louvered fin compact heat exchanger

The rectangular channel louvered-fin compact heat exchanger (LFCHE) is the most efficient type that has been served in a radiator. However, with this type of heat exchanger, the pressure drop rises by three to four times as the heat transfer increases, which results in decreasing performance. This research is aimed to numerically investigate the louver edges (vertical, inclined, and horizontal) effect on LFCHE performance at different louver angle (θ) with air inlet velocities ranging from 1 to 30 m/s. A total of twelve models are made and simulated. The result revealed that the horizontal edge decreases the pressure drop up to 24.2% with a 1.01% increase in outlet air temperature over the base model (inclined edge). Thus, louver edge has design which results in higher and lower effect on pressure drop and temperature change, respectively. The research investigated the effects of louver edges using different performance evaluation criteria. At 10 m/s (Relp = 972.33) the horizontal edge increases the volume goodness (jf) factor up to 21.49% over the base model. Similarly, the horizontal edged fins resulted in maximum increment of jf-factor by 22% and 25% as compared with inclined edge for louver angles θ of 24 ° (at low Relp) and 20 ° (at high Relp), respectively. Generally, the horizontally edged LFCHE is proven to have higher performance in cooling the coolant with a minimum air side pressure drop.

Orthogonal Pattern Louver Mixer for Two-Dimensional Air Mixing in HVAC Applications: Performance and Design Optimization

This article focuses on the investigation of the mixing and hydraulic performance of an orthogonal pattern louver mixer in a square duct. The investigation includes various configurations, including the following parameters: mixer spacing and louver pattern orientation for a pair of mixers, as well as louver angle and louver array size were for both a single and a pair of mixers. Additionally, operational parameters such as mixing length, total flow rate, and flow rate ratio between cold and warm air were considered. Experimental testing was conducted to assess the performance of the orthogonal pattern louver mixer across various parameter combinations. Additionally, a numerical model was developed to enhance understanding of the mixing pattern and flow behavior. Numerical results highlighted that the two-dimensional mixing flow, characterized by multiple vortices generated through the unique louver design, significantly contributed to rapid and robust mixing, effectively reducing maldistribution within a short mixing length. The performance of the orthogonal pattern louver mixer from the experimental results was compared to other mixer types, such as orifice type mixers and ASHRAE Standard 41.2-based “cheese grater” baseline louver mixers. The orthogonal pattern louver mixer was found to be outstanding, with a maximum mixing effectiveness of 88 % for a mixing length of 2.0 Dh. Although it caused a higher static pressure drop than the baseline louver mixers, it was still acceptable for industrial use. The findings indicate that the orthogonal pattern louver mixer is a promising option due to its simple design, easy fabrication, high mixing performance with low pressure drop, and two-dimensional mixing. The orthogonal pattern louver mixer was also less sensitive to flow rate and velocity maldistribution than orifice-type mixers. This article provides useful guidelines for designing and selecting the best mixer type for HVAC applications, considering factors such as cost-effectiveness, mixing performance, pressure drop, and sensitivity to flow rate and velocity maldistribution. In addition, the article offers valuable insights into the performance characteristics of single or dual-use orthogonal pattern louver mixers, as well as the importance of carefully selecting the louver angle and array size when configuring the mixer.

Impacts of horizontal and vertical louvers on the natural cross-ventilation performance of a generic building

Wind-based natural cross-ventilation is defined as a process in which fresh air is injected into a building via a high-pressure windward window and exhausts into the atmosphere through a low-pressure leeward window. There are several parameters that affect the natural ventilation performance, which should be considered in detail to reach the maximum air quality inside the buildings. In the present study, the effects of horizontal and vertical louvers on the wind-driven natural cross-ventilation performance of a generic building are assessed using computational fluid dynamics. In this regard, horizontal and vertical louvers with installation louver angles of 15°, 30°, and 45° are compared with each other and corresponding non-louver cases. Computations are carried out for three different free-wind speeds of 1, 2, and 3 m/s to show the impact of the external conditions on the natural ventilation of louvered cases. The obtained results revealed that under a low free-wind speed of 1 m/s, the minimum age of air and maximum air exchange efficiency occur for vertical louvers with an installation angle of 15°, while at moderate and high free-wind speeds of 2 and 3 m/s, the horizontal louvers with an installation angle of 15° provide the best condition for a generic building. Highlights Effects of horizontal and vertical louvers on the wind-driven cross-ventilation were studied. At a free-wind speed of 1 m/s, the minimum age of air and maximum air exchange efficiency occur for vertical louver with α = 15°. At U H = 2 and 3 m/s, horizontal louver with α = 15° provides the best condition for a generic building.

Evaluation of the impact of installation environment for a condensing unit of a split-type air conditioner in a plant room of Korean apartment dwellings

In many countries, split-type air conditioners have been widely used in residential buildings due to the high energy efficiency. It has been reported that optimal heat exchange conditions are necessary for the condensing unit of the air source air conditioner to perform at its rated level, particularly when installed in an apartment building's plant room. This study analyzes the impact of installation parameters of a condensing unit of a split-type air conditioner, such as the clearance distance from the rear surface of the condensing unit, the louver angle, and the use of insect screen or air-guide, on the cooling performance. The findings from the experiments and the correlations between parameters and input power presented in this paper would be useful in designing residential buildings with split-type air conditioners and air conditioner plant rooms for optimal cooling performance.

Correlations for forced convective heat transfer coefficients at the windward building façade with vertical louvers

Vertical louvers are a widely used external shading system to control natural lighting and solar heat gain for buildings. However, when installed on a building façade, they can disrupt the flow field around the façade and affect the external convective heat transfer process of building's exterior surfaces. To this end, this paper conducted CFD simulations to clarify the forced convective heat transfer patterns in a vertical louver-facade system based on the k-ω SST model with a detailed verification. The extended Newton's cooling equation is used to describe the heat exchange process between louvers, building façade, and air, which generates four heat transfer coefficients: hwa, hwb, hba, and hbw. Then the impacts of dimensionless temperature difference (θ), louver angle (φ), louver slat width (B), and installation distance (W) on the heat transfer coefficients are investigated. The results show that θ does not affect the average heat transfer coefficients. hwa reaches a minimum value and hba reaches a maximum value when φ = 75o. In addition, hwa increases by 55.3% and hba decreases by 21.9% as B increases from 0.3 m to 1 m. When W increases from 0.25 m to 1 m, hwa decreases by 5.6% and hba increases by 39.6%. The variation in the heat transfer coefficients (hwb and hbw) between the louvers and building façade is also explained. Finally, new correlations of paired heat transfer coefficients are established as a function of φ, B, W, and wind velocity (U10). The accuracy of these correlations is evaluated by comparing calculated values with simulated results.

Identifying external louver angle for residence opening to optimize the indoor environment for the composite climate of Delhi NCR

The essential part of any shading device is to intercept the solar radiation in such a manner that it allows enough daylight inside the building, while at the same time the indoor thermal comfort is upheld for all the seasons. Earlier studies proved that in comparison with internal shading devices, the external ones minimize the internal heat gain in an effective manner by blocking the radiation, before it reaches the fenestration glazing. However, fixed external shades are incapable of balancing the varying requirements of light and heat for different climatic conditions. Mainly, summer and winter in the composite climate demands adaptive shading solutions as per the changing season. The current study is an attempt to evolve appropriate external adaptive louver shades and recommend louver angles for different months, for a single space of a typical apartment building in Delhi NCR region. The recommended angles allow the occupants to make informed decisions by manually adjusting the louvers to improve the indoor environment. This study utilized ladybug and honeybee plugins for the purpose of simulation. The results show that the monthly adjustments of external adaptive shades enhance the indoor environment and save energy. The study developed, analysed and compared two different types of external adaptive louver shading systems such as EALS (External Adaptive Louver Screen) and EALA (External Adaptive Louver Awning) for better indoor environment and energy saving for west orientation.

Thermal performance and exergy analysis in a round tube with louvered trapezoidal winglets

An experiment was performed to investigate the influence of inserting a louver-punched trapezoidal-winglet (LPTW) into a uniform heat-fluxed tube in order to create a longitudinal vortex generator. This research aims to maximize both the thermal performance to increase energy savings, and the relative Nusselt number (NuR) at the optimal performance to reduce heat exchanger sizes. Therefore, the experimental result was emphasized on the thermal and pressure loss characteristics including entropy, and exergy analysis of the turbulent tube flow for Reynolds numbers (Re) that extended from 4760 to 29,280. The LPTWs were arranged by letting V-tip direct downstream with three attack angles (α = 30°, 45° and 60°) and five louver angles (θ1 = 0°, 25°, 30°, 45° and 90°), all at a single relative winglet pitch (PR = 1.0) and height (BR = 0.25). According to the findings, it revealed that the friction factor (f) and Nusselt number (Nu) of the LPTW at α= 60° and θ1 = 0° are, respectively, up to 29.1 and 5.5 times above those of the plain tube. With decreasing Re and θ1, the entropy generation (S˙′gen) was reduced to a lower value and the maximum exergy efficiency (ηEx) was obtained for the LPTW at α = 60° and θ1 = 0° The peak thermal performance around 2.5 together with NuR = 4.68 was found at a= 60°, θ1 = 45° and the lowest Re. However, the optimal condition at α= 60°, θ1 = 30° was preferable because it provides the greatest NuR = 5.04 at TEF = 2.47. Additionally, correlations for f and Nu were derived and presented for the range of parameters that were taken into consideration.

Effect of louvered curved-baffles on thermohydraulic performance in heat exchanger tube

The paper presents an experimental study of convection enhancement in a tube heat exchanger using louvered curved-baffle (LCB) vortex generator (VG). The heat transfer and pressure loss of air as a working fluid, flowing in an isothermal-fluxed tube were measured having Reynolds numbers (Re) between 4760 and 29,300. The LCB elements were arrayed on two tape sides in a V-shape with a 30° attack angle. At a fixed baffle height, the LCB had three axial pitch ratios (PR) from 0.5 to 1.5 and six louver angles (θ) from 0° to 90°. Thermal enhancement factor (TEF), Nusselt number (Nu), and friction factor (f) are often utilized to analyze the effect of VG geometrical variables on thermohydraulic performance. The measured results demonstrated that the LCB-inserted tube has a significantly larger Nu and f than a plain tube functioning alone, and that the Nu and f tend to rise when PR and θ decline. Using the LCB increases Nu and f by approximately 2.59–4.66 and 3.8–39.37 times, respectively. The maximal TEF is achieved for the LCB at PR = 1, θ = 45° and lower Re. Empirical correlations for Nu and f were evaluated and found to fit measured data well, with discrepancies by ± 9% and ±10%, respectively.

Effect of interior venetian blinds on natural convective heat exchange at a full-scale window glazing

• The setting of the louver enhances the convection heat transfer from the window. • The space of the louver from the window has a great influence on the heat transfer. • Differences in louver angles result in up to 45% difference in heat transfer. • Differences in flow types will result in a deviation of 70% in the heat transfer. • Correlations are proposed for the convective heat transfer from the louvered surface. The indoor venetian blinds are commonly used to block the solar radiation, which will also have an impact on the convective heat transfer from windows. The existing research on this phenomenon is almost based on reduced-scale experiments or simulations, which do not reflect the natural convection of actual windows. In this work, the natural convection near a full-scale window when louver close to the window ( n ≤ 10 mm) is firstly investigated by CFD simulation. Research indicates that the convective heat transfer from the full-scale window will be enhanced when the louver is closer to the window. The cause for the increased heat transfer is not only related to the thermal bridge effect of the aluminum louvers, but also to the type of flow near the window. Three different flow types will be generated along the window surface with venetian blinds during our simulation, which are named as Duct-directed flow (DDF), Transition flow (TF) and Louver-directed flow (LDF). The difference between the flow types will result in a discrepancy of approximately 70% in the convective heat transfer from the window. In addition, the influence of the slat angle φ , space from slats to window n and temperature difference between air and window Δ T on flow development and convective heat transfer has been investigated in this study. The correlation obtained from this work allows to accurately calculate the convective heat transfer from the full-scale window covered with venetian blinds, and the average error of the correlation is within 8.2%.

Effect of louver angle on performance of parallel flow heat exchanger

In order to study the influence of the louver angle on the heat transfer and flow resistance characteristics of a parallel flow heat exchanger, this paper establishes five calculation models including a uniform angle model and four variable angle models for comparing and analyzing the temperature, velocity, and pressure fields, and evaluates their comprehensive performance. The results show that the suitable choice of the v louver angle can lead to an optimal heat transfer effect and a best comprehensive performance.

Energy Balance Data-Based Optimization of Louver Installation Angles for Different Regions in Korea

A louver is a traditional environmental control device and passive architectural element based on an ecofriendly concept. Louvers are architectural elements that can be used to regulate natural lighting, thermal environment, and building energy use. To realize these integrated functionalities of louvers, they must be designed considering the climate and geographical characteristics of the target region. However, these aspects are typically not considered during building design in Korea, resulting in lovers being used as design elements with simple natural lighting control functions. Therefore, the objective of this study was to promote the integrated use of louvers by optimizing the louver angle according to the microclimate in Korea from the viewpoint of thermal energy use. We performed load and energy simulation planning and calculation and conducted optimization studies for the louver angle and range of motion for each region. The energy consumption in central and southern Korean regions was minimized when the angles of the fixed louvers were 45°–75° and 60°–90°, respectively. Kinetic louvers could enhance thermal energy management when installed at 30°–75° in spring, 135°–165° in summer, 75°–165° in autumn, and 45°–75° in winter. These findings can promote the realization of integrated functionalities of louvers from the perspective of indoor environment comfort based on the microclimates of the Korean regions.

Heat transfer augmentation in solar heat exchanger duct with louver-punched V-baffles

A vortex generator's ability to create secondary flow and accelerate rapid fluid mixing allows it to effectively improve thermal performance in a solar heat exchanger duct. A newly created louver-punched V-baffle (LPVB) vortex generator was tested experimentally in the current study and the flow and thermal patterns were also investigated using a three-dimensional CFD simulation. The Realizable k–ε turbulence model was utilized in the simulation and the predictions were verified using experimental data and correlations. By directing the impinging air onto the duct's heated surface, the square louver on the baffle served the primary function of reducing pressure drag. Air was used as the test fluid, flowing at Reynolds numbers (Re) from 5300 to 23,000 into the constant heat-fluxed duct. On the heated wall that was set up by letting the V-apex direct upstream, the LPVBs with a 45° attack angle (α) were repeatedly positioned. There were two aspects to the current investigation. First, the optimal relative baffle pitches (PR) and louver angles (β) conditions were determined by looking at the LPVB characteristics, which included four β and three PR at a fixed relative louver size (LR = 0.5) and baffle height (BR = 0.4). Second, three relative louver sizes (LR = 0.3–0.9) were investigated at the optimal PR and β. According to the results, the solid-baffle friction loss is significantly reduced by the LPVB with β > 0° while the heat transfer is slightly lower. In the first part, the LPVB with PR = 1.5, β = 45° has the optimal performance while in the second part, the one with LR = 0.9 yields the greatest performance. A numerical flow model was computed to understand the flow and thermal patterns. The findings were verified using the available measurements, and there is close agreement between the experimental and numerical results.

Entropy generation and thermal performance of tubular heat exchanger fitted with louvered corner-curved V-baffles

The current article deals with an experimental study on entropy generation analysis and thermohydraulic performance of a uniform heat-flux tube equipped with louvered corner-curved baffle tape (LCBT). Air was drawn into the inserted tube for the Reynolds number (Re) between 4760 and 29,300. The V-shaped LCBT arranged by V-tip in downstream direction was introduced with three baffle pitch ratios (PR = 1–2) and six louver angles (θ = 0–90°) for a fixed attack angle (α) of 30° and baffle height ratio (BR = 0.25). The impacts of investigated parameters on the thermal enhancement factor (TEF), Nusselt number (Nu), friction factor (f), and total entropy generation (S˙gen′) were examined. The measurements showed that the LCBT with the smallest values of PR = 1, θ = 0° give the largest Nu and f at about 4.4 and 19.2 times above the plain tube values, respectively. However, the greatest TEF around 2.23 was seen for employing the LCBT at PR = 1, θ = 45°. The entropy analysis also showed that the S˙gen′ is found to decline with the increment of PR and θ, whereas the minimal S˙gen′is at PR = 1, θ = 0° for lower Re but at PR = 1, θ = 45° for higher Re. Furthermore, the Nu and f empirical correlations for employing LCBTs were also proposed.

Numerical Investigation on The Effect of Grille Blockage Ratio on Air Flow Characteristics of Air Vents

Vents with louvers are an important component in the indoor heating, ventilation, and air conditioning (HVAC) system in providing a degree of freedom to the occupants to direct the air flow and prevent foreign objects from entering or exiting the air ducts. As a result, whether designing air ventilation or any duct design that involves louvers, the influence of louver design cannot be ignored. For vent design, aside from louver angle, blockage ratio is an important factor in air distribution due to its effect on pressure drop and flow distribution to indoor space. The blockage ratio is often described as the ratio of the projected area of the structure in flow direction to the cross sectional area of the domain around the structure. The purpose of this study is to investigate the effect of varying blockage ratios on the air flow characteristics of air vents including velocity and pressure drop. The chosen air vent model for this study is the Proton Wira air vent. Results are obtained using computational fluid dynamics (CFD) analysis and by utilizing the free and easily available open source software via Code-Saturne. The parameters were set according to available literature. The study finds that the pressure drop increases with the increasing blockage ratio. The velocity drops almost 7% for blockage ratio greater than 3 and the pressure drop increases more than 4%.

Numerical investigation of the air-side performance of louver fin-and-tube radiators having rectangular, tapered and airfoil section configuration

As the most widely used type in automobile industry, louver fin-and-tube radiator plays an important role in maintaining the stable operation of automobile. In order to further improve the heat transfer and flow performance on the basis of the original rectangular louver fin, a new type of airfoil louver fin was designed in this paper, and the air-side performance of airfoil, tapered and rectangular louver fin under different geometric parameters was numerically simulated by computational fluid dynamics (CFD). A total of fourteen samples are made and simulated with the corresponding louver angle (θ) being 23°, 26° and 29° and the louver length (Fl) are 1.2 mm, 1.4 mm and 1.6 mm respectively. The results reveal that the airfoil louver fin had the highest Nusselt number (Nu) and minimum friction factor (f) for all the studied cases. The Nu for the airfoil louver fin can be increased up to 4.9% over the rectangular louver fin and the corresponding pressure difference decreased up to 16.6%. However, because the heat transfer area of airfoil and tapered louver fin is slightly lower than that of rectangular louver fin, the heat transfer of airfoil and tapered louver fin is slightly lower than that of rectangular louver fin at θ=26° and 29° and low air inlet velocity. When the air inlet velocity is further increased, the heat transfer of airfoil and tapered louver fin is slightly higher than that of rectangular louver fin. Likewise, the heat transfer of airfoil and tapered louver fin is also slightly lower than that of rectangular louver fin for Fl=1.4mm and 1.6 mm. The heat transfer of airfoil louver fin is the highest at θ=23° and Fl=1.2mm.

Investigation of varying louver angles and positions on cross ventilation in a generic isolated building using CFD simulation

Louvers are an integral component of natural ventilation. This study presents a numerical analysis using computational fluid dynamics (CFD) on cross ventilation in an isolated building equipped with louvers. Opening configurations of (i) center-center, (ii) top-top, (iii) bottom-bottom, (iv) top-bottom and (v) bottom-top (whereby the configurations are defined as ‘windward’-‘leeward’) with varying louver configurations of No-Louver (NL), 0°, 15°, 30° and 45° are studied. Atmospheric Boundary Layer (ABL) condition is applied at the inlet of the flow domain and Renormalization Group (RNG) k-ε turbulence model with enhanced wall function (EWT) is employed for the numerical simulations. Grid sensitivity analysis is performed using Grid Convergence Index (GCI) whilst model validation is performed using Factor of two of observation (FAC2) analysis. The highest dimensionless flow rate (DFR) is achieved by configuration top-top without louvers at 0.719. The highest air exchange efficiency (AEE) is obtained by louver angle of 15° for center-center configuration at 53.4%. The lowest AEE obtained is obtained at louver angle of 0° for top-top configuration at 20%, indicating short-circuiting of air. For configuration bottom-bottom with louver angle of 30°, high AEE is obtained but at the cost of reduced DFR. The optimal balance between AEE and DFR can be obtained by factor-optimization (α) as presented in this paper. The study concludes that opening position alongside louver angle plays an integral role on the internal airflow, pressure coefficient, DFR and AEE in natural cross ventilation.