Gable Roof Research Articles

Macro Flow Dynamic Study of Wind Around a Gable Roof Building with Openings

Understanding the flow field developed in the proximity of a building due to the wind flow over it is a prerequisite for designing a building. The wind environment around buildings plays a pivotal role not only from the point of view of structural integrity but also impacts the ventilation performance, pedestrian comfort and dispersion of pollutants. With the emergence of the green building concept in the light of the sustainable living, modern buildings are equipped with various openings such as doors, windows and ventilators. These openings change the flow characteristics in and around the building remarkably and make the flow field much more complex. The current study seeks to improve the understanding of both the internal and external flow fields around the buildings with openings. In this work, an attempt has been made to investigate the influence of wind direction on the flow behavior of wind in and around gable roof buildings with six different opening configurations. Commercially available CFD software ANSYS-FLUENT is used for numerical simulations. The numerical simulations are carried out to solve the steady Reynolds Averaged Navier Stokes (RANS) equations. The results obtained from the numerical simulations are validated with the previously published experimental results, and a good agreement was observed.

Machine Learning of Usable Area of Gable-Roof Residential Buildings Based on Topographic Data

In real estate appraisal, especially of residential buildings, one of the primary evaluation parameters is the property’s usable area. When determining the property price, Polish appraisers use data from comparable transactions included in the Real Estate Price Register (REPR), which is highly incomplete, especially regarding properties’ usable areas. This incompleteness renders the identification of comparable transactions challenging and may lead to incorrect prediction of the property price. We address this challenge by applying machine learning methods to estimate the usable area of buildings with gable roofs based only on their topographic data, which is widely available in Poland in the Database of Topographic Objects (BDOT10k) of Light Detection and Ranging (LiDAR) origin. We show that three features are enough to make accurate predictions of the usable area: the covered area, the building’s height, and the number of stories optionally. A neural network trained on buildings from architectural bureaus reached a 4% median percentage error on the same source and 15% on the real buildings from the city of Koszalin, Poland. Therefore, the proposed method can be applied by appraisers to estimate the usable area of buildings with known transaction prices and solve the problem of finding comparable properties for appraisal.

Wind Load Analysis on Gable Roof of Low-Rise Building

The effect of pressure because of the winds on the exterior of gable roof of a low-rise single-storey building has been analyzed in present research using CFD simulation. Roof slope, which is most important factor for safety of structure was taken into consideration. Many past researchers have studied roofed structures but the majority of these researches have been carried on flat roofs, hip roof, spherical roofs, pyramidal roofs. There is need of researches that analyses effect of winds on gable roofs as these kinds of roofs are generally more susceptible to wind damage. ANSYS ICM is used for modeling and meshing and ANSYS Fluent for simulation. Results are extracted here using CFD post. In this very study three models with slope ang 10°, 20° and 30° with same incidence angle 0° were examined. This study analyses the effect of slope of the roof and angle of incidence of wind. The streamlines of velocity around the building model and pressure coefficient (Cp ) contours on the surfaces of the roof are opted here to represent the results. When results were plotted it was found that pressure coefficients were switching from negative to positive as the slope of the roof increases and the formation of vortex on leeward gets complicated as we go on increasing the slopes.

Variation of wind load distribution on gable roof building

Wind forces and their impact on the structural integrity of roofs and walls are pivotal considerations in architectural and engineering design. This study discusses the effect of wind load on gable roof buildings with varying slopes. Gable roof structures find extensive application in industrial construction projects. Based on wind tunnels with rigid models, wind pressure distributions on gable roof buildings with different aspect ratios were measured simultaneously. Special attention is required for the safe design of the building. Information regarding the wind pressure coefficients on buildings is available in codes of practices of various countries dealing with wind loads; however, such information is very limited. The present study will examine the suitability of four building models with roof angles of 10º, 15º, 20º, and 25º and will be analyzed using IS 875 (Part 3), and various forces will be calculated. Then, the same buildings will be modeled using STAADPro/SAP2000, and the comparison of the analysis will be made. Further, a building situated at various slopes on a hill will be modeled using STAAD-Pro/SAP2000, and the variation of Wind Forces along the slope will be studied. The expected results of this study will be finding out the most critical slope of a gable roof on a building and reducing the effect of wind forces on it. Furthermore, the most savior location of a building along the hill slope will be investigated, and the ways to reduce the effect of these wind forces will be studied.

Optimal orientation of the gable roofs covered with photovoltaic panels: Case study Kragujevac

Optimal orientation of the gable roofs covered with photovoltaic panels: Case study Kragujevac

Neighborhood, Topography, and Wind Direction Effects on Wind Pressure Distribution on the Low-rise Building Roof

Low-rise buildings are the majority of the houses that are constructed all over the world. Experiments of the wind loads acting on these buildings provide vital information to design secure structures and adverse weather conditions resistants, considering the basic parameters as roof slopes and the wind direction. This study estimated the distribution of wind pressures around the contour of buildings with gable roofs, considering diverse neighborhood conditions, namely the number and geometric configuration of buildings on the ground, in conjunction with the different angles of wind incidence and topography. The simulations took place with Ansys Workbench software, and the RNG K-Epsilon turbulence model and tetrahedral mesh were employed. The application validation of the CFD technique occurred in the double-sloped pitched roof structure. The results showed good concordance with the literature. The pressure coefficients were analyzed, as well, in the flow visualization, highlighting the attachment points and the recirculation zones.

The influence of attics space geometrical shape on ignition and flashover stages in residential building fires in dense settlements

As an artificial physical place, residential building is formed by various functional spaces, such as residential space and the space between the ceiling space and the roof, i.e. the attics. The phenomenon of fires in residential buildings in densely populated areas is suspected of having occurred in the attics. Hitherto, research on the fire space model concerning the stages of ignition and flashover usually employs the Steckler's compartment model in the form of a cube/box. On the contrary, the fire model with a triangular roof shape is still rarely studied. The purpose of this study was to analyse the influence of the geometric shape of the attics on the ignition and flashover stages in residential fires located in densely populated settlements. This study employs an experimental method by conducting scaled experiments of the geometric model of the ceiling space in the form of a triangular gable roof and shed roof, focusing on the ignition and flashover stages. The results showed that the ignition stage in the gable roof and shed roof models occurred in the 3rd and 4th minutes with a temperature ranging from 270 ⁰C- 476 ⁰C. The flashover stage also occurred in the 5th to 9th minute with regular results close to 500 ⁰C.

Using Greenhouse Modelling to Identify the Optimal Conditions for Growing Crops in Northeastern Thailand

The most essential components in escort farming are the determination of airflow patterns and the distribution impact of microclimate temperature variables. The objective of this study is to use Computational Fluid Dynamics (CFD) models to ascertain the aerodynamic and thermal dynamics of protected agricultural greenhouses suitable for cultivation in tropical Northeastern crops of Thailand by defining differences in greenhouse layouts, specifically Gable Roof (GR), Curved Roof (CR), Saw tooth roof (SR), and Double roof (DR). The root means square error (RMSE) indicated that the factor determination of CFD modelling using the standard k−ε turbulence model was satisfactory. In addition, they found that, at a significance level of 0.05, the average temperature in the greenhouses was statistically distinct based on the form of the back of the house and the location of the air input and outflow.

Numerical Analysis of the Roof Slope Effect on the Building Thermal Comfort and the Need for Roofing Materials in Tropical Area

Roof is the most affected building envelope element by local climate changes such as solar radiation, rain, wind, etc. The design of a building's roof will have a significant impact on the building's thermal conditions and comfort. This study aims to numerically analyze and optimize the slope of a gable roof on an 8 m × 12 m residential building with 3 m walls located in a tropical climate region. The parameter analyzed in this parametric study on galvanized steel gable roofs is the slope angle impact in the interval between 150 to 450, with an angle increment at 50. The thermal aspect of the analyzed building is modeled numerically using the TRNSYS simulation tool coupled with CONTAM for aerodynamic modeling. The results showed that the greater the roof slope angle, the more comfortable the room condition was due to the amount of heat release that occurred in the attic zone before penetration into the occupation zone. Otherwise, the greater the angle of inclination, the greater the roof geometry that leads to construction material addition for the frame and roof covering. Therefore, it is necessary to perform numerical analysis to determine the optimal slope of a gable roof that provides maximum thermal comfort in a room with low roofing material requirements. Analysis and optimization of convective heat dissipation from the attic zone through natural ventilation or infiltration to reduce indoor thermal gain is an outlook for further research.

Experimental and numerical aerodynamic analysis of an elevated beachfront house

Elevating coastal houses enables residential communities to reduce the risk of flooding due to tropical cyclones. However, wind-induced damage during such events requires an understanding of the inherent wind forces to improve damage mitigation techniques and assessment of climate-related risk in insurance models. In this study, wind-tunnel experiments and computational fluid dynamics (CFD) simulations are conducted for a typical elevated 1:25 scale beachfront house, possessing a 5:12 pitched gable roof with overhanging eave. An atmospheric boundary layer (ABL) wind field is generated in a low-speed wind-tunnel to replicate conditions experienced during tropical cyclones. Testing is performed for a range of incident wind angles to understand the full aerodynamic consequences of strong winds. Measured pressure coefficient (Cp) distributions are compared with CFD simulations using steady-state and transient Delayed Detached-Eddy Simulation (DDES) within ANSYS Fluent 2021 R1. Net Cp values surrounding the overhanging eave are considered to evaluate the role of this typical geometrical feature. It was found that larger uplift suction occurred at incident wind angles of 45°and above, after which the suction remained stable. The roof panels are subjected to the greatest upward suction, where critical regions occur at the roof ridge. The size of the low-pressure regions is determined by the incident wind angle and ensuing flow separation wherein DDES is found to reproduce additional aerodynamic features arising from unsteady turbulent flow. DDES offers improved predictive capability when mean pressure forces are considered but falls short as an accurate means to efficiently evaluate peak Cp distributions.

CFD Simulations of Snowdrifts on a Gable Roof: Impacts of Wind Velocity and Snowfall Intensity

Roof structures are suffering serious threats caused by unbalanced snow distribution, especially long-span spatial structures, such as gable roofs. The formation of unbalanced snowdrifts on the gable roof is affected by the meteorological condition and the drifting snow. This study was conducted to explore the snowdrift characteristics on gable roofs under different snowfall conditions based on a new Eulerian–Eulerian multiphase approach. To consider the diffusive process of snow in different states, the governing equations of air and snow phases were modified separately according to the actual transport process. Additional terms based on the deposition/erosion process were inserted into the governing equations to consider the processes of snow particles being trapped or ejected by snow surface. The feasibility of the new model for the snowdrift was validated by comparing with a field observation. Then, the snowdrifts characteristics on typical gable roofs were investigated under different wind velocity and snowfall intensity conditions. The formation mechanism of snowdrifts and the influence of meteorological conditions on snowdrifts were clarified by analysis. The results show that the uneven distribution of snow on the gable roof becomes more significant with the increase in wind velocity. Furthermore, the distribution of snow on the roof tends to be more even in the case of heavier snowfall.

Reliability of toe-nail connections in a gable roof houses under uplift wind loads

The latest devastating hurricanes have caused considerable damage to light frame wooden houses. The detachment of the roofs because of the high uplift wind loads is one of the typical damages. This detachment often occurs at the contact connections in between the roof trusses and the walls of the houses. For several decades, toe-nail connections, which are poor in uplift resistance, have been used in those contacts. The purpose of this paper is to develop an efficient numerical model for performing reliability assessment of wooden roofs under uplift wind loads taking into account the statistical variability in both the load–deflection curve of toe-nails and the uplift wind load. The model utilizes a three-dimensional semi-analytical solution previously developed to predict the behaviour and failure of wood roofs under spatially variable uplift loads. The random characteristics of the toe-nails were calculated based on experimental results found in the literature and were statistically simulated using a beta distribution. The randomness of the wind speed was evaluated using a normal distribution. A full-scale gable roof was considered as a case study to determine the probability of roof failure at different wind speeds, Monte Carlo simulations along with the semi-analytical model were used to obtain the fragility curve based on two different criteria. It was found that beyond a mean wind velocity of 32 m/s, the probability of roof failure increases rapidly.

Effect of gable roof with various roof pitches and obstacle heights on natural ventilation performance for an isolated building

Numerical analysis based on CFD steady RANS equations was used to study the airflow characteristics around and within an isolated gable roof building. Parameters that are the main study focus of this research include: streamlines of normalized velocity, pressure coefficient and ventilation rate. The effect of gable roof with four different roof pitches namely 15º, 25º, 35º & 45 were investigated against varying obstacle heights of 40, 50, 60 & 70 mm. From the simulation results, the streamlines show that larger roof pitch leads to increased velocity at the window and roof openings due to the external and internal pressure difference in the building. The corresponding increment in internal obstacle height on the other hand leads to gradual alteration of airflow direction in front of the obstacle, and also an increase of the pressure coefficient inside the building because of wind blocking effect. This pressure coefficient also sees a reduction in value at the windward and inside of the building with an increase in steepness of the roof pitch due to increasing internal velocity. Hence, airflow behavior and characteristics are clearly dependent on roof pitch and internal obstacle height which indicates a good agreement with the findings from the previous studies. Gable roof with a steeper roof pitch building coupled with lower internal obstacle height will therefore yield better ventilation rates.

Method to assess the potential of photovoltaic panel based on roof design

The photovoltaic (PV) panel makes it possible for everyone to produce electricity in their own house. However, the panel is quite a costly investment and requires much consideration to maximize its potential. The roof has variables that would impact electricity generation. The roof of housing in Indonesia was built generally in a complex shape, a combination of gable and hip roofs. This research is conducted to break down factors affecting PV productivity in regard to the roof’s aspects. A computer simulation using Ladybug plugin in Rhinoceros software has been done to achieve the target. Initially, the performance of PV panels on the gable, and hip roof, is analyzed respectively. It is found that the roof’s slope, and orientation, contribute more to the amount of electricity produced than the shape itself. These factors were used to assess the PV potential in several housing models employing simple and complex roof (more than 2 surfaces) construction in the city of Gorontalo. Eventually, a comparison between the estimation of real PV production on housing, and the estimation provided by the simulation is conducted to verify the assessment method. The difference is about 4%, as proof the simulation result is reliable.

PERANCANGAN FASILITAS KAMPUNG WISATA DI SUNGAI JINGAH BANJARMASIN

Banjarmasin holds rich history and culture along its riversides which is supposedly to be conserved. Regarding this, the Department of Tourism of Banjarmasin City created a program Called Kota Pusaka and are willing to develop Sungai Jingah’s riverside settlement to become a Tourism Village. In this work of planning the writer applies Infill Design method to synthesize designs corresponding the surrounding houses, whether it would be matching or given the context of nowadays technology and materials. Infill Design also allows for contrasting designs to be formed. The purpose of applying Infill Design method is to add the functions of tourism into the existing settlement. The results are that the area able to be built on are empy sites and sites with broken down houses. The mass shapes for matching and compatible buildings and elements are gable roof or stepped-up roof. The mass shapes for contrasting buildings and elements are composed of transformed shapes with folds and rolls.

Hydrothermal Evaluation of Vernacular Housing: Comparing Case Studies of Waste PET Bottles, Stone, and Adobe Houses

This work shows the humidity and thermal evaluation of different case studies of houses. The analyses focused on room prototypes and houses built in different regions of Querétaro, México. Three different climatic zones were included with the evaluations of houses and prototypes. The assessments of internal and external parameters in residential buildings are also shown. The internal parameter measurements were done with hydro-thermometers and thermography images. Six structures were evaluated, one of the conventional housing materials and five of alternative or vernacular materials. The predicted mean vote (PMV) and the predicted percentage dissatisfied (PPD) were determined using the average temperature and relative humidity values, and they were considered to be dynamic because they can change depending on many factors. The six dwelling insulating properties were associated with their construction materials, design, location, and other factors. The six houses have many differences, but considering their behavior in their location, the two floor porous stone house got the best results. On the contrary, the flagstone house with a gabled roof of galvanized sheets had a cold perception despite many advantageous elements, failing to provide comfort in such a cold location. Contrasting these with other adobe constructions, the analyzed one had low thermal insulation, which was explained by its characteristics. PET and adobe uninhabited prototypes had medium to cold perceptions. The PET prototype has excellent and adjustable insulations, both on temperature and RH, considering the passive illumination and ventilation of its glass bottle skylights.

Wind loading on a low-slope gabled roof: Comparison of field measurements, wind tunnel data, and code provisions

The current wind load provisions for low-slope roofs in the NBCC were established in the 70 s with wind tunnel experiments using analog data technology. These coefficients have remained almost unchanged. As the wind pressure measurement tools have significantly improved during the past 50 years, verification of the original pressure coefficients is required. The National Research Council of Canada (NRC), in collaboration with the Special Interest Group on Dynamic Evaluation of Roofing Systems (SIGDERS) consortium, conducted a wind load investigation to verify the suitability of the current wind load provisions. The investigation was carried out using both field measurements and wind tunnel simulations. An ideal full-scale representation of the low-slope roof specified in building code was instrumented and continuous data was collected for four years. A duplication of the building was evaluated by two wind tunnels to investigate the effect of critical wind directions. The paper presents the efforts made to make field measurements comparable to wind tunnel data and code provisions. It was observed that records with mean wind a speed above 22 mph (10 m/s) reduce the data variability and maximize reliability, which are important features for the code verification process. The goal of this research is to combine multiple sources of data to verify the suitability of wind load provisions on low-slope roofs. The research focuses on NBCC-2020 as an application. Evidence is presented that the NBCC-2020 provisions for the Roof Edge Zone is currently underestimated and needs to be increased. The study suggests taking the opportunity of Edge provision enhancement to merge Corner and Edge into a unique “Perimeter” load provision. The suggested code change addresses the current underestimation of the Edge Zone coefficients (wind load upgrade), and provides construction simplification to minimize roofing failure associated with labour-induced errors during cladding system installation (constructability upgrade).

BIMBINGAN TEKNIS PERENCANAAN MENARA MASJID RADEN RAHMAD MERJOSARI LOWOKWARU KOTA MALANG

The minarets are a distinctive traditional feature of many mosques, although they vary in height, style, and number. Towers can be square, round, hexagonal, octagonal, or even spiral and towers are usually covered with a gabled roof. Mosque minarets Generally a tall minaret with a cone or onion-shaped crown, usually standing alone or higher than the surrounding structures. The basic form of the tower includes a base, shaft, and gallery. The style varies according to region and time period. The minaret provides a visual focal point and is traditionally used for the Muslim call to prayer (Azan). A good tower must be designed according to the shape of the mosque and the structural needs are calculated.

Η Παναγία Γαλακτοτροφούσα στην Ανθούσα Τρικάλων παρά τον Αχελώο ποταμό

The Virgin Galaktotrophousa (1799), the main church of an old monastery close to the village Anthousa near Trikala in the region of Aspropotamos, is a single-nave church with an abbreviated dome, lateral apses and a later narthex to the west. Above the narthex there was a chapel dedicated to the Beheading of Saint John the Forerunner. It is covered by a gabled roof from which the dome springs. The protrusion on the exterior of the tiled roof of the west part of the naos leads to the hypothesis that the narthex was vaulted, possibly with a shallow dome. The abbreviated form of the dome, the placement of a chapel above the narthex, and the latter’s shallow dome are common practices in the wider region of Aspropotamos.

영덕 장육사 대웅전 벽화의 도상과 특징

As a building of Joseon Dynasty, Daeungjeon Hall at Jangyuksa Temple has jusimpo type gable roof with three bays in the front and three bays on the side, and inside the Hall, it attracts the attention of wall paintings and dancheong drawn on the wall and ceiling as well as Buddha statues and Buddhist paintings. Wall paintings and dancheong which make the interior of the Hall look majestic are usually drawn small because they are painted in the sense to focus attention on Buddha statues or Buddhist paintings as the main object of worship and form a religious atmosphere, but it receives attention since the east and west wall of Daeungjeon Hall at Jangyuksa Temple show unique iconography that is not seen in wall paintings of other temples. This paper looked into the layout focusing on wall paintings the inside of Daeungjeon Hall at Jangyuksa Temple and examined the iconographic origin of the iconography that is distinguished from wall paintings of other temples, such as Munsudongja(Child Majusri) on a lion, Bohyeondongja(Child Samantabhadra) on a white elephant, and Bicheon(aprasas) playing a musical instrument, etc. as well as the development process. This iconography was established as solo iconography in earlier period of wall paintings, and it was found that it had an influence on banner Buddhist paintings of Seoul&Gyeonggi area be drawn at the bottom from the end of the 19th century to the early 20th century. However, Arhat paintings and Portraits of Great Masters on Pobyeok wall show characteristics after the 19th century in the iconography, coloration, and detailed expression, so it is believed that they were repainted after a rebuilding. Then, based on the records handed down to the temple, the creation period of the wall paintings was examined. Most of the wall paintings the inside of Daeungjeon Hall were created in 1764 during a ceremony of Buddhist paintings, in which leading monk painters Doohoon(斗訓) and Jaeok(再玉) participated, and it can be said that they have great material value as representative works showing the iconography of Gisamunsudongja(Child Majusri on a lion) and Gisangbohyeondongja(Child Samantabhadra on a white elephant) in the mid-18th century.