Pitched Roof Research Articles

Wind loads on solar panels mounted parallel to pitched roofs, and acting on the underlying roof

This paper describes an investigation of the net wind loads on solar panels and wind loads on the underlying roof surface for panels mounted parallel to pitched roofs of domestic buildings. Typical solar panel array configurations were studied in a wind tunnel and the aerodynamic shape factors on the panels were put in a form appropriate for the Australian/New Zealand Wind Actions Standard AS/NZS 1170.2:2011. The results can also be used to obtain more refined design data on individual panels within an array. They also suggest values for the aerodynamic shape factors on the roof surface under the panels, based on a gust wind speed at roof height, of ± 0.5 for wind blowing parallel to the ridge, and ± 0.6 for wind blowing perpendicular to the ridge. The net loads on solar arrays in the middle portion of the roof are larger than those on the same portion of the roof without any solar panels, thus resulting in increased loads on the underlying roof structure.

Insulation systems of the building construtions

Constructions of the exterior insulation and decoration combines materials of different functionality and constructive solutions allows to these materials to demonstrate their efficiency to the great extent. Fire safety of buildings is mandatory requirement for building systems. Some insulating material may belong to the group of combustible, but their use in structures so as to minimize the risk of fire. On the other hand, there are special designs, in which non-flammable insulation acts as a flame retardant barrier. In the article carried systematization of construction systems used in the flat and pitched roof during the insulation and wall covering and facades. Taking into account the experience of leading firms were considered the application features of using exterior finish systems: construction solutions, requirements for materials and recommendations about the installation these systems.The article deals with the construction ventilated roofing system of two types: flat roof and pitched roof seam. In the first case, the ventilation system is created using milled insulation boards in the second - by a ventilated gap. In both cases the natural convection of air in the air cavities. Ensuring operational stability insulation is laid on the stages of production of heat-insulating materials. It is important: firstly responsible execution of all process operations associated with providing regulatory properties of materials and secondly, the performance of additional operations associated with the produc-tion of materials, working in a specific design. An example of a material whose properties can modify for a particular application, are milled mineral wool (with air channels) for systems of ventilated flat roof.

Designing and Testing of the Recycled Vegetative-Retention Layer of the Vegetative Upper Skin of the Pitched Roof

This article is focused on the development and efficient application of the vegetative-retention layer for pitched turf roofs with average inclination of 25°. Developed material is composed of the recycled polyester fiber mat with clusters of the same milled recyclable waste without added chemical binders. Important part of the considering evaluation is the consecutive optimization for prospective development of the pursued layer especially focused on the selected density, thickness and roughness of the fiber mat surface.

Environmental Impact of Green Roofing: The Contribute of a Green Roof to the Sustainable use of Natural Resources in a Life Cycle Approach

Abstract Even if several studies and researches have demonstrated that green roofs significantly contribute to energy saving, indoor thermal comfort, urban heat island mitigation, rain-water management and air pollution reduction, environmental benefits of green roofs mainly depend on use of primary energy, natural resources or raw materials used in the construction. A green roof is usually a more or less complex aggregation of different layer addressing each one to a specific characteristic and performance. Results of previous LCA researches, based on a cold climate scenario, have demonstrated the highest influence that some specific layers have on the overall impact of the green roofs and to what extent the global impact changes when insulation and the substrate layers vary in density and quality. Starting from results of these similar EU researches, this study aims to evaluate the variation of the overall impact in hot climates where insulation is less strategic than heat capacity. LCA has been applied to assess and compare the environmental impacts of four different green roof solutions compared to a standard clay pitched roof, based on the functional unit of 1m 2 with the same reference service life, where layers have been selected according to local practice and market. Despite a general equivalence in environmental impacts of all the roofing elements, results have highlighted a general lack in specific life cycle inventory information that leads to a potential inaccuracy of the assessment especially when recycled material are used in the growing medium or when disposal scenario includes recycle processes.

Pitch and Flat Roof Factors’ Association with Spatiotemporal Patterns of Dengue Disease Analysed Using Pan-Sharpened Worldview 2 Imagery

Dengue disease incidence is related with the construction of a house roof, which is an Aedes mosquito habitat. This study was conducted to classify pitch roof (PR) and flat roof (FR) surfaces using pan-sharpened Worldview 2 to identify dengue disease patterns (DDPs) and their association with DDP. A Supervised Minimum Distance classifier was applied to 653 training data from image object segmentations: PR (81 polygons), FR (50), and non-roof (NR) class (522). Ground validation of 272 pixels (52 for PR, 51 for FR, and 169 for NR) was done using a global positioning system (GPS) tool. Getis-Ord score pattern analysis was applied to 1154 dengue disease incidence with address-approach-based data with weighted temporal value of 28 days within a 1194 m spatial radius. We used ordinary least squares (OLS) and geographically weighted regression (GWR) to assess spatial association. Our findings showed 70.59% overall accuracy with a 0.51 Kappa coefficient of the roof classification images. Results show that DDPs were found in hotspot, random, and dispersed patterns. Smaller PR size and larger FR size showed some association with increasing DDP into more clusters (OLS: PR value = −0.27; FR = 0.04; R2 = 0.076; GWR: R2 = 0.76). The associations in hotspot patterns are stronger than in other patterns (GWR: R2 in hotspot = 0.39, random = 0.37, dispersed = 0.23).

Volcanic ashfall accumulation and loading on gutters and pitched roofs from laboratory empirical experiments: Implications for risk assessment

Volcanic ash load is dependent on the migration and accumulation of ash on roofing surfaces and guttering, of which limited research has been conducted. This study investigates this knowledge gap through the empirical experimental testing of volcanic ash on variably pitched metal sheet roofs with modern PVC gutter systems, highlighting the relative importance of accumulation, migration, remobilization, saturation, and subsequent load.A testing rig delivered ash onto variably pitched roofs (pitches 15°, 25°, 30°, 35°, and 45°) with two 45° tests involving a wet surface with subsequent ashfall, and the second of ashfall with periods of wetting, followed by wetting until failure. In testing, dry ash on a dry roof accumulates at pitches up to 35°, above this pitch the percentage of ash accumulating reduces with greater percentages infilling guttering and or lost to the ground. With the introduction of a wet roof surface at 45° pitch, adherence of dry ash greatly increases, increasing accumulated ash thickness as compared to dry tests from 8% to 38%. For testing involving periods of wetting at 45° roof pitch, accumulation percentages further increased to 50%. Ash migrating from the roof surface filled guttering more rapidly at greater pitches, which once full resulted in further migrating ash to spill over the front or back gutter lips. Collapse of guttering did not occur during testing, but deformation and bracket detachment did occur at loads >1kPa.This study provides data on load calculations on roofing and PVC guttering through the quantification and utilization of relationships between ash fate, pitch, and the influence of water, in the development of two scenarios for both roof and gutter. These two scenarios then enable the estimation of ash accumulation and thus the load and collapse thresholds for roof and gutter at different roof pitch, which could be adopted for volcanic risk modeling or risk management.

Efficiency of Monitor Roof in Maintaining the Thermal Conditions of Indoor Air and Water in a Medium Scale Enclosed Tropical Prawn Hatchery Building

This paper investigated the effects of roof design on the thermal conditions of indoor air and larviculture tank water of a tropical freshwater prawn Macrobrachium rosenbergii (de Man 1879) hatchery building. The research method was through a simulation study, using Integrated Environmental Solutions Virtual Environment (IES VE) software and the building modelled was based on an existing medium scale enclosed freshwater prawn hatchery. Monitor roof (vented ridge) was compared with the existing pitched roof design. The results showed the vented monitor roof design provided a considerable improvement to the indoor thermal environment of the prawn hatchery. The indoor air temperatures recorded under the monitor roof was close to the upper human acceptable thermal limit (34.0 °C) and some of the thermal readings were adequate for humanly comfortable condition. The indoor air temperatures became totally acceptable for the occupants during daytime through the installation of reflective aluminium foil (RAF) to the monitor roof. Therefore, the combination of monitor roof and RAF was recommended to achieve acceptable indoor air thermal condition for occupants while successfully maintaining the water thermal requirement for optimal prawn larval growth.

Building Integrated Photovoltaic Market trend and its Applications

The development of BIPV technology and their implementation in construction of building envelop provides an aesthetical, economical and technical solution. This paper presents the building envelope products, and their properties. BIPV products for pitched roof, flat and curved roof, transparent and semi-transparent facades and skylights have been highlighted in the paper. The properties of BIPV products include solar cell efficiency, open circuit voltage, and short circuit current, maximum power and fill factor. Few successful worldwide existing BIPV Projects with different product categories are also listed in a tabular form. The major considerations for a successful project are proper orientation of BIPV module, suitable distance between buildings, avoidance shadow effects and suitable architectural considerations BIPV technology is a sustainable and cost effective method and the future of this technology is promising as it creates zero energy and zero emission buildings. DOI: http://dx.doi.org/10.11591/telkomnika.v14i2.7338

Wind potential evaluation around isolated pitched roof buildings

The knowledge of wind field characteristics around buildings is very useful in a variety of applications such as energy supply by means of a domestic wind turbine. In this paper, results of a wind study around a conventional pitched roof building are given in order to choose the best location and therefore to maximize a micro-wind turbine production. Numerical results on a bluff body (cube) have been performed by means of computational fluid dynamics techniques and the Reynolds Averaged Navier-Stokes approach has been used to model the flow. Several turbulence models coupled to different near-wall treatments have been tested and have thus allowed one to determine the optimal configuration. Numerical model validation through the experimental data available in literature has made it possible to extend the study to a cube equipped with a pitched roof. Both sets of results thus obtained have allowed one to discriminate the effects from this particular element. Some of the computed data will be given in this paper in order to highlight the most significant regions relative to wind potential for a range of wind incidence angles. Some over speed areas have been found in the vicinity of the pitched cube for low altitudes. Finally, a simple method to map wind potential around buildings is proposed and a case study is presented. It deals with wind potential estimation for an isolated pitched roof building in Valenciennes (North of France). It is shown that some areas are beneficial for a micro wind turbine installation, even close to the building.

Measurement of the Influence of Roof Pitch to Increasing Wind Power Density

Abstract The wind flows on the rooftop house in Semarang, Indonesia past were examined in a Computational Fluid Dynamics (CFD) analysis and indicate best performance for wind energy power density. The rooftop pitches of house can have huge impact on increasing wind power density. This paper deals with the study to increase wind power density of micro-wind turbine located on the rooftop house by design the roof pitch. CFD was performed to evaluate the performance of wind flow around the roof pitch of housing at different angle (20 o , 30 o , 40 o and 50 o ) based on wind climate data analysis. The results showed that a pitched roof of 30 o has the best wind potential density than another for same base house model height.

해상컨테이너를 이용한 대학생기숙사 거주 활용 계획 연구 - 암스테르담 대학생기숙사 키트보넨 사례를 중심으로 -

The purpose of this study was suggested to establish of student housing by using shipping container. The research method are a study of shipping container and characteristics of student housing by using shipping container, compared typically student housing with student housing by using shipping container. Also there are planning though a case study of various planes and survey based on the student housing city in Amsterdam, Netherland, is called Keetwonen. It is a planning for housing unit to actual build at the part of land to devise master plan The 40FT(High Cube) Shipping Container housing unit are double occupancy room with toilet and balcony. The common areas are the kitchen, laundry facilities, conference room and lounge are available on the first floor with a lightweight steel frame construction method applied for obtain substantive utilization of the space. Considering into the type and scale of site shall be planning in the form of side corridor and central corridor, which is preferable to separate the interior space into two areas by a central corridor to secure personal privacy. Also, planning such as a separate exterior panel, color and landscape design to improve the external image of the container and block the solar radiation heat influx with a pitched roof. Allow 24 college students shall live at the site of Seongnae-dong, Gangdong-gu in Seoul, Korea (site area ), including common facilities and a lounge with a building that has three stories above ground were established to build plans to target the actual land.

CYCLONE DISASTER ON HOUSING AND COASTAL AREA

Cyclones are the Natural hazards which create huge economic loss and loss of Lives..In the present study, the orision of cyclones in the months of May, October and November are discussed.The cyclone tracks in the month of November for the past 100 years is presented. The Delta areas of major rivers, Eastern ghats, thechanges in Environmental conditions of an area and changes in Temparatue will contribute in deciding the cyclone tracks .The pressure distribution and stress distribution around the roof and walls of a pitched roof house is discussed. It is also noted that the design wind speed of coastal area of East coast in the IS code shall be revised due to increase in wind speed of the recent super cyclones.

Effect of Opening the Sash of a Centre-Pivot Roof Window on Wind Pressure Coefficients

This paper describes the effect of outward opening the sash of a window on local and overall wind pressures. Wind tunnel experiments were used for the purpose of evaluation. A centre-pivot roof window on a pitched roof in a modelled scaled building was used in the analysis of wind pressures. The wind pressures were defined in terms of wind pressure coefficients. Traditionally, wind pressure coefficients are extracted from the analysis of a sealed plane surface. These wind pressure coefficients are used to estimate the natural ventilation rate through windows/openings due to wind effect. Surface averaged wind pressure coefficients do not accurately estimate the airflow rates. Therefore, local wind pressure coefficients are needed, especially for dynamic calculation of airflow rates. From the wind tunnel experiments, it is concluded that outward opening the sash can significantly affect the wind pressure distribution near to the window. The use of wind pressure coefficients from the analysis of a sealed plane surface may lead to erroneous estimation of airflow rate.

Fly proof net shed for livestock: A novel concept of physical barrier for integrated management of Culicoides spp. (Diptera: Ceratopogonidae)

Aim: An age old and time tested technique of mosquito net requiring no energy, used by humans since prehistoric period was the inspiration behind this novel technique of fly proof net shed for livestock. With the aim to develop similar type of net shed for animals, which will protect them at night from biting of range of insects from Culicoides midges to mosquitoes, research was undertaken. Materials and Methods: Net shed with pitch roof (gable type) was erected for use of livestock. The open inlet area was covered with 40 mesh size wire net. The roof at attic level was fitted with hurricane type of ventilator. Shed was used for animals at night hours only. vane anemometer was used for estimation of temperature and wind related parameters. Thermal humidity index (THI) and air changes were calculated as per the standard formulas. Based on these parameters suitability of shed was judged. Results: It was observed that, due to netting of the shed population of Culicoides and other flies and incidences of their bites at night hours were considerably lowered. As a result, animals were found comfortable, and their body movements undertaken for wiping off these flies were significantly reduced from 196.50 to 22.16. All it accrued to increased milk yield to the tune of 18.97% in the net shed buffaloes as against control shed. Studies on suitability and comfort to animals were tested by estimating THI and air changes per hour in the net shed, which also revealed the estimates in comfortable regimen and ventilation, remained not much affected despite of netting. Other parameters studied for testing its more accuracy by taking other species of animals as kids, for them also, shed was found suitable through estimation of various physiological and behavioral parameters. Finally, the efficacy of shed was judged on the basis of cost effectiveness. Highly encouraging results on the above said parameters endorsed the effectiveness of the technique. Conclusion: A net shed with pitch roof (gable type) fitted with hurricane type ventilator at its top serves the purpose of a physical barrier to minimize host-pest contact. Observations recorded in the experiment are sound enough to conclude and to recommend the use of net shed for livestock.

Optimization of Design of Pitched Roofs According to Phase Shift of Thermal Oscillation

It is important to take into account some more parameters, e.g. heat transfer coefficient, hygienic criterion or globalised energetic criterion, nowadays. It is a time when there is a big emphasize on thermal protection of residential buildings. Therefore an important calculation parameter is spoken more often - temperature loss and phase shift of thermal oscillation. This two parameters are very important especially in case of building envelopes based on lightweight supporting and used insulation materials. A pitched roof in residential building or family house is a typical example. This problem is growing even more, if we are taking adverse ratio of outer surface to volume of the space into account. This paper is showing analysis of such building envelope construction, its designing and influence on optimal values of phase shift of thermal oscillation.

Steel roofing disaster and the effect of the failure of butt joints

This article scrutinises the causes of a disaster of a pitched roof construction made of welded plate girders. The girder construction elements were assembled with bolted butt joints. The roofing was made of a folded sheet supported by steel purlins that transferred the load onto welded plate girders. The purlins had no roof bracings. In the analysed case, several days of abundant snowfall preceded the failure that caused a collapse of the roof of a production hall. The investigations that followed confirmed that the collapse started with the cracking of the bolts used to centrally join the roof girders. In the course of the analyses and calculations, it was established that the main cause of the disaster lay in a faulty design of the butt joints between the segments of the steel plate girders. Another factor having impact on the failure was the numerous mistakes in the design and fitting of the steel purlins. The excessive snowfalls were not the main cause of the disaster but were only an additional one. The article also provides a concept for the reconstruction of the damaged building and provides additional details concerning the refurbishment phase.

Three-Dimensional Wind Field Simulation on the Two Typical Roofs of the Building

Wind energy utilization in the building environment has the advantage that it can avoid transporting effectively, especially it has important significance for residents without electricity. This paper mainly analyzed the basic situation of three-dimensional wind field around the buildings with the theoretical analysis and CFD numerical simulation method. By simulating the wind with different directions and different speeds, the characteristics of the wind field around single flat and pitched roof building are analyzed.

Investigation of Passive Design Techniques for Pitched Roof Systems in the Tropical Region

Pitched roof design represents the common system for the most tropical houses in Malaysia. Different angles and colours of this roof deliver various impacts on the indoor environment. This study focuses on estimating the amount of heat gain and roof surface temperature obtained from different roofing aspects. The paper hypothesizes that colour technique could change pitched roof design more than roof angles and materials. The research was based on simulation analysis applied on an actual room size with different roof angles (0°, 30°, 45° and 60°) in the Malaysian environment. As a result, the findings of different roofing systems affirm the hypothesis and show the significant of roof colour compare to area, angles and materials. This study contributes efficiently to the knowledge of the roofing design in the tropics. In addition, it will shed light on the economic sector and sustainability for optimum roofing concept particularly for low cost housing components in Malaysia.

도시경관 자원으로서 건축문화재의 활용 방안에 관한 연구 - 제천 엽연초생산조합 구사옥을 중심으로 -

This study aims to find the optimum method to reuse as townscape resource and to preserve the architectural heritage. And, it wants to contribute the policy of the architectural heritage and townscape. This research is targeted at an old office building of Leaf tobacco Producer' cooperation, designated as a cultural assets in Jecheon. It investigated the design characteristics of an old office building of Leaf tobacco Producer' cooperation and the streetscape of Uibyeong-daero 12-gil. It was conducted using the research methods of the field survey, and it was to analyze and to compare the various existing data and a current status. The result are as followings. Firstly, we should be consider the policy of architectural heritage that a sense of place can be preserved. Secondly, we should be consider the linear method of the conservation and reuse in urban street that the architectural heritage is located at least. Thirdly, if it will be to maintain the facade of the building adjacent to the street using the design characteristics of an old office building of Leaf tobacco Producer' cooperation, Uibyeong-daero 12-gil will be made a unique street that will be represented the history of leaf tobacco produce. Lastly, it has been analyzed that the design characteristics of an old office building of Leaf tobacco Producer' cooperation are the arch of entrance, the arched window, the rectangular window, the entabature, the horizontal joint, the finish of cement mortar, a pitched roof, etc. And, the design guideline and the maintenance plan of Uibyeong-daero 12-gil have made.

Effects of spectral albedo on solar photovoltaic devices

Although the spectral effects of direct and diffuse radiation on solar photovoltaic (PV) performance are relatively well understood, recent investigations have shown that there can be a spectral bias introduced due to albedo from common ground surfaces that can impact the optimal selection of PV materials for a known location. This paper extends analysis to the effects of spectral bias due to the specular reflectivity of 22 commonly occurring surface materials (both man-made and natural) and analyzes the albedo effects on the performance of seven PV materials covering three common PV system topologies: industrial (solar farms), commercial flat rooftops and residential pitched roof applications. An effective albedo is found for each surface material and PV material combination, which can be used in lieu of broadband albedo values in PV simulations. These results enable PV material selection for specific environments enabling geographic optimization for the micro-environment, while at the same time assisting optimal surface selection in the vicinity of existing or planned PV arrays. This analysis is of particular significance for the modeling of performance of bi-facial PV modules and vertical BIPV.