Roofs Of Residential Buildings Research Articles

EVELOPMENT OF THE METHODS FOR SURVEYING THE TECHNICAL CONDITION OF THE RESIDENTIAL BUILDINGS’ ROOFS FOR THE PLACEMENT OF ELECTRIC SOLAR BATTERIES

Problem statement. In Ukraine, green energy, in particular, solar power plants, is developing rapidly in recent years. Their power depends on the area of solar panels, so large land plots are required for powerful plants. In the context of urban development, there are almost no free plots. It is proposed to place such stations on the roofs of residential buildings. The problem is that in order to implement this, it is necessary to investigate the technical condition of the roof structures. To do this, it is necessary to develop technique for surveying the roofs’ technical state. The purpose of the work is to classify the survey objects, with further development of the visual observation methodology, instrumental measurements, selection of facts, and establishment of links between them. Method. The methods of visual observation, instrumental measurements, data accumulation, selection of facts, and establishing links between them were used to develop the classification of the survey objects. The types of residential buildings that were built from the 30s to the 80s of the last century on the territory of Ukraine were studied. The investigation of urban residential buildings for the purpose of their classification was conducted according to consumer and operational characteristics. The result of the research is the development of a technique for the application of research methods such as visual inspection, instrumental measurements. A technique for surveying the technical state of those types of roofs that were included in the classification based on the study of existing residential buildings was developed. The scientific novelty is that the technique is developing for the first time for surveying the technical state of roofs and garrets, for the tasks of placing electric solar stations on their surface. Practical value. With the help of the developed technique, it will be possible to conduct a survey of the technical condition of roofs and garrets for the placement of solar stations on their surface by all organisations that are engaged in such work and have the necessary experience and tools. Conclusions. A classification of types of roofs and garrets of residential buildings was developed for the possible location of electric solar batteries on their surface, as well as a technique for surveying the technical state of roofs and garrets structures was developed.

Thermal Performance of Residential Roofs in Malaysia: Experimental Study Using an Indoor Solar Simulator

Previous researchers have detailed the problems in measuring the thermal resistance value of a whole roof assembly under hot conditions due to the uncertainty of the outdoor environment. Currently, no established method exists to experimentally investigate an entire thermal roof performance under a steady-state condition. This article details the properties of the indoor solar simulator and the research methods undertaken to measure the thermal resistance value of roof assembly. The indoor solar simulator utilizes 40 halogen bulbs to accurately replicate sun radiation. Thermocouples and heat flux sensors are installed at several locations on the roof assembly to quantify the heat transmission occurring through it. The thermal resistance value is determined by adding up the average difference in temperature across the external and internal roof surfaces and dividing the total amount by the total of all averaged heat fluxes. Subsequently, this study investigates the thermal efficiency of residential roof assemblies that comprise various insulation materials frequently employed in Malaysia, including stone wool, mineral glass wool, reflective bubble foil insulation, and radiant barriers. The analysis showed that the roof configurations with bubble foil reflective insulation produce superior thermal resistance values when coupled with enclosed air space or mass insulation, with thermal resistance values ranging between 2.55 m2K/W and 3.22 m2K/W. It can be concluded that roof configurations with bubble foil reflective insulation resulted in high total thermal resistance and passed the minimum thermal resistance value of 2.5 m2K/W under the Malaysian Uniform Building By-Law 38 (A) requirements. Furthermore, the radiant barrier produced a high thermal resistance value of 2.50 m2K/W when installed parallel to a 50 mm enclosed air space, emphasising the crucial function of an enclosed air space next to a reflective foil to resist the incoming heat radiation. The findings from this research can help building professionals determine the optimum insulation for residential building roofs in Malaysia.

PV installations and the safety of residential buildings

The dynamic development of the photovoltaic industry entails threats that have a direct impact on the safety of residential buildings. Appropriate design of a PV installation can be a challenge due to the multifaceted nature of this issue. The designer should take into account issues related to the selection of electrical parameters of the installation, adapting lightning and surge protection in accordance with applicable standards, ensure the optimization of the system in terms of efficiency and fire safety and calculate the mechanical stress on the rooftop. Unfortunately, most PV installations in Poland are built without any engineering project, which is allowed by the current law. In this article, we describe the results of simulations of real mechanical loads inflicted from the installation of PV panels on flat roofs for various regions of Poland. We also present the results of the simulation of the thermal impact of hot-spots on the roof surface, which can be a potential source of fire. In addition, we propose changes to the regulations that may increase the safety of PV installations mounted on the roofs of residential buildings.

Parametric design of a residential building system through solar energy potential: the case of Guelma, Algeria

To evaluate the potential of retrofitting roofs of residential buildings in Algeria with building integrated photovoltaics (BIPV). A case study of a family residential building in the city of Guelma, was selected to receive building-integrated photovoltaic (BIPV) systems as a retrofit to their roofs using Rhinoceros software and plugins Grasshopper, Ladybug, and Honeybee, adding photovoltaic panels on the roof taking into account the study of solar radiation analysis on the building, and meteorological data from Meteonorm Software 7.3. The method used, is based on measured data for final energy consumption (yearly average of 14600 kWh), building morphology, and photovoltaic module parameters. The results of the renovation of roofs with building-integrated photovoltaic solutions are presented for the existing residential building, it is also shown that a small photovoltaic area on the roofs can meet the demand of the buildings. The results identify the aspects that need to be improved in the development of future design tools and highlight the importance of integrating parametric design software and simulation tools for BIPV systems at the preliminary design stage, to ensure good building performance, both in terms of comfort and energy performance.

Solar Hotspot Analysis using Image Processing in MATLAB

Abstract: Solar energy has proven to be an undisputed frontrunner among renewable energy sources: it is clean, environmentally responsible, and cost-effective. The utilization of solar energy as a sustainable and renewable source of power has gained significant attention in recent years. The rapid growth of solar farms and solar roofs of residential buildings has led to an increase in demand for solar modules in the global market. Therefore, the maintenance and monitoring of solar modules must rely on an effective technique for predicting and evaluating future performance. Solar hotspots, also known as solar irradiance anomalies, are areas on solar photovoltaic (PV) panels or arrays that experience excessive heating, resulting in decreased energy output and potential damage to the PV cells.

Computer-Aided Dynamic Evolution Analysis of Roof Decoration Art in Northern Jiangsu Based on Low-Frequency Remote Sensing Image Technology

In the application of remote sensing image fusion based on wavelet packet, the wavelet packet frequency shifting algorithm used to adjust the frequency sequence of wavelet packet decomposition is introduced to solve the frequency aliasing phenomenon caused by interval sampling. The roofs of ancient residential buildings in northern Jiangsu have a unique art. Features: Discusses the roof decoration art of residential buildings in northern Jiangsu, aiming to provide some references for modern architecture. It shows that the roofs of residential buildings are deeply influenced by the land culture and marine culture, and have both normative, delicate and exaggerated factors. . The roof ridge of the folk houses embodies the uniqueness and rich connotation of Nantong culture, and we need to actively explore the beneficial elements in it. By examining the overall trend of international computer-assisted language testing research, high-yielding countries, authors, institutions and high-cited journals, research hotspots and high-innovation literature.

Analiza kapaciteta za izgradnju fotonaponskih sistema na krovovima stambenih zgrada u Srbiji

The roofs of residential buildings represent a relevant potential for the construction of photovoltaic panels. Given that roof structures are passive, the construction of photovoltaic systems on residential buildings does not interfere with the functionality of the building, nor do they affect the environment in any other way. By installing photovoltaic systems on the roofs of residential buildings, the production and consumption of electricity are brought closer to the maximum possible extent, so such systems ensure a significant reduction of electricity losses in the distribution and transmission network. This paper presents the results of research aimed at establishing a framework for decentralized and decarbonized production of electricity from photovoltaic systems integrated into the roofs of residential buildings in Serbia, through the support of the prosumer approach. For each defined category of residential building in Serbia, the possible annual production of electricity per unit of average roof area was estimated. Summarizing all the results, assessments of the possible installed capacity of photovoltaic systems and annual electricity production at the national level were made.

Analyzing Wind Energy Potential Using Efficient Global Optimization: A Case Study for the City Gdańsk in Poland

Wind energy (WE), which is one of the renewable energy (RE) sources for generating electricity, has been making a significant contribution to obtaining clean and green energy in recent years. Fitting an appropriate statistical distribution to the wind speed (WS) data is crucial in analyzing and estimating WE potential. Once the best suitable statistical distribution for WS data is determined, WE potential and potential yield could be estimated with high accuracy. The main objective of this paper is to propose a novel approach for calculating wind energy potential. For this purpose, the Efficient Global Optimization (EGO) technique was proposed for fitting a statistical distribution to WS data and the performance of the technique was compared with genetic algorithm (GA), simulated annealing (SA), and differential evolution (DE). Performance metrics showed that EGO is providing better estimations compared with GA, SA, and DE. Based on Weibull parameters obtained by using EGO, potential WE and potential annual revenue were estimated for Gdańsk, which is the capital of Pomerania Voivodeship in Poland, in the case of having city-type wind turbines in the city center. Estimations for Gdańsk showed that city-type wind turbines might be helpful for producing electricity from WE in the city without being limited by constraints such as having a long distance between wind turbines and buildings. If such wind turbines were erected on the roofs of residential buildings, malls, or office buildings, there is a possibility that part of the electric energy needed for such buildings could be generated using WE. However, this topic should be further investigated from technical and financial perspectives.

Numerical simulation of airflow in naturally ventilated attics for different attic geometries

AbstractAttic geometry and ventilation in a different attic geometry play a very important role in residential building energy performance. To evaluate the effect of ventilation ratio and vent balance on attic performance, a two‐dimensional finite volume model is employed to simulate the buoyancy‐driven turbulent ventilation and heat transfer in an attic space of different geometries like gable, gambrel, and saltbox roofs of residential buildings under winter conditions. The impact of ventilation ratio on ventilating airflow rate, heating load rate, and rate of heat gained is investigated for all three types of roof geometries. The model under consideration consists of a passive ventilation system with a ridge and soffit vent. Meshing is done by using ANSYS Workbench and numerical simulations are carried out by using ANSYS FLUENT 19 analysis software. The effect of passive ventilation on ridge‐vent attic performance is evaluated in this study. Ventilation ratios for soffit vents ranging from 1/400 to 1/25 are investigated. Convection boundary conditions are used for the attic walls to account for thermal resistances of ceilings and roofs. In addition, the performance of these vented attics is compared to the heat transfer in a sealed attic. The results show that the symmetrical airflow pattern exists in a vented attic, in contrast to the asymmetrical airflow patterns found in a sealed attic. From the study, it is evident that an increase in ventilation ratio reduces attic heating load irrespective of the increase in ventilation airflow rate. The rate of airflow increases with an increase in ventilation ratio in all three types of roof geometries that is gable, gambrel, and saltbox roofs. In the case of gable roof configuration, increasing the ventilation ratio from 1/200 to 1/100 results in an increase in ventilating mass flow of 75%, while an increase of ventilation ratio from 1/50 to 1/25 only increases the ventilating mass flow by 40%. In the case of gable roofs increasing ventilation ratio from 1/200 to 1/100 results in a 20% decrease in attic heating, whereas an increase in ventilation ratio from 1/50 to 1/25 results in a 10% decrease in attic heating.

Roof-mounted photovoltaic generator temperatue modeling based on common brazil roofing materials

This paper examines the performance of solar photovoltaic generators on roofs of residential buildings. The primary focus is the loss of performance due to temperature increase as function of roof material and the distance from the photovoltaic (PV) generator to the roof. A heat transfer model has been developed to predict PV module temperature, and the equations of the model were solved using the Engineering Equation Solver (EES) software. The research modeling correlates the distance of the solar generator to the roof and the roofing material with the temperature variations in the PV generator. There are many models to predict PV module temperature, but this study refines the prediction by the distance from PV module to roof and the roofing material as variables. Optimal combinations of distance and materials that minimize the heating loss in the solar generator leading to increased electrical power generation. Results show an average error of 3%–4% from the temperature predicted by the model to the temperature measured under experimental conditions in Belo Horizonte, Brazil. The minimum roof-module separation required to ensure minimal PV performance loss from heating from the roof is ∼10 cm for red ceramic and cement fiber roofs. For galvanized steel, the optimal distance is between 20 cm and 30 cm. Cement fiber shows the best predicted and measured characteristics for PV-panel roof mounting among the 3-common commercial roofs evaluated in these studies. These investigations were based on roof installations and local materials in Belo Horizonte, Brazil.

إعادة تهيئة الأسطح القائمة کقيمة بيئية و اقتصادية مضافة دراسة حالة: عمارات العبور- مدينة القاهرة Retrofitting existing conventional roofs as an environmental and economic added value Case study: El Obour Buildings – Cairo City

Cairo faces many problems such as overpopulation and environmental pollution due to the lack of green spaces in it, with the lack of empty spaces suitable for cultivation. In view of the large spread of the existing residential buildings in central Cairo, a study was conducted on the feasibility of greening the existing roofs of residential buildings with one unity to retrofit the roofs of these buildings and make use of them from an environmental, economic and architectural point of view. El Obour residential buildings were chosen as an example of a populated group of buildings under the one association of the Union of Owners in order to ease the application of roof greening to them. In case of working on existing buildings, the type used in roof greening must be studied in terms of loads and the appropriate installation method for these roofs.

Forecasting the Energy and Economic Benefits of Photovoltaic Technology in China’s Rural Areas

In recent years, with the rapid development of China’s economy, China’s energy demand has also been growing rapidly. Promoting the use of renewable energy in China has become an urgent need. This study evaluates the potential of solar photovoltaic (PV) power generation on the roofs of residential buildings in rural areas of mainland China and calculates the area that can used for generating energy, the installed capacity, and the power generation, and conducts a comprehensive analysis of the economic benefits of investing in the construction of distributed PV systems in various provinces. The findings unveiled in this study indicate that China still has more than 6.4 billion m2 of rural construction area available for the installation of PV modules. If this is all used for solar power generation, the annual power generation can reach up to 1.55 times the electricity consumption of urban and rural residents for the whole society. Through a comprehensive evaluation of energy efficiency and economic benefits, the Chinese mainland can be divided into three types of resource areas. The three types of resource areas have their own advantages and disadvantages. According to their own characteristics and advantages, we can reasonably formulate relevant policies to accelerate the development of PV system application in rural areas.

Possibilities of Transition from Centralized Energy Systems to Distributed Energy Sources in Large Polish Cities

The main aim of this paper is to evaluate the possible transition routes from the existing centralized energy systems in Polish cities to modern low-emission distributed energy systems based on locally available energy sources, mainly solar energy. To evaluate these possibilities, this paper first presents the current structure of energy grids and heating networks in Polish cities. A basic review of energy consumption in the building sector is given, with emphasis on residential buildings. This paper deals with the evaluation of the effectiveness of operation of central district heating systems and heat distribution systems; predicts the improvement in the effectiveness of the energy production, distribution, and use; and analyzes the possible integration of the existing system with distributed energy sources. The possibility of the introduction of photovoltaic (PV) systems to reduce energy consumption by residential buildings in a big city (Warsaw) is analyzed. It is assumed that some residential buildings, selected because of their good solar insolation conditions, can be equipped with new PV installations. Electricity produced by the PV systems can be used on site and/or transferred to the grid. PV energy can be used not only for lighting and electrical appliances in homes but also to drive micro- and small-scale heat pumps. It is assumed that the PV modules are located on roofs of residential buildings and are treated as individual micro scale energy systems of installed capacity not larger than 50 kW for each of the buildings. In such a case, the micro energy system can use the grid as a virtual electricity store of 70% or 80% efficiency and can produce and transfer electricity using a net-metering scheme. The results show that the application of micro-scale PV systems would help residential buildings to be more energy efficient, reduce energy consumption based on fossil fuels significantly, and even if the grid cannot be used as a virtual electricity store then the direct self-consumption of buildings can reduce their energy consumption by 30% on average. Development of micro-scale PV systems seems to be one of the most efficient options for a quick transformation of the centralized energy system in large Polish cities to a distributed energy one based on individual renewable energy sources.

CNN BASED DETECTION OF BUILDING ROOFS FROM HIGH RESOLUTION SATELLITE IMAGES

Abstract. The detection and reconstruction of building have attracted more attention in the community of remote sensing and computer vision. Light detection and ranging (LiDAR) has been proved to be a good way to extract building roofs, while we have to face the problem of data shortage for most of the time. In this paper, we tried to extract the building roofs from very high resolution (VHR) images of Chinese satellite Gaofen-2 by employing convolutional neural network (CNN). It has been proved that the CNN is of a higher capability of recognizing detailed features which may not be classified out by object-based classification approach. Several major steps are concerned in this study, such as generation of training dataset, model training, image segmentation and building roofs recognition. First, urban objects such as trees, roads, squares and buildings were classified based on random forest algorithm by an object-oriented classification approach, the building regions were separated from other classes at the aid of visually interpretation and correction; Next, different types of building roofs mainly categorized by color and size information were trained using the trained CNN. Finally, the industrial and residential building roofs have been recognized individually and the results have been validated individually. The assessment results prove effectiveness of the proposed method with approximately 91% and 88% of quality rates in detection industrial and residential building roofs, respectively. Which means that the CNN approach is prospecting in detecting buildings with a very higher accuracy.

Использование комплексного подхода к определению надежности и остаточного ресурса деревянных конструкций жилых зданий

the article considers the problem of determining the reliability and residual life of roofs of residential buildings, taking into account an integrated approach, which includes determining the reliability of each element taking into account physical wear and tear and calculating the reliability of the “roof” system using graph theory.
 Five two-story residential buildings in the Ryazan region were selected as objects for evaluation: in the city of Skopin and in the city of Ryazan. When examining the roof structure, typical damage was revealed: the absence (including fragmentary) of the roof covering, biological damage to the wood by the bark beetle, rot, warping of the boards and others.
 To assess these damages in determining physical deterioration (by external signs), departmental standards were used, the reliability of roof structures as a system of interconnected elements was determined on the basis of graph theory.
 It has been established that the roofs of two of the five buildings have reached an inoperative state, and the residual life for the roofs of three buildings ranges from 1 to 14 years.

Rainwater harvesting in Jordan: potential water saving, optimal tank sizing and economic analysis

ABSTRACT This paper presents an integrated approach regarding rainwater harvesting that includes investigating potential water savings, optimal tank sizing and cost-benefit analysis at different rainfall zones in Jordan. It is found that a maximum of 30.5 × 106 m3/year of rainwater can be collected from the roofs of residential buildings which is approximately 8% of the total supply for the year 2015. In addition, water harvesting yields and optimal tank size are calculated for any roof area in different rainfall zones in Jordan. Benefit-cost analyses results revealed that pear shape tanks will be economically feasible in all rainfall zones when a 1 $US/m3 is assigned as a cost of water saving. Concrete tanks will not be economically feasible at this cost. Payback period analysis indicates that the costs associated with the installation of rainwater harvesting systems could be equalized within 5–45 years depending on the rainfall condition, roof size, price of water savings and tank type.

Techno-economic assessment of application of solar PV in building sector

Techno-economic assessment of application of solar PV in building sector

Thermal Analysis of Integrating Roof with Phase Change Materials for Energy Saving in Residential Buildings

The sector of air-conditioning in the residential building consumes most of the total ‎electricity supplied for heating or cooling. Thus it has a major impact on the greenhouse gases and climate. Phase change ‎materials (PCMs) are regarded as a possible solution for reducing the energy consumption of ‎buildings by storing the heat and releasing it in certain times. The present study assists for the ‎utilization of PCMs in the roof of residential building to absorb the heat comes from solar ‎radiation during the daytime and releasing it to the inside nightly. Building considerations ‎as well as thermo-physical properties of PCMs have been taken and measured experimentally. ‎Results have shown that these materials have a good potential for reducing energy demand ‎and satisfy comfortable thermal conditions. The obtained readings, from a rig model built for that purpose, ‎showed that the indoor temperature could increase by 5-9oC in the winter compared to that ‎measured in a traditional one. Furthermore, a simulation program depended on degree-days ‎method explained that the energy consumption could be saved up to 75%. Thus PCMs could ‎submit encouraging suggestions toward the sustainability.‎

Photocatalytic degradation of cooking fume on a TiO2-coated carbon nanotubes composite filter

A TiO2/MWCNTs/Al2O3/NF (TiO2 nanoparticles/multi-walled carbon nanotubes /Al2O3-modified nickel foams) composite filter was prepared through grown of MWCNTs upon Al2O3-modified nickel foams using chemical vapor deposition (CVD) method and then coated TiO2 nanoparticles onto MWCNTs using dip-coating method. The MWCNTs forms a network-like structure on the surface layer of composite filter. The BET surface area of TiO2/MWCNTs/Al2O3/NF composite filter is more than 375 times higher than that of the pristine nickel foam. The degradation performance of oil particles was evaluated. Under optimized reaction conditions, 90% of the oleic acid on the filter was decomposed after 25 h. In addition, the effect of reaction temperature and light intensity were studied. Increased reaction temperature and light intensity were found to significantly improve the degradation rate and restrain the formation of refractory product. Furthermore, a parallel reaction kinetic model was adopted for degradation of oleic acid on the composite filter. The composite filter can reduces the accumulation of oil particles on the filter and the energy consumption of the filter. This approach proposes a new way to treat the cooking fume emission at residential building roofs.

A life-cycle cost analysis for an optimum combination of cool coating and thermal insulation of residential building roofs in Tunisia

The interaction between the roof thermal insulation and the cool roof effects is assessed in order to determine an optimum combination of the two measures. Dynamic simulations and estimation of the annual energy requirements are performed using EnergyPlus. Two roof structures, three insulation materials and three reflectivity scenarios are considered while taking into account the ageing of the cool material. An energy-based optimization shows that the summertime benefits induced by the rise of reflectivity outweigh the winter penalties, and that the optimum value of the roof reflectivity is the highest possible value. Moderate roof insulation levels with cool roof surfaces of as high as possible reflectivity values are recommended in the Tunisian climate. A 20-year life-cycle cost analysis proves the cost-effectiveness of aged and restored cool roof scenarios for uninsulated roofs with a net saving up to 44.53 TND/m2 and a payback period of 3.4 years. In terms of maximum net savings and considering the environmental benefits of cool roofs, we recommend an optimum combination of the restored concrete-based roof and a 5.4 cm-rockwool thickness. A sensitivity analysis shows that the uncertainties in the economic parameters and changes in the set-point temperatures have a noticeable effect on the optimal parameters.