Today's Buildings Research Articles

Development of a vibration-damping, sound-insulating, and heat-insulating porous sphere foam system and its application in green buildings

With the development of green buildings, people pay more attention to the quality of the indoor sound environment. The air sound insulation performance of floors and exterior walls plays a key role in today's green buildings. The thermal performance of the enclosure structure's floor and exterior wall heat transfer resistance is an important factor in reducing building carbon emissions in green buildings. The aim of this paper is to study the efficiency of the acoustic and thermal insulation of a foaming system with porous carbon balls and the combination of different structural ways of construction boards and external walls. The acoustic and thermal parameters of different sound insulation and thermal insulation systems designed with porous carbon sphere foam and inserted into the floors and exterior walls are compared to highlight the optimal structure. The theoretical and experimental tests showed that to improve the sound insulation performance of the floor, a sound insulation system needs to be placed on the surface of the floor in contact with the impact object and inlaid in the vertical gap in contact with the floor and the wall. Furthermore, it has been determined that the surface of the foam particle acoustic ball with micropores has good sound absorption performance. Finally, the high-quality building thermal insulation material with low thermal conductivity in any combination with the floor slabs and the external wall structure improves the thermal insulation performance.

Reconfigurable supply-based feedback control for enhanced energy flexibility of air-conditioning systems facilitating grid-interactive buildings

Air-conditioning systems have great potential to provide energy flexibility services to the power grids of high-renewable penetration, due to their high power consumption and inherent energy flexibilities. Direct load control by switching off some operating chillers is the simplest and effective means for air-conditioning systems in buildings to respond to urgent power reduction requests of power grids. However, the implementation of this approach in today's buildings, which widely adopt demand-based feedback controls, would result in serious problems including disordered cooling distribution and likely extra energy consumption. This study, therefore, proposes a reconfigurable control strategy to address these problems. This strategy consists of supply-based feedback control, incorporated with the conventional demand-based feedback control, a control loop reconfiguration scheme and a setpoint reset scheme, facilitating effective control under limited cooling supply and smooth transition between supply-based and demand-based feedback control modes. The proposed control strategy is deployed in a commonly-used digital controller to conduct hardware-in-the-loop control tests on an air-conditioning system involving six AHUs. Test results show that the reconfigurable control achieves commendable control performance. Proper chilled water distribution enables even thermal comfort control among the building zones during demand response and rebound periods. Temperature deviation of the building zones is controlled below 0.2 K most of the time. 11.6 % and 27 % of power demand reductions are achieved during demand response and rebound periods respectively, using the proposed reconfigurable control compared with that using conventional controls.

Blockchain-based fire safety inspection analysis and system design

Today's buildings usually rely on various firefighting equipment for warning, often neglecting the importance of safety inspections. Most fires occur due to the usual weak awareness of fire prevention. If regular and strict safety inspections are carried out according to the regulations of fire departments will greatly reduce the occurrence of fires. Safety inspections in each unit include fire supervisors from the government and inspectors from relevant maintenance agencies, and these inspectors usually use paper reports to record the safety inspection work. This traditional practice leaves hidden problems for unresolved and important issues, including data integrity and tamperability, which will directly lead to difficulties in tracing responsibilities based on these data after an accident. Therefore, this paper proposes a de-neutralized, blockchain-based traceability system for a fire safety inspection. Blockchain technology has the characteristics of traceability, decentralization, consensus trust, and hard to tamper, which can be combined with this system. The system's core mainly adopts the Hyperledger Fabric consortium blockchain framework, configured to build a blockchain network. The network is organized with three organizations: government, unit, and maintenance agency, and smart contracts are written to process safety inspection data, thus guaranteeing the sharing of fire inspection information as well as traceability.

Thermal environment evaluation and thermal comfort zone deviation ——a case study of Chinese seaweed house in summer

Renewing the vitality of traditional ecological dwellings in the context of global carbon peaking and carbon neutrality targets has become one of the important topics in today's building sustainability research, and the evaluation of thermal comfort in traditional dwellings is the key to it. In this paper, one of the most representative ecological dwellings in the world, the “Seaweed House”, was selected as the research object. Firstly, the physical environment of a seaweed house in Dazhuang Xujia Village was measured from July 29 to August 3, 2022. Secondly, a thermal comfort questionnaire was conducted to grasp the current information of the thermal comfort in seaweed house. The results show that:1. The humidity of seaweed houses in summer is too high. 2. Residents have a thermally neutral temperature of 26.9 °C, an acceptable temperature region of (24.8–29.1 °C), and a thermally desired temperature of 25.8 °C. 3. The adaptive predicted mean vote (APMV) model suitable for thermal comfort evaluation of seaweed houses was developed. The results of the study provide a precise theoretical guide for the study of thermal comfort evaluation models in this region, and a useful reference for the study of the renewal and renovation of the seaweed houses.

Building Production Processes Planning and Management in Classical Greek Era; Comparison with Contemporary Practices

Through the example of the Classical Greek Era, the study focuses on seeking an answer to the question of whether managerial techniques and strategies were developed in building production processes in ancient times. The study aims to identify and examine the stages planned in the building production processes and the construction management and organization techniques developed during the Classical Greek period (VI.-IV. century BCE), which played an important role in the development of building art and to compare the practices of the Era with today's construction and management practices. The research methodology is based on the interpretation of historical data from the Classical Greek Era, consisting of construction texts written on stone slabs and their epigraphic explanations, and the comparison of the practices of the Era with contemporary practices. The stone slab samples with the construction texts used in the study were taken from the Sara B. Aleshire Center for Greek Epigraphic Studies catalogs at the University of Berkeley. The epigraphically analyzed descriptions of these inscriptions by different authors were obtained by searching the literature sources through the catalog numbers given to the samples. In the classical Greek Era, three main administrative public bodies made decisions on construction, planning, and managing the construction processes. These include the Senate, Ecclesia (people's assembly), and building commissions. By the decision of the people's assembly, building commissions were established to manage and supervise the construction process from a financial, administrative, and technical perspective. This research has contributed to the understanding that today's building production strategies and management theories have their roots in ancient times, thereby contributing to the universality of construction and management theory. Due to the dynamic nature of the research, the period analyzed was also compared with the current production management theories. The study's uniqueness lies in interpreting historical documents and observing and comparing current conditions. Hence, while the construction and management systems in the Classical Greek period are understood, two different processes are analyzed in their own contexts, and their differences and similarities are highlighted.

Electric-impulse-technology: results of a basic investigation into the use of the technology as a selective demolition method in the construction industry

A large proportion of today's building projects are realized in existing buildings. This almost always requires the sensitive deconstruction of existing building fabric. Deconstruction technologies have to fulfill high requirements particularly in inner-city residential areas and during ongoing building use, both for construction projects in the existing building stock and for new construction activities. Currently used demolition technologies rarely meet the growing requirements in building practice. Common demolition and separation methods are characterized by high emissions, such as vibrations and noise, large quantities of blasting material, slow performance progress or high physical effort. An alternative technology is the electrodynamic Electric-Impulse-Technology (EIT). The process technology, initially developed for applications in mining and special civil engineering, is based on the destruction of solid materials by high-voltage pulses. On the basis of large-scale tests in mining dimensions, it was possible to demonstrate high dissolving capacities with low energy input. The research project aimed to investigate the basics for transferring the EIT to low-emission and selective material removal in civil and structural engineering. Extensive laboratory tests were conducted on sand-lime and concrete specimens to verify the adaptation of the EIT. It was found out that the technology is suitable for use in the construction industry. Further research is to be conducted to investigate the identified areas of application in greater depth and to further develop EIT for practical use.

Heat recovery ventilation design limitations due to LHC for different ventilation strategies in ZEB

Today's buildings are becoming more insulated and airtight to reduce transmission heat losses. Energy use for ventilation can represent up to half of these buildings' total energy use. Heat recovery in ventilation and demand-controlled ventilation (DCV) are energy-efficient measures to reduce ventilation energy use, especially when combined. However, this study revealed that the often-overlooked longitudinal heat conduction (LHC) in aluminium rotary heat exchangers might yield less efficient heat exchangers, particularly for intended high-efficiency heat recovery at low ventilation rates in DCV. This study presents a theoretical method to assess the effect of LHC on the amount of energy used to heat ventilation air for several ventilation strategies. The method is demonstrated in a case study for a virtual office building in a cold climate (Oslo, Norway). When neglecting the LHC effect, the energy used to heat the supplied air using DCV with a rotary heat exchanger is about three times smaller than when considering LHC. Unlike earlier studies, we find that DCV may consume more ventilation heating energy than constant air volume (CAV) ventilation when the selected wheel is deep and oversized due to LHC. This study highlights the need to design rotary heat exchangers carefully in order to account for the LHC effect, particularly when targeting zero emission buildings (ZEB).

Structural optimization of four designed roof modules: Inspired by Voronax grid shell structures

Architects have been following nature in their constructions for a long time. Observations of nature reveal that it has many highly developed structures that provide scientists and engineers with a lot of useful clues for creating more efficient structures and building forms. Therefore, revealing systematic thinking about natural species is a crucial requirement for today's buildings. A software analysis method was used to design four modules in the roof structure of the Iranian University of Science and Technology's exhibition. The roof structure is based on the Voronax structure, which is a relaxed form of Voronoi, which is seen in the structures of many natural creatures. They were analyzed in terms of optimization and structural simulation using Grasshopper plugins and tools by taking into account Von Mises stress in the structural design. The results indicated that by increasing the density of Voronax cells in the areas with high Von Mises stress concentration, a more efficient structure could be achieved in terms of load-bearing and designing predefined free-form roof structures. By analyzing predefined roof structures in an optimum way, the study took a step toward optimizing these kinds of structures.

Investigation of the effects of mechanical and underfloor heating systems on the COVID-19 viruses distribution.

Investigation of the spread of pollutants and especially pathogenic particles in the interior of today's buildings has become an integral part of the design of such buildings. When the Coronavirus is prevalent in the world, it is necessary to pay attention to the spread of the virus in the interior of residential apartments. In the present study, the Coronavirus particles emitted from the sneezing of a sick person in the bedroom of a residential apartment were tracked. Meanwhile, the degree of exposure of a mannequin that has been placed in the living room playing the role of a healthy person is examined. In this research, a segregated solution of steady-state flow and an unsteady particle solution have been separately used: a suitable, accurate, and optimal solution in particle studies. A comparison of the results shows that underfloor heating creates a healthier space around the healthy person's respiratory system, but instead, we will see more polluted areas around the sick person. According to the PRE results, the PRE value for a mechanical heating system is higher than a floor heating system. Therefore, it is recommended to use mechanical heating system in the apartments where the person with COVID-19 is hospitalized.

Simulation the effectiveness of heat recovery of the regenerative ventilator using different approaches

Today buildings should be designed for energy efficiency class not less than C. This requires ventilation with heat recovery. On the market, there are different compact heat recovery ventilation units for decentralized ventilation. Regenerative ventilators represent a promising area of effective ventilation with exhaust air heat recovery. They operate cyclically for the inlet and outlet of air. These kinds of ventilators should work in a blocked pair(s) – one for input and one for output in each pair. If not, the effectiveness will decrease. A mathematical model of the ceramic heat regenerator in the regenerative ventilator “Twin Fresh” by Vents has been created to improve the efficiency of its operation. In previous works, on the basis of two different approaches, the operation of the heat regenerator was simulated. The first one uses M. Mikheev’s formula for the Nusselt number. The second one is computational fluid dynamic simulation by SolidWorks Flow Simulation. The efficiency coefficients obtained as a result of the simulation had a significant difference – up to 66.5 %. The aim of the work is to find alternative methods for adequately determining the efficiency of the ventilator. A mathematical simulation was performed using a different formula from “Novyi spravochnik khimika i tekhnologa. Protsessy i aparaty khimicheskikh tekhnologii”. This formula takes into account the Grashof number. Values obtained are significantly different from both previous ones – up to two times. There is no information in the literature about the experimental conditions for determining the Nusselt number, which was used in the simulation. Therefore, we can’t assume, what approach is closer to the conditions of the ceramic regenerator. There is a need to conduct experimental studies to determine the efficiency of the regenerative heat exchanger.

An Optimal Model for Designing and Executing Windows in Tabriz Residential Buildings to Reduce Energy Consumption

Most of today's buildings, due to improper imitation of the architecture of buildings in other countries, are forced to use more energy to create conditions of thermal comfort. Building windows affect energy efficiency. So, the aim of this research is to be concerned with Tabriz climate; in selecting the proportion and suitable glazing of the windows, in order to access the best design and execute a model to decrease energy consumption. The research approach is to utilize simulation and Design Builder software as a research tool. So, the annual gas consumed in the Building was received from the National Iranian Gas Company and a case study is modeled and after converting the unit from kWh to kg and kg to m3 and reliability of simulation results. Then, through parametric optimization, eight scenarios in designing windows and through the genetic algorithm, the glazing coating were evaluated. The simulations were performed again and the results index was examined. Eventually, based on the analysis of outputs, according to fixed area, it is more suitable to replace windows with the height of 1.5 to 1.74 meters instead of windows with the height of 1 or 1.2 meters. A window should be replaced with 2, 3, 4 or 5 windows with the same fixed area. I is desired to superseded triple-glazed glazing with low-emissivity filled with argon gas with clear double-glazed glazing filled with air to reduce energy consumption. The amount of heat losses for the window height of 1 to 1.5m, from one window to five windows and for the clear double-glazed glazing filled with air were 2.04%, 11.11%,. and 45.36%, respectively.

Indoor Air Pollution in Housing Units

Pollution and poor quality of the indoor environment is a common problem in today's residential buildings. These problems are reflected in the well-being and health of the users of these buildings. Targeted identification of the various harmful substances (pollutants) is essential for understanding the interactions of components of the internal environment for the welfare and health of building users. The Czech housing units were selected for screening investigation of indoor air quality. Measuring of indoor chemical factors was performed during the year 2019. The indoor levels of TVOC, nitrogen oxides, indoor radon, and particulate matters PM10 were measured. The results provide introduce data on indoor air quality concerning seasonal changes which were in correlation to air change rate. These results, introduced in this paper, help to understand the indoor pollutants occurrence and help to design next more focused studies.

GIẢI PHÁP NÂNG CAO HIỆU QUẢ HOẠT ĐỘNG CỦA CÁC TỔ TIẾT KIỆM VÀ VAY VỐN HƯỚNG ĐẾN PHÁT TRIỂN CỘNG ĐỒNG BỀN VỮNG

In today's community development, capacity building and community capital developing through social-welfare programs and policies is prioritized for integrated implementation for building the self-help community. Especially the important role of voluntary groups in the community towards sustainable development. With the sample of 356 VSLA members, the survey results have brought out the solutions for improving the microfinance activities via VSLA model such as promoting the role of financial and financial management service providers; improving the role of commune-level in-charged officers and group leaders; enhancing the quality of VSLA’s activities; and developing VSLA members’ skills and capacities. These are important solutions to build community capacity and mobilize people's voluntary participation in activities that would help develop the community sustainably.

Gare du Nord: The Cinematic Glass Cage of Modern Industrialization and Anxiety

In the air-flooded stairs of the Eiffel Tower, better yet, in the steel limbs of a pont transbordeur, we confront the basic aesthetic of today's building: through the delicate iron net suspended in midair stream things, ships and, sea, houses, masts, landscape, and harbor. The lose their delimited form: as one descends, they circle into each other and intermingle simultaneously .

Enabling 3D Ambient Light Positioning with Mobile Phones and Battery-Free Chips

Visible Light Positioning (VLP) has attracted much research effort recently. Most existing VLP approaches require special designed light or receiver, collecting light information or strict user operation (e.g., horizontally holding the mobile phone). This incurs a high deployment, maintenance and usage cost. We present RainbowLight, a low-cost ambient light 3D localization approach that is easy to deploy in today's buildings. Our key finding is that light through a chip of polarizer and birefringence material produces specific interference and light spectrum at different directions to the chip. We derive a model to characterize the relation for direction, light interference, and spectrum. Exploiting the model, RainbowLight calculates the direction to a chip after taking a photo containing the chip. With multiple chips, RainbowLight designs a direction intersection based method to derive the location. We implement RainbowLight and extensively evaluate its performance in various environments. The evaluation results show that RainbowLight achieves an average localization error of 3.3 cm in 2D and 9.6 cm in 3D for light on, and an error of 7.4 cm in 2D and 20.5 cm in 3D for light off scenario in the daytime.

Feasibility study for the use of variable air volume systems for office buildings

The main factor contributing to greenhouse gas emissions is the building up of the surrounding area. Studies have shown that buildings globally consume 30-40 % of energy use and release 40-50 % of global carbon dioxide emissions. Among all systems in houses, heating, ventilation and air conditioning (HVAC) systems are by far the most energy intensive. They consume approximately 50 % of the total energy demand of buildings. However, the systems are some of the most important systems in today's buildings. The number of these systems that are being installed has increased dramatically over the past few years. This is mainly due to the increasing demands for thermal energy, comfort and climate change. This paper presents a feasibility and ecology study between two ventilation or air-conditioning systems: constant air volume (CAV) and variable air volume (VAV). One of the purposes of this work is to determine the energy costs for each of the systems. An air conditioning system that saves operating costs usually requires a large initial investment. In this case, engineers must decide whether it is worth paying the additional upfront costs for a system that has lower operating costs. Despite the low attractiveness from the point of view of the investor, the VAV systems reduce the amount of greenhouse gas emissions and the amount of energy resources for servicing the commercial sector. Such system have less metal consumption. Thus, the cost of metal processing is also reduced. The results of this study can contribute to the future selection of ventilation systems, as well as contribute to the design and improvement of the systems under study. Energy saving is one of the main reasons why VAV systems are very popular today for the design of ventilation and air conditioning systems for office buildings and in many industries abroad. With these systems, the volume of transported air is reduced as soon as the operating load falls below the maximum projected load. The calculation of emissions of harmful substances into the environment was made while ensuring the operation of CAV and VAV systems.

Can we learn from heritage buildings to achieve nearly zero energy building and thermal comfort? A case study in a hot climate

ABSTRACT Heritage buildings were built in a period when energy equipment for cooling and heating did not exist. This research focuses on the way in which we could benefit from such constructions to impact today's buildings and society. The investigation will consider a number of elements such as thermal mass, day-lighting and thermal comfort in comparison with a new simulated building which has the same design as the Heritage one. The research was conducted using the energy simulation tool TAS EDSL and on site measurement. In addition to that, an advanced thermal imaging camera was used in the study of physical characteristics of the building. The study revealed that applying methods of Heritage buildings to modern buildings, such as the use of thermal mass and natural ventilation, can have a considerable impact on energy consumption and thermal comfort for users. It can reduce indoor temperature up to 5°C. It was also found that the use of natural ventilation is linked to indoor thermal comfort. Large area of glazing is recommended to be used in such region when it is applied in the proper way.

Possibility of Using Microwave Radiation for Rehabilitation of Historical Masonry Constructions

In the last years, there has been a growing demand for renovations and redevelopment of older buildings that do not meet today's building standards. A very common problem is the insufficient, damaged or completely missing waterproofing of buildings, which leads to water (or moisture) penetration into the structure of the building, but there are several possibilities to disseminate moisture into structures. Many rehabilitation methods require mechanical intervention into the structure of the building, but we mustn’t forget the structures where these procedures cannot be used, specifically objects with a rich historical value, that are protected by the National Heritage Institute.This article is focused on suitability, functionality and possibilities of using a non-destructive method of drying historic masonry with microwave radiation. First the method of microwave drying is described in general, then its use in construction practice is explained. Following is a description of the experimental work carried out at the Faculty of Civil Engineering. Outcome of this work is comparison of effects of microwave drying on samples of masonry containing three different types of building materials. One of these samples is made of brick construction, which has reached the age of 350 years. At the end, the results of the experiment and the consequent suggested recommendations are summarized.

Sarooj mortar: From a traditional building material to an engineered pozzolan -mechanical and thermal properties study

Developing new energy efficient building materials to reduce the carbon footprint is now the core of sustainability in construction and an essential factor of life cycle assessment (LCA). The extensive and increasing usage of conventional concrete, mortar, plasters and various cement-based materials is only one of the many factors contributing towards urban thermal discomfort caused by urban heat island phenomena and the poor thermal insulation of ordinary cement mortar. Not only this, the wide use of concrete and mortar in construction increases the consumption of their primary components mainly -Portland cement-requiring a large consumption of energy and causing a significant rise in CO2 emissions.Embedding natural and artificial cementitious/pozzolana materials in today's cement-based building materials has become a common practice. Cementitious and Pozzolanic materials are known to provide an added value to mortar/concrete not only in terms of mechanical and durability properties but also in energy efficiency and enhancing sustainability. Sarooj is a local term describing an artificial cementitious and pozzolana material obtained by traditional calcining of the raw clayey soil. Although its usage is nowadays very limited, Sarooj has been used in Oman and other neighboring countries for centuries, in various buildings and defense structures. The main objective of this research is to transform the traditionally produced Sarooj into an engineered binding material and hence investigating its physico-mechanical and thermal properties. The raw soil used to produce the traditional Sarooj was employed to engineer a modern “Sarooj” under controlled energy processing (grinding and calcination) conditions. The raw clay minded from specific location was ground first to a fine powdered material and then subjected to full characterization. The physical and chemical characterization indicated that the raw soil is suitable for producing a cementitious/pozzolanic calcined clay. The thermogravimetric and differential thermal analysis of the clay used reveal that only a moderate temperature of around 800 °C is required for its calcination which preserves energy and reduces CO2 emissions compared to 1600 °C to produce clinker cement. The strength development showed a slow early-age reactivity but an appreciable enhancement in long-term which demonstrates a remarkable latent hydraulic potential of the clay used. It was also found that adding an optimum amount of the calcined clay enhances the thermal properties. The annual energy performance of a typical housing in the hot climate of Muscat, Oman, was evaluated using DesignBuilder software, a whole-building simulation tool. The simulation results showed insignificant savings in annual energy consumption when the developed mixes are used as plastering materials. The clay alkali-activated with NaOH has, however, showed great potential to enhance the mortar's long-term strength. Using locally engineered cementitious material in a partial replacement of Portland cement can further enhance durability and sustainability by reducing the manufacturing energy of the produced building material such as mortars and plasters.

The School-building Model of the Church Schools in Nanjing, China before the 20th Century——Taking the Huiwen Academy as an Example

Church school is a special type of school in old China. After the first Opium War, Western churches have come to China to preach. Missionaries open churches, schools, and hospitals in China. This paper selects the largest church school in Nanjing in the late Qing Dynasty(before 1911) as an example. Based on the historical data of archival materials and the research methods of on-site mapping, the initial campus construction model of Nanjing Church School is summarized. The article first introduces the background of the school in China, the reasons for the establishment of the school, the history of the school; then analyzes the location, construction process, campus planning and architectural characteristics of the school; further analyzes the reasons why the western church replicates the western campus construction model; Finally, through the development of educational buildings, the contributions of church schools in the history of modern education in China are summarized. The article shows the development of large-scale educational buildings that are rare in the history of modern Chinese education. It not only clearly clarifies the history of the development of church schools in China, but also has important guiding significance for the heritage protection of today's historical buildings. At the same time, it also has important reference value for the protection of educational building heritage and campus construction in China and even in the world.