Buildings, Volume 8, Issue 6 (June 2018) – 9 articles

In traditional buildings many climatic strategies have been used to provide indoor thermal comfort in south and central parts of Iran. A common element is called an iwan. This study investigates the indoor thermal comfort of a room adjoined to a talar in a traditional house which has an iwan, in Shiraz, Iran. The data related to the temperature and relative humidity of the room are used to calculate the thermal comfort index of PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) by considering the following two cases: a talar room with an iwan and one without an iwan, by means of DesignBuilder software. For the purpose of validation, the air temperature and relative humidity of the talar room with an iwan were measured over 10 days and compared to the results of the simulation. Having a valid simulation, computation was conducted for the selected house in various cases for an annual passive operation of calculating PMV and PPD. The numerical results revealed that the talar room adjoined to an iwan located in the south front of the courtyard had relatively good conditions during the hot months, including June and July. In addition, it could provide fully satisfactory comfort conditions during August and September. According to the results, it is found that the iwan makes a talar room 62% more desirable for the hot months in comparison with a talar room without an iwan. Full article

In the contemporary construction management, poor project performance, cost overrun, and low-quality construction have become a central point of attention for improving project performance including information, interaction and communication management. Virtual design and building information modeling play indispensable role in improving the project performance. The aim of this study is to investigate the benefits and challenges of Virtual Information Modeling as a novel information and communication technology method on project management knowledge areas in the construction industry. Using one-sample T test with Kolmogorov-Smirnov approach, we analyzed data collected from structured questionnaire survey involving project managers working at architecture, engineering and construction industries in Tehran, Iran. The results with 64% response rate suggest that the most important benefits and challenges of using Virtual Information Modeling are related to the area of integration, and implementation of Virtual Information Modeling has significant impact on project integration management knowledge in compare with other project management knowledge areas. Thus, integration should be considered a top priority for construction companies implementing Virtual Information Modeling in their projects. Policymakers should understand that careful management of virtual information is essential for improving the performance of projects and enhancing the process efficiency. Full article

Demand-driven HVAC (heating, ventilation, and air conditioning) operation is essential in occupant-oriented smart buildings, where the levels of heating, cooling, and ventilation are intelligently regulated to avoid energy waste. Despite the great potential of building energy efficiency, one of the remaining technical challenges is how to accurately estimate building occupancy information in real time. In this paper, this design challenge is addressed. An advanced audio-processing technique is adopted that minimizes the impacts of environmental sounds on the recorded voice sounds of humans. Adopted mathematical modeling and signal processing procedures are elaborated in this work. Experimental studies show that our proposed audio processing with background sound cancellation algorithm improves the estimation accuracy of room occupancy quantity by approximately 11–12%, which results in an averaged ventilation energy reduction of 3.54% compared to the case of not applying background sound cancellation. The proposed audio-processing technique is promising to achieve non-intrusive, cost-effective, robust, and accurate solutions for building occupancy estimation. Full article

Modern renewable energy has been hailed as one of the prerequisites for fostering green growth and the achievement of sustainable development. Despite efforts to promote the use of renewable energy in households, its adoption has remained fairly low, hence the need for an inquiry into household capabilities needed for the acquisition and adoption of renewable energy technologies. This paper reviews the requisite capacities of households for the adoption of renewable energy services and expounds on some of the barriers hampering renewable energy among households. It takes a desk research approach to analyse the capacities which should be possessed by Zambian households and possible barriers constraining the widespread deployment of renewable energy technologies. The findings reveal that there is a need for a broader, multidimensional understanding of access to renewable energy in order for deployment to be effective. Barriers to the successful adoption of clean energy technologies include underserved populations, policy inadequacies; an underexploited renewable energy sector and heavy reliance on a service-challenged hydro-power utility. Since most of the aforementioned challenges are institutional in nature, the paper concludes with a recommendation of a baseline assessment to understand knowledge, perceptions, attitudes and drivers for renewable energy technology adoption among households. Full article

Most people do not use heating systems during nocturnal sleep in their bedrooms during the cold season in Japan; instead, they like to use extra blankets and quilts for sleeping. To investigate the effect of low air temperature (Ta) on sleep and thermoregulation when sleeping with bedding, 12 healthy young men participated in sleep experiments over three non-consecutive nights. The experimental conditions were at a Ta of 3 °C, 10 °C and 17 °C, with a relative humidity (Rh) of 50% and an air velocity of <0.2 m/s in the climatic chambers. The 4.3-clo bedding consisted of cotton sheets, an acrylic blanket, a down-filled quilt and a futon mattress. The average sleep efficiency index (SEI) remained >94% for each of the three Tas, and no disturbances were found by Ta in the sleep parameters, although the duration of rapid eye movement (REM) sleep showed variations at 3 °C. The skin temperature (Ts) of the forehead decreased in proportion to Ta and remained stable. The decreasing rate in rectal temperature (Tre), Ts of forehead and thigh during sleep were significantly greater at 3 °C than at 10 °C and 17 °C. The innermost microclimate temperature (Tmicro) made by the bedding did not correlate with the Tre. The young men were significantly more dissatisfied with 3 °C in the sleep quality evaluation. Full article

Building form and facade development for energy saving and generation are of great importance. Further development for natural ventilation purposes is also imperative as it is related to many issues that affect the quality of the living and working environment inside and around the buildings in outdoor and semi-outdoor spaces. In rapidly developing regions experiencing a warm and humid climate, like Saudi Arabia, mechanical cooling and ventilation are commonly used in residential and non-residential buildings. However, this was not the case in traditional structures, like the massive coral buildings of Jeddah, where cooling essentially depended on cross ventilation and heat storage in thermal mass. Further, the building forms in the traditional oriental city were optimized for natural ventilation on the macro- and micro-urban and room scales, respectively. Owing to the advancement in air-conditioning technology, conventional building design approaches tend to encourage sealed indoor spaces that rarely interact with the outdoor environment. Even in such harsh climates, during many months in a year, the outdoor temperature is remarkably low, allowing the utilization of natural ventilation within the rooms, as well as between building complexes and the surrounding spaces. This optimization process requires the integrated planning of many aspects, such as the facade, building form, as well as the intermediate threshold spaces between the indoor and outdoor spaces. Non-residential buildings in Saudi Arabia require a large amount of energy for operation. This is mainly due to the relatively high cooling demand caused by internal loads. A hybrid cooling system that incorporates mechanical and natural cooling and ventilation can be implemented for low-temperature days and nights. This paper presents a method for saving energy in a university faculty building, which is located in Jeddah. Models of the proposed solutions were analyzed using a computational fluid dynamics simulation tools, as well as the dynamic building simulation tool IDA-Indoor Climate and Energy (IDA-ICE) to assess user comfort and the level of reduction in energy demand. Full article

Due to the complexity, high-risk and conservative character of construction companies, advanced digital technologies do not become widely adopted in the short term, while vendors make determined efforts to overcome this and disseminate their technologies. This paper presents the methods of an investigation addressing the extremely complex issues related to the current practices of digital technology adoption in construction. It discusses how construction companies follow a specific logical process linked to need, project objectives, the characteristics of the adopting organization and the characteristics of the new technology to be adopted. The study aims to demonstrate a novel method of data collection and analysis, such as data and methodological triangulation techniques, including the use of NVivo and AHP to explore how companies make the decision to uptake new technology (e.g., advanced crane, tunnel boring machine or drones) by focusing on customer and vendor activities, their interactions, contributing factors and people involved in the process. The major original contribution of this paper is developing an innovative methodological cube for investigating the Construction Technology Adoption Process (CTAP) covering technology adoption, acceptance, diffusion and implementation concepts. CTAP is a framework that delineates the phases of the process that customer organizations use when deciding to adopt a new digital technology and the parallel vendor activities. The significance of these contributions is that they enable vendors to understand how to match their strategies with customer expectations in each phase of CTAP. It also provides a benchmark for new construction companies to use the current best practices of decision making. Future research is warranted to more clearly delineate any differences with respect to developing nations or related industries such as mining and property management. Full article

This paper presents an approach developed for selecting lighting systems in residential buildings using an Analytic Hierarchy Process (AHP) and the Multi Criteria Decision Making Technique (MCDMT). The developed approach considers four selection criteria of lighting systems: life-cycle cost, illumination, environmental performance, and life-span. The criteria of selection, along with the most widely used lighting systems in residential buildings, were determined through questionnaire surveys with suppliers, maintenance managers, and lighting experts. The Analytic Hierarchy Process and Multi Attribute Utility Theory were utilized to assess the significant influence of the identified main and sub-criteria on the selection process, from the design point of view. The developed approach was tested on a real case project in selecting the lighting system for aresidential building in Saudi Arabia. The obtained results show that the life-cycle cost and illumination proprieties, followed by the service life were found to be the most influential measures in the selection process. The results also show that Light-Emitting Diode(LED) lighting systems prove to bear the highest initial cost while sustaining the best overall performance. Full article