Analysis of the potential use of Trombe walls in Brazil: design recommendations

In this paper, the thermal performance of a standard environment was evaluated based on the use of a Trombe wall with different configurations and types of use, as the potential for using this passive strategy is still little studied in Brazil. This device is capable of absorbing energy from solar radiation by heating the air in this greenhouse and this heated air can be directed to the interior or exterior of the building depending on the purpose. This air can be used to heat the room or cool it by means of natural ventilation. The analysis of this research was based on a series of computer simulations using the EnergyPlus software, version 7.0 in order to quantify and classify the thermal performance of a standard environment equipped with this component, under the various construction configurations. Both for heating and cooling environments. The use of Trombe walls improved the thermal comfort of users in buildings located in Brazil, depending on the climate where they are located, promoting natural ventilation and passive solar heating, allowing the potential of this device to be investigated in the most diverse Brazilian regions.

Seasonal variations in indoor air quality parameters and occupants self-reported physical health within a warm humid climatic environment

This study examines seasonal variations in Indoor Air Quality in occupied spaces within student hostels of Obafemi Awolowo University, Nigeria, and the associated physical health effects reported by occupants. Indoor Air Quality data were obtained from 22 selected rooms, with at least two rooms selected from the nine different spatial design layouts identified in the hostel buildings. Indoor Air Quality parameters obtained were 15-minute interval data of relative humidity, as well as concentrations of carbon dioxide, total volatile organic compounds, and particulate matters. These were measured with data loggers placed at 1.0 m from the floor level in the centre of selected rooms. Measurements were taken in selected rooms through a period of four consecutive weeks each during the peaks of dry and wet seasons. A questionnaire, which was administered immediately at the end of the measurement period to 696 respondents, was used to capture the significant physical health symptoms as reported by the occupants, as well as information regarding their activities and use of the rooms. Significant health symptoms reported by occupants were the same across seasons. These were cold, fatigue, and headache. Indoor concentrations of carbon dioxide and particulate matters have most significant relationship with reported health symptoms.

Briefing: task force for climate financial disclosures (TCFD) for the property and construction industry

The property and construction industry are known to be a main contributor to climate change contributing more than 40% of the world's emissions. In direct response to this, there has been a call for corporations to be more transparent and align themselves to the requirements of the task force for climate financial disclosures (TCFD). This paper seeks to provide a briefing on the requirements of the TCFD. It highlights common challenges faced by the property and construction industry in implementing TCFD such as the difficulty in integrating climate related risks and translating them into quantitative measures, lack of capability within the industry to understand the complexities of climate risks and data collection issues among others. Recommendations are proposed to address these issues including setting up an industry specific network to share best practices in TCFD, harmonisation of existing frameworks to include TCFD requirements and exploring opportunities for incentivisation and rewards for early movers. This paper will be useful to property and construction industry practitioners who are looking at aligning to the requirements of the TCFD.

Improving energy efficiency of school buildings during winter season using passive design strategies

Passive building design can improve energy efficiency of buildings, while providing comfortable indoor environment for occupants with minimum mechanical energy use. The foundation of passive design depends on natural sources of energy, which uses building architecture and surrounding environment to minimise heating and cooling loads of buildings with minimum operating and maintenance costs. The correlation of local climate with shape and thermal performance of buildings is one of the main considerations of passive design approach to reduce energy use and increase thermal comfort of occupants. This paper focuses on a series of field studies and building simulation analysis to improve thermal performance of female secondary school buildings in the city of Tehran in Iran during winter season using passive design strategies. The field studies included measuring indoor air temperature, as well as a questionnaire-based survey in a cold winter season in a typical female secondary school building. The on-site monitoring assessed indoor air temperature of classrooms while the occupants completed questionnaires covering their thermal sensations and thermal preferences. Moreover, building thermal simulation analysis were carried out using DesignBuilder tool to evaluate and improve thermal performance of classrooms based on students' thermal requirements and passive design strategies. The simulation analysis started from the basic school building model, investigating various passive design strategies to predict the optimum design strategies for the case study. The simulation results determined how to provide classrooms that are more comfortable for students with minimum energy use. The results of the field studies indicated that indoor thermal environment were usually comfortable for female students based on 7-point ASHRAE scale. However, most of the occupants preferred their indoor thermal environment to be improved. Moreover, simulation results showed that building fabrics and thermal properties, as well as glazing and orientation had significant impacts on indoor air temperature and thermal comfort and using appropriate passive design strategies could improve energy efficiency of the building considerably. Therefore, in order to enhance indoor thermal environment and to increase learning performance of students, it is necessary to use appropriate low energy methods, which can reduce the needs for mechanical energy systems and hence save energy.

The pavilions of Expo 2015 in Milan, as a privileged observatory about the concept of sustainable construction in all languages of the world

The organization of Expo 2015 in the city of Milan has prompted massive organizational efforts to set up a new fair district in one of the largest Italian cities. The urban layout of the metropolitan city has been redesigned in order to accommodate all participating nations event. Expo 2015 established through guidelines the necessity to adopt sustainable solutions for the temporary buildings of the exhibition. The article aims to see how the concepts of sustainability and recyclability have been interpreted in the language of 40 designers from different countries. Through data provided by information papers of the exhibition, a valuation of materials used in buildings was made. This research led to an analysis of different building typology involved and the materials most used to reach the goals of guidelines drawn up by Expo 2015. The perception of an event characterized by green constructions was achieved, but not every construction was aimed to be a nearly zero emission building.

Adopting green building constructions in developing countries through capacity building strategy: survey of Enugu State, Nigeria

Green building (GB) constructions seeks to address housing demands of the growing populace with better qualities, energy efficiency, using recycled and recyclable materials, improve building lifespan and health of occupants. But GB adoption lags in developing countries. This study focused on driving the adoption of GB constructions in developing countries through capacity building strategy: survey of Enugu State, Nigeria. Structured questionnaire was used to collect data from 135 building workers in educational and industrial sectors across the registered construction companies and higher institutions in Enugu State. Mean and rank were used to answer the research questions, while t-test was used to test five null hypotheses at 0.05 level of significance. Results revealed that there is need for capacity building in: GB design, GB site, GB construction, GB operation and maintenance, and GB construction and demolition waste management. Cluster t-test analysis showed discrepancies in the agreement of educational and industrial sector workers on GB design and GB construction needs. The implications for not adopting GB are continual conventional constructions with maximal exploitations and resource depletion. Thus, there is a gap in knowledge where sustainable development advocates, government and pioneers of green construction practices could channel efforts toward assisting the developing countries.

Parametric multi-objective energy and cost analysis in the life cycle of nearly zero energy buildings − an exhaustive search approach

Possible cost saving potentials in planning and construction of high performing nearly zero energy buildings (nZEBs) with advanced energy standards are often not sufficiently assessed, as only a few, out of numerous possible variants of technology sets are considered in the traditional planning process. Often planning and analysis are not carried out in parallel, and the alternative technical options are discarded at an early stage. If, on the other hand, possible variants are realistically compared in the planning phase, a profound decision can be made. nZEB-design is also a multi-objective optimization problem where stakeholder interests' conflict with each other. This research addresses a methodological approach to better understand the effects that technical variables have on energy, environmental and economic performance over the whole life cycle of a multi-family residential building in Sweden. The research goal is to identify the most significant technical nZEB design variables organized into a consistent framework. In this paper, in a first step an exhaustive search method is assessed for a multi-family residential building in Sweden that systematically investigates all possible variant combinations. In a second step the derived results are applied to multiple objectives and optimisation goals for a multi-target decision-making framework so that different actors can decide between optimal solutions for different objectives. This approach seeks to explore a set of optimal solutions rather than to find a single optimal solution. On the one hand, a variety of technologies, such as insulation of the building envelope, ventilation or electricity and heat supply, and on the other hand a variation of the boundary conditions (such as observation period, user behaviour, energy price increases or CO2 costs) was investigated. The results were analysed energetically and economically over the life cycle of the building with the objectives of identifying coherences, deriving trends and optimizations over a time span of 40 years. The results show that the variance in the financing costs (20%) and the net present value (15%) is relatively low, whereas the primary energy demand (66%) and the CO2 (73%) emission vary in a broader range. The optimum cost curve in relation to CO2 emissions is very flat. Low emissions and energy requirements can, therefore, be achieved with different energy concepts as long as the envelope is very efficient. Due to the nature of an exhaustive search approach, it is also possible to find technical solution sets and design strategies with nearly equal financing cost and/or net present values, but with less primary energy consumption and/or CO2 emissions.

Hygrothermal behaviour of straw bale walls: experimental tests and numerical analyses

Straw is an organic material with hygroscopical properties. The high capacity it has of storing moisture from the surroundings can furthermore influence the performance and lead to the possible degradation of the material thereof. The aim of this study was to assess the conductance C-value of a complex material such as straw. A climatic chamber was used to study a sample, which reproduces a traditional plastered straw bale wall. Tests were conducted under different boundary conditions, setting constant values for temperatures and relative humidity. The revision of the assessment's results allowed the calculation of conductance and conductivity values under different conditions. A numerical model was then designed starting from the laboratory data, which was used to characterize material properties. The match between software simulations and laboratory analyses will be a starting point for further tests. Determining the straw conductance C-value is a difficult task to achieve, due to the complexity and the unique properties of the material. In spite of all this, laboratory tests have shown encouraging results, which reflect the great potential of straw as a building material.

Are we ready for circular economy? Towards zero waste in construction

Over the past decade, the concept of circular economy (CE) has emerged encouraging a rethinking of the way products are designed so that they can be “made to be made again”, turning the conveyor belt of consumerism into a circle (a closed-loop supply chain) and hence eliminate waste. The construction sector, especially, is known to be one of the main contributors of material waste-to-landfill. This paper investigates (i) the causes of construction waste and (ii) the readiness of the construction sector in Malaysia to embrace CE. Based on the relative importance index (RII), the five main causes of construction waste in Malaysia identified include frequent design changes (RII = 0.853) by owner or agent during construction followed by poor site management and supervision (RII = 0.835), changes in material specification and type (RII = 0.803), rework (RII = 0.719) and lack of coordination between parties (RII = 0.680). Survey findings also show that a majority (75%) of stakeholders within the Malaysian construction industry is unfamiliar with the concept of CE while 90% of the respondents claim that they are not ready to implement such practices within the next 5 years. It is anticipated that the findings from this paper will be of interest to construction practitioners.

Solar water heating systems for different buildings under a hot climate; parametric optimization and economic analysis

Building applied solar thermal systems are considered by different stakeholders an attractive alternative to traditional space and water heating systems. However, their performance depends largely on climatic conditions, water heating needs and operational parameters which, in turn, offer opportunities for performance optimization. The present research attempts to provide architects with a design decision tool that integrates solar thermal collectors efficiently to meet hot water demand for various building types inclusive of residential, commercial and industrial in a hot climate. The analysis is conducted numerically through a thermal model developed and executed in TRNSYS and validated experimentally. The parameters investigated include the collector tilt angle, azimuth angle and collector inlet fluid flow rate. Finally, the collector aperture area required per building foot print area is determined. The research revealed that for a 1000 m2 footprint building area of schools, offices, residential, factories and hospitals would require respectively 8 m2, 10 m2, 14 m2, 24 m2 and 38 m2 of the static collector installed at 24° tilt angle with optimal water flow rate. Additional operational aspects of collector tracking, and solar radiation concentration were investigated and further reduce the required collector area. A simple payback period analysis reveals a return on investment of 2 years applying subsidized tariff rates under the climatic conditions of, or similar to Dubai, in the United Arab Emirates.