Varias medidas se están llevando a cabo en Uruguay para reducir las emisiones de CO2 a la atmósfera, entre las que destaca la modificación de la matriz energética. En estos últimos años más del 90 % ...de la energía eléctrica que se produjo provino de fuentes renovables, tales como la eólica, la hidroenergía o la biomasa. A pesar de estos progresos, el sector de la edificación, la construcción y el transporte continúan siendo en gran parte responsables de los impactos ambientales que producen las actividades humanas en el país. Por otra parte, diversos estudios muestran el avance en el desarrollo de metodologías de cálculo y la definición de estrategias que permitan reducirlas. En ese sentido la metodología del Análisis del Ciclo de Vida (ACV) es considerada una de las más trasparentes y reconocidas por la comunidad científica internacional. Este estudio tiene por objetivo el desarrollo de una propuesta metodológica basada en el ACV, para calcular los impactos ambientales que producen los edificios residenciales en madera durante su ciclo de vida. La verificación experimental se desarrolla a través del caso de “La Casa Uruguaya”, una vivienda social unifamiliar construida en madera. La metodología propuesta permite, a partir de la fase avanzada del diseño de la vivienda, obtener resultados de los impactos ambientales que se producen durante su ciclo de vida completo. Los resultados demuestran la relevancia de las etapas de uso (uso de energía, mantenimiento, reparación, rehabilitación y sustitución) y de producto (extracción de materias primas, fabricación y transporte) sobre el resto de las fases del ciclo de vida consideradas.
The main objective of this article is to propose possible requirements for cost-optimal plus energy building in a cold, heating dominated climate. The open question is what is more cost-effective: ...reduction of energy demand or increase of production from renewable energy sources. The target of the research was to check which solution has the lowest investment and maintenance costs. The analysis was made for a single-family house located in central Poland, including three different energy standards: WT2021 with energy need for heating ≤100 kWh/(m² year), NF40 with energy need for heating ≤40 kWh/(m² year) and NF15 with energy need for heating ≤15 kWh/(m² year)). Air and ground source heat pumps were used as a heat source and a photovoltaic system for the production of the electrical energy. For each case the investment and running costs were calculated very precisely, taking into account heating, ventilation, domestic hot water and auxiliary systems. Global cost for a 30-year period showed that house variants with air source heat pumps are more cost effective. The investment, replacement and maintenance cost related with energy systems have the biggest share in the global cost. Reaching the plus energy standard was possible only in the case of low-energy standard NF40 and NF15. Based on this research the proposed requirements for plus energy single-family residential buildings in central Poland are the following: the final (delivered) electrical energy demand (including heating, ventilation, domestic hot water and auxiliary systems) <45 kWh/(m² year) and the on-site electrical energy production >45 kWh/(m² year).
In buildings with good-quality thermal insulation of external partitions, the main component of the building’s heat balance is the heat demand for ventilation. The reduction of this energy demand ...cannot be achieved at the expense of thermal comfort of the occupants and indoor air quality. The aim of this article is to analyze the impact of various ventilation strategy (natural and mechanical) on heating demand, thermal comfort, and CO2 concentration in a single-family house located in Poland. The benefits of using fans integrated with the earth tube were tested. The study was based on the numerical energy simulation of a multi-zone building model for the entire calendar year. Contam, EnergyPlus, and Python programs were used to perform calculations. The thermal model was validated on the results of temperature measurements in the building. To obtain the best solutions, the parameters of the systems considered have been optimized with the use of genetic algorithms. Various optimal parameters of the earth tube (diameter, length, and foundation depth) were obtained during this research. The highest number of thermal discomfort hours was obtained in the naturally ventilated building with automatic window opening. This system supplied to the rooms a large amount of cool outdoor air in winter and warm air in summer, causing instantaneous rapid fluctuations in indoor temperature. Supplementing the mechanical ventilation control system with CO2 concentration sensors resulted in a much higher amount of ventilation air supplied to the rooms compared to systems controlled only by temperature sensors, resulting in an increase in heat demand.
The building and construction sector is vital in Jordan. Over the past decade it witnessed rapid growth. Single-family housing is a popular option in Jordan. The construction sector consumes large ...amounts of energy and resources. Green and energy efficient buildings are growing in popularity and there are policies adopted to encourage energy efficient buildings. These buildings are often justified based on energy saving during the operation phase. Nevertheless, up to date, there is no study that analyses the efficiency of these buildings in Jordan from a life cycle perspective. In this study, the six most popular construction configurations for a single family house in Jordan are assessed using “cradle to grave” life cycle methodology. The alternatives included: single hollow concrete block (Economic), double layer hollow concrete blocks (improved economic), double layer hollow concrete blocks with insulation layer (insulated economic), typical limestone cladding, insulated limestone wall and multi-layer with limestone cladding and insulation (luxury). The results show that using the typical Jordanian family thermal comfort level and heating and cooling patterns, the economic house is the option that performs best in terms of energy resources (5050 UBP), climate change (727.85 Mg CO2 eq), acidification (2.91 Mg SO2 eq) and particulate matter formation (1.14 Mg PM10 eq). Limestone cladded houses show better results in terms of human toxicity and water depletion impact. The results further suggest that energy resource and water depletion impacts may be used as proxy indicators for the overall performance of the building.
•The 6 most common single-family house construction were evaluated using LCA.•Low energy demand due climate and Jordanian family HVAC use patterns.•Energy savings during the operation phase do not make up for LCA impacts.•Single layer hollow concrete block wall has the lowest environmental impacts.•Energy resource impact and water depletion impacts are good proxy indicators.
Representing 30% of the energy consumption in Sweden, the built environment is a clear contender for climate mitigation initiatives. The substantial stock of single-family houses presents ample ...opportunities to engage in energy-saving refurbishments. However, despite political pressure, only a minority of these refurbishments includes low-energy retrofit. To explain this slow take-off, studies have mostly focused on the necessity to better link new technical solutions with user needs and behaviours. We propose to extend this analysis to a broader set of actors including the craftsmen contracted to carry out the refurbishments and the houses themselves with their specific features and characteristics. To do so, we build our contribution on the concept of sociomateriality. This perspective argues that technological artefacts are socially constructed, but recognizes that materiality also has a role to play. Drawing on the experiences of 24 small craftsman firms, 8 houses as well as their owners, our method comprises interviews, workshops and participant observation complemented by an in-depth case study. The results show many differentiated representations of the renovation process under scrutiny. All these representations need to be understood and to a certain degree aligned in order to achieve successful retrofits.
•Green roof technology is examined for two different typical residential buildings.•Great energy and environmental benefits are achieved against conventional constructions.•Sensitivity analysis shows ...that green roofs become financially favorable with modest reduction in current installation cost.•At the neighborhood scale the calculated decrement in air temperature at the pedestrian level is noticeable.
Green roofs are considered as an appropriate nature-based measure to increase the environmental resilience of cities. This paper examines this technological solution applied to typical urban residential buildings in the Mediterranean island of Cyprus, with respect to energy, environmental, and economic aspects. The analysis shows a clearly positive energy and environmental contribution of green roofs. Although such an investment does not seem to be cost-effective in residential buildings, sensitivity analysis demonstrates that green roofs become financially favorable compared to flat roof constructions with only modest reductions in their current installation cost. Moreover, green roofs offer environmental benefits that are currently difficult to monetize, which can clearly improve urban resilience to climate change. In order to quantify the impact of green roof installations on the surrounding environment, the analysis was expanded from the individual building perspective to neighborhood scale implementation, using appropriate simulation software to evaluate the contribution of green roofs to urban heat island mitigation. Focusing on the ambient air temperature at the pedestrian level, a noticeable decrease was estimated.
•Comparison of thermal and electrical storage in reducing mismatch.•Comparison of solar tracking strategy and fixed tilt angle in reducing mismatch.•Influence of micro-wind turbine numbers and hub ...heights in reducing mismatch.•Simple payback time of micro-wind turbine and PV for single-family house.•Simple payback time when grid feed-in option is available.
This paper conducts analyses and proposes solutions for reducing mismatch between renewable energy (RE) production and electrical demand from a 150m2 single-family house. The RE options are photovoltaic (PV) and micro-wind turbine. This paper mainly focuses on the situation when grid feed-in is not available, but a brief economic analysis with grid feed-in is also conducted at the end of the paper. This paper specially investigates the influence of electrical storage in batteries and thermal storage in a domestic hot water (DHW) tank with suitable RE-DHW recharging strategies. The simulation results show that the recharging strategy of excess renewable electricity to a DHW storage tank with one day's DHW volume is more technically and economically effective than using electrical battery in reducing annual mismatch. Even without battery, the improvement in reducing mismatch can be 12.7–23.3% simply by using the RE-DHW recharging strategy. Furthermore, PV with 2-axis solar tracking strategy is not economically feasible in the Nordic climate, whereas south-facing PV with a 45° fixed tilt angle is recommended. Moreover, from both the energy and economic points of view, the increased hub height with multiple turbines is preferable for the application with a 6.64–16.2% improvement in reducing mismatch.
PDF
