Tailored domestic retrofit decision making towards integrated performance targets in Tianjin, China

Due to global warming and energy exhaustion, building retrofitting has attracted increasing attention worldwide. With 67.1 billion square meters of existing building area, China normally targets separate defect remedies to improve building energy efficiency in conventional renovation practices rather than taking a holistic approach to optimize whole building performance. This article presents a working procedure that is employed in the decision-making process of domestic retrofits in China from an architect’s perspective, combining building-sculpt redesign with the overall performance targets. This study examines three representative residences of different ages and dimensions as case studies to demonstrate a simulation-based holistic approach of integrating form, fabric and system strategies to improve environmental performance and reduce house-hold energy consumption without compromising building aesthetics in retrofit design. Different retrofit routes and corresponding priorities should be applied towards different conditions for different purposes. The simulation results indicate that within the service life, the older the residence, the greater the retrofit potential. For the 1981 residence, a holistic approach could achieve an energy savings of 78.1% and a CO2 savings of 92.6%. For the 1995 case, the holistic approach could reduce energy consumption by 66.6% and CO2 emissions by 76.6%. When designed properly, a 36.9% reduction in energy consumption and a 44.6% reduction in CO2 emissions could be achieved for the 2002 residence

Sustainable university library design: a case study of the library design in Weifang Science and Technology College

Through analyzing the projects of eco-libraries in China and abroad, this paper explores ecological strategies for university library design by taking the library design of Weifang Science and Technology College as an example. The strategies include building layout, modular interior design, double-roof, atrium air flow, overhead space of ground floor design, etc. What’s important is that the study uses some software to test the energy efficiency of the double-roof, and to simulate the operations of passive shading and ventilation to choose the most effective shading and ventilation installations. This paper also does some research on place construction and community creation. It’s hoped that these results and design approach will provide examples for the university library design in China

Sustainable university library design: a case study of the library design in Weifang Science and Technology College

Through analyzing the projects of eco-libraries in China and abroad, this paper explores ecological strategies for university library design by taking the library design of Weifang Science and Technology College as an example. The strategies include building layout, modular interior design, double-roof, atrium air flow, overhead space of ground floor design, etc. What’s important is that the study uses some software to test the energy efficiency of the double-roof, and to simulate the operations of passive shading and ventilation to choose the most effective shading and ventilation installations. This paper also does some research on place construction and community creation. It’s hoped that these results and design approach will provide examples for the university library design in China

Effect of geometric factors on the energy performance of high-rise office towers in Tianjin, China

To improve energy efficiency of office buildings in Tianjin, we select a prototypical high-rise office tower as an example and focus on the effect of geometric factors on building energy performance. These factors include the orientation, plane shape, floor area, plane shape factor (the ratio of the plane length to the plane width, only as regards to a rectangle-shaped plane), floor height, floor number and window-to-wall ratio. The simulation is performed in DesignBuilder, which integrates artificial lighting with instantaneous daylight during the energy simulation process. The geometric factors of the defined prototype are examined in both single-parameter and multi-parameter evaluations. As to the multi-parameter results, the energy saving rate can vary by up to 18.9%, and reducing the floor height is observed to be the most effective means of reducing annual total end-use energy consumption, followed by increasing the plane shape factor and reducing the floor area. The results can serve as a reference for passive design strategies related to geometric factors in the early design stage

Peatland Heterogeneity Impacts on Regional Carbon Flux and Its Radiative Effect Within a Boreal Landscape

Peatlands, with high spatial variability in ecotypes and microforms, constitute a significant part of the boreal landscape and play an important role in the global carbon (C) cycle. However, the effects of this peatland heterogeneity within the boreal landscape are rarely quantified. Here, we use field-based measurements, high-resolution land cover classification, and biogeochemical and atmospheric models to estimate the atmosphere-ecosystem C fluxes and the corresponding radiative effect (RE) for a boreal landscape (Kaamanen) in northern Finland. Our result shows that the Kaamanen catchment currently functioned as a sink of carbon dioxide (CO2) and a source of methane (CH4). Peatlands (26% of the area) contributed 22% of the total CO2 uptake and 89% of CH4 emissions; forests (61%) accounted for 78% of CO2 uptake and offset 6% of CH4 emissions; water bodies (13%) offset 7% of CO2 uptake and contributed 11% of CH4 emissions. The heterogeneity of peatlands accounted for 11%, 88%, and 75% of the area-weighted variability (deviation from the area-weighted mean among different land cover types (LCTs) within the catchment) in CO2 flux, CH4 flux, and the combined RE of CO2 and CH4 exchanges over the 25-year time horizon, respectively. Aggregating peatland LCTs or misclassifying them as nonpeatland LCTs can significantly (p < 0.05) bias the regional CH4 exchange and RE estimates, while differentiating between drier noninundated and wetter inundated peatlands can effectively reduce the bias. Current land cover products lack such details in peatland heterogeneity, which would be needed to better constrain boreal C budgets and global C-climate feedbacks. Plain Language Summary Peatlands form part of the boreal landscapes exhibiting diverse types and microforms that have different characteristics of topography, hydrology, vegetation, and soil. Our understanding is still limited concerning how boreal peatlands, especially their inherent heterogeneities, affect the regional biosphere-atmosphere exchange of carbon and related climate effects, and what level of detail is needed to characterize them in land cover maps. By combining remote sensing information, field measurements, and biogeochemical modeling, we showed that, among different land cover types, peatlands played a dominant role in the variability of methane (CH4) flux (88%) and the combined radiative climate effect due to carbon dioxide and CH4 exchanges (75% over the 25-year time horizon). Possible aggregation and misclassification of peatland types could induce significant biases in the regional CH4 balances and radiative effect estimates, but the distinction of noninundated drier and inundated wetter peatland types could reduce these biases effectively.Peer reviewe

Research on passive low energy buildings technologies based on multi-objective optimization method——taking cold zone residential buildings for example

To improve the summer time overheating and high incremental cost problems of passive low energy buildings and further promote the development of passive low energy buildings in China, we establish a set of multi-objective optimisation method for passive low energy buildings in China. A high-rise residential building in Tianjin is selected as a case study to apply this method. According to the results, the integrated optimal solutions can save 25%~35% energy compared to the reference model. And three different target-oriented technology templates are concluded according to the primary energy consumption. They are energy efficiency optimal template, cost optimal template and trade-off template

Reduction Strategies for Greenhouse Gas Emissions from High-Speed Railway Station Buildings in a Cold Climate Zone of China

Implementing China’s emission reduction regulations requires a design approach that integrates specific architectural and functional properties of railway stations with low greenhouse gas (GHG) emission. This article analyzes life cycle GHG emissions related to materials production, replacement and operational energy use to identify design drivers and reduction strategies implemented in high-speed railway station (HSRS) buildings. A typical middle-sized HSRS building in a cold climate zone in China is studied. A detailed methodology was proposed for the development and assessment of emission reduction strategies through life cycle assessment (LCA), combined with a building information model (BIM). The results reveal that operational emissions contribute the most to total GHG emissions, constituting approximately 81% while embodied material emissions constitute 19%, with 94 kgCO2eq/m2·a and 22 kgCO2eq/m2·a respectively. Optimizing space can reduce operational GHG emissions and service life extension of insulation materials contributes to a 15% reduction in embodied GHG emissions. In all three scenarios, the reduction potentials of space, envelope, and material type optimization were 28.2%, 13.1%, and 3.5% and that measures for reduced life cycle emissions should focus on space in the early stage of building design. This study addresses the research gap by investigating the life cycle GHG emissions from HSRS buildings and reduction strategies to help influence the design decisions of similar projects and large space public buildings which are critical for emission reduction on a larger scale

Assessing Long-Term Thermal Environment Change with Landsat Time-Series Data in a Rapidly Urbanizing City in China

The studies of urban heat islands or urban thermal environments have attracted extensive attention, although there is still a lack of research focused on the analysis of long-term urban thermal environment change with fine spatial resolution and actual exposure of urban residents. Taking the rapidly urbanizing city of Nanjing, China as an example, this study utilizes the Landsat-derived daytime time-series land surface temperature data to comprehensively assess the city’s long-term (30-year) urban thermal environment change. The results showed that: (1) The overall surface urban heat island intensity showed a noticeable trend of first increasing and then decreasing from 1990 to 2020. (2) It exhibited the detailed spatial distribution of urban heat/cold islands within the urban center boundary. The percentage of surface urban heat islands was 77.01% in 1990, and it increased to 85.79% in 2010 and then decreased to 80.53% in 2020. (3) More than 65% of the urban residents have lived in areas with a surface urban heat island intensity greater than 3.0 °C, which also showed a trend of first increasing and then decreasing from 1990 to 2020. The methods and findings of this study can provide a reference for other studies on urban thermal environment changes and urban sustainable development