Search

Building load forecasting is critical for energy saving and carbon emission reduction, as building loads account for a rising percentage of energy consumption. Existing load forecasting methods only target a single building and do not consider the spatial characteristics of different building loads in an architectural complex, making it impossible to effectively forecast loads for all buildings in an architectural complex simultaneously. In this paper, considering the spatial correlation among building loads in an architectural complex, a novel short-term load forecasting method is proposed to improve the load forecasting accuracy for the architectural complex. First, Pearson correlation analysis is carried out to determine the key influencing factors of load, which are treated as multi-information. Then, to realize the load forecasting of all buildings in an architectural complex at the same time, a multi-information fusion model combined with a graph convolutional network and a long-short term memory network is proposed, and spatio-temporal attention modules are included to extract the dynamic spatio-temporal correlations of load. The performance of the proposed model is evaluated using actual load data from a public university in Beijing. When compared to other current methods, the experimental results show that the proposed model not only achieves the best results for architectural complex load forecasting (the largest MAPE is only 6.86%, the smallest R2 and Accuracy reach 0.87 and 0.85, respectively), but also maintains forecasting stability to some extent over a longer forecast period. The proposed method is a meaningful step towards achieving fast and accurate architectural complex load forecasting. [ABSTRACT FROM AUTHOR]

• A heat pump simultaneously driven by a gas engine and an electrical motor proposed. • A prototype was developed and tested to approve the feasibility. • Compressor rotation speed and engine power ratio can both change the heating capacity. • Engine power ratio can be adjusted for better efficiency and economic performance. • The heat pump has higher efficiency and less operating costs than traditional systems. The gas engine-driven heat pump (GEHP) has a higher primary energy ratio (PER) than the electric heat pump (EHP) for heating, but has a lower PER than the EHP for cooling. To exploit the advantages of GEHP and EHP, a heat pump system where the compressor could be driven simultaneously by a gas engine and motor was proposed in the paper. An experimental platform was established to investigate the feasibility and performance of the HPHP system. In addition, numerical models were built for further performance analyses. The results indicate that: (1) Increases in the rotation speed of the compressor and engine power ratio lead to an increase in the total heating capacity. The rotation speed should be adjusted first to meet the required heating load, and then the engine power ratio can be adjusted to achieve better performance; (2) Engine power ratio changes the loads of the engine and motor, thus their efficiencies change, leading to different PERs of the HPHP system. Under different local gas and electricity prices, the engine power ratio can also be adjusted to reach a minimum operating cost; (3) For the case-studied commercial building in Beijing, the annual primary energy consumptions for HPHP, GEHP, and EHP are 94.2, 95.7, and 100.0 kWh/m2, respectively. In addition, HPHP saves operating costs by 17.5 % and 35.1 % compared to GEHP and EHP, respectively, with static payback periods of 2.45 and 1.47 years, even if it is only used for heating in winter. [ABSTRACT FROM AUTHOR]

Lighting is necessary for all kinds of buildings and consumes a large amount of electricity. Tubular daylighting devices (TDDs) can serve as an alternative, but they may also have thermal effects on the indoor environment, which has not been studied yet. In this paper, a lighting-heating coupled TDDs system was designed and built, to improve the use of TDDs for building energy savings and sustainability, where antimony tin oxide (ATO) nanofluids were introduced to absorb extra unexpected heat and then supply domestic hot water. Meanwhile, a new method was developed to calculate the annual amount of energy output of TDDs under different mass concentrations of ATO nanofluids. Results showed that the ATO nanofluids of 100 ppm can absorb ∼ 50% solar radiation coming along with more efficient visible lighting. Furthermore, in the case study in Beijing, TDDs with 100 ppm ATO nanofluids could generate over 10 tons of domestic hot water while saving 30.9 kWh of electricity for refrigeration, resulting in a ∼ 10% improvement on total energy-saving performance. This research work demonstrates the high potential of using the designed lighting-heating coupled TDDs system in buildings for both energy savings and daylighting benefits. [ABSTRACT FROM AUTHOR]

• Household energy transition does not necessarily improve subjective welfare. • Thermal insulation of homes could improve subjective evaluation. • Advanced technology and lower cost of heating lead to higher satisfaction. • Enforcing energy transition as a mandate reduces households' satisfaction. • Higher-income households are more satisfied with household energy transition. Household energy transition is beneficial to the environment and public health. However, the subjective welfare of the participants is not guaranteed to be improved. This paper takes China's clean heating program as an example of household energy transition and investigates the factors that affect participants' satisfaction with the program. Based on a large-scale household survey in Beijing, we find that the households' evaluation of indoor temperature, air quality, cleanliness, heating convenience, and safety is positive overall, but there is substantial heterogeneity in opinions, program implementation, and household characteristics. Utilizing econometric models, we further find that (1) thermal insulation of the home can improve subjective evaluation of warmth; (2) more advanced heating technology and lower cost of equipment acquisition are associated with higher satisfaction; (3) providing information to households results in more positive evaluation of the program, while enforcing the program as a mandate reduces households' satisfaction; and (4) higher-income households are more likely to give the program a higher evaluation. Based on these findings, follow-up policies could promote thermal insulation, increase equipment subsidies for low-income groups, and relax strict mandates. [ABSTRACT FROM AUTHOR]

• A framework for retrofitting existing houses to NZEBs is proposed. • The framework includes renewable system design, building envelope improvement and energy system retrofit. • The framework practicability and reliability were demonstrated in a real building retrofit. • Energy consumptions before and after retrofit were presented and compared. Nearly zero energy building is a promising solution for tackling the conflict between the reducing fossil fuel reserves and the ever-increasing energy demand. Initiatives and goals for nearly zero energy buildings have been announced in different countries, as well as a series of strategies and incentives for advocating renewable energy applications. Within this context, homeowners' energy awareness has been strengthened and more and more of them are willing to invest on energy efficiency improvement and renewable energy application. However, there is no clear method or procedure for common practitioners to follow in the practice of energy retrofit of existing buildings, more specifically existing houses. This paper fills this pressing research gap by developing a framework for retrofitting existing houses to nearly zero energy buildings. The developed framework is then implemented on a real house in Beijing to demonstrate its reliability and practicability. The innovations of this study lie in the full consideration of the actual conditions of existing houses as well as the practicability of the framework, and for the first time, the detailed energy performance measurements of a real-life house from its original inefficient condition to after being retrofitted to a nearly zero energy building are presented. The framework can be easily extended to applications of other renewables and serve as a guideline for the wide common practitioners in their real building renovation practices. [ABSTRACT FROM AUTHOR]