Numerical investigation of the energy saving potential of a semi-transparent photovoltaic double-skin facade in a cool-summer Mediterranean climate

Air-conditioning systems contribute the most to energy consumption among building equipment. Hence, energy saving for air-conditioning systems would be the essence of reducing building energy consumption. The conventional energy-saving diagnosis method through observation, test, and identification (OTI) has several drawbacks such as time consumption and narrow focus. To overcome these problems, this study proposed a systematic method for energy-saving diagnosis in air-conditioning systems based on data mining. The method mainly includes seven steps: (1) data collection, (2) data preprocessing, (3) recognition of variable-speed equipment, (4) recognition of system operation mode, (5) regression analysis of energy consumption data, (6) constraints analysis of system running, and (7) energy-saving potential analysis. A case study with a complicated air-conditioning system coupled with an ice storage system demonstrated the effectiveness of the proposed method. Compared with the traditional OTI method, the data-mining-based method can provide a more comprehensive analysis of energy-saving potential with less time cost, although it strongly relies on data quality in all steps and lacks flexibility for diagnosing specific equipment for energy-saving potential analysis. The results can deepen the understanding of the operating data characteristics of air-conditioning systems.

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Influence of sizing strategy and control rules on the energy saving potential of heat pump hybrid systems in a residential building

Energy Conversion and Management ◽

10.1016/j.enconman.2021.114022 ◽

2021 ◽

Vol 235 ◽

pp. 114022

Author(s):

Matteo Dongellini ◽

Claudia Naldi ◽

Gian Luca Morini

Keyword(s):

Energy Saving ◽

Hybrid Systems ◽

Heat Pump ◽

Residential Building ◽

Energy Saving Potential ◽

Control Rules ◽

And Control

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Energy-saving potential evaluation for primary schools with occupant-centric controls

Applied Energy ◽

10.1016/j.apenergy.2021.116854 ◽

2021 ◽

Vol 293 ◽

pp. 116854

Author(s):

Yunyang Ye ◽

Yan Chen ◽

Jian Zhang ◽

Zhihong Pang ◽

Zheng O’Neill ◽

...

Keyword(s):

Energy Saving ◽

Primary Schools ◽

Energy Saving Potential ◽

Potential Evaluation

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Thermal comfort in winter incorporating solar radiation effects at high altitudes and performance of improved passive solar design—Case of Lhasa

Building Simulation ◽

10.1007/s12273-020-0743-x ◽

2020 ◽

Author(s):

Lingjiang Huang ◽

Jian Kang

Keyword(s):

Solar Radiation ◽

Thermal Comfort ◽

Energy Saving ◽

Solar Irradiance ◽

Indoor Environment ◽

Thermal Mass ◽

High Altitudes ◽

Energy Saving Potential ◽

Environment Control ◽

Passive Solar

AbstractThe solar incidence on an indoor environment and its occupants has significant impacts on indoor thermal comfort. It can bring favorable passive solar heating and can result in undesired overheating (even in winter). This problem becomes more critical for high altitudes with high intensity of solar irradiance, while received limited attention. In this study, we explored the specific overheating and rising thermal discomfort in winter in Lhasa as a typical location of a cold climate at high altitudes. First, we evaluated the thermal comfort incorporating solar radiation effect in winter by field measurements. Subsequently, we investigated local occupant adaptive responses (considering the impact of direct solar irradiance). This was followed by a simulation study of assessment of annual based thermal comfort and the effect on energy-saving potential by current solar adjustment. Finally, we discussed winter shading design for high altitudes for both solar shading and passive solar use at high altitudes, and evaluated thermal mass shading with solar louvers in terms of indoor environment control. The results reveal that considerable indoor overheating occurs during the whole winter season instead of summer in Lhasa, with over two-thirds of daytime beyond the comfort range. Further, various adaptive behaviors are adopted by occupants in response to overheating due to the solar radiation. Moreover, it is found that the energy-saving potential might be overestimated by 1.9 times with current window to wall ratio requirements in local design standards and building codes due to the thermal adaption by drawing curtains. The developed thermal mass shading is efficient in achieving an improved indoor thermal environment by reducing overheating time to an average of 62.2% during the winter and a corresponding increase of comfort time.

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