Making the ‘rebound effect’ more useful for performance evaluation of thermal retrofits of existing homes: Defining the ‘energy savings deficit’ and the ‘energy performance gap’

2014 ◽  
Vol 69 ◽  
pp. 515-524 ◽  
Author(s):  
Ray Galvin
Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1480 ◽  
Author(s):  
Qadeer Ali ◽  
Muhammad Jamaluddin Thaheem ◽  
Fahim Ullah ◽  
Samad M. E. Sepasgozar

Rising demand and limited production of electricity are instrumental in spreading the awareness of cautious energy use, leading to the global demand for energy-efficient buildings. This compels the construction industry to smartly design and effectively construct these buildings to ensure energy performance as per design expectations. However, the research tells a different tale: energy-efficient buildings have performance issues. Among several reasons behind the energy performance gap, occupant behavior is critical. The occupant behavior is dynamic and changes over time under formal and informal influences, but the traditional energy simulation programs assume it as static throughout the occupancy. Effective behavioral interventions can lead to optimized energy use. To find out the energy-saving potential based on simulated modified behavior, this study gathers primary building and occupant data from three energy-efficient office buildings in major cities of Pakistan and categorizes the occupants into high, medium, and low energy consumers. Additionally, agent-based modeling simulates the change in occupant behavior under the direct and indirect interventions over a three-year period. Finally, energy savings are quantified to highlight a 25.4% potential over the simulation period. This is a unique attempt at quantifying the potential impact on energy usage due to behavior modification which will help facility managers to plan and execute necessary interventions and software experts to develop effective tools to model the dynamic usage behavior. This will also help policymakers in devising subtle but effective behavior training strategies to reduce energy usage. Such behavioral retrofitting comes at a much lower cost than the physical or technological retrofit options to achieve the same purpose and this study establishes the foundation for it.


Proceedings ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 18
Author(s):  
Alessandro Piccinini ◽  
Luis M. Blanes ◽  
Federico Seri ◽  
Letizia D’Angelo ◽  
Marcus M. Keane

This communication presents ModSCO, a web application that supports systematic energy performance evaluation using Reduced Order Models (ROM). These models are particularly useful in scenario with missing, incomplete or uncertain building information. The paper describes the theory behind ROM grey-box modelling and presents case studies that support the smart operation of energy systems by generating Energy Conservation Opportunities (ESCOs) for instance, to help ISO 50001 implementation. The ROM demonstrated to provide accurate results with a reduced effort. The acceptable calibration tolerance provided by the ASHRAE Guideline 14 is been used to demonstrate the ROM’s accuracy. Additionally, the ModSCO architecture and user interface is also described.


2020 ◽  
Vol 12 (14) ◽  
pp. 5820 ◽  
Author(s):  
Giuseppe Salvia ◽  
Eugenio Morello ◽  
Federica Rotondo ◽  
Andrea Sangalli ◽  
Francesco Causone ◽  
...  

Building retrofit is often reported to fail in achieving predicted energy savings; this mismatch in post-retrofit conditions is labeled the ‘energy performance gap’ and may be due to both occupant behavior and technical issues. In this study, the occupant is investigated through a case study of a recently retrofitted public housing in Milan inhabited by 500+ tenants. Informed by social practice theory and interviews to households, concurrent and interdependent elements in heating space are identified—including factors of comfort, competences involved and other interconnected practices. Patterns of continuity and change in setting thermal conditions in this retrofitted building emerge. In this respect, key dynamics of the occupants are related to rooted habits in managing heating, social norms of thermal comfort, mastered skills in dealing with technical devices and infrastructure and ways of organizing other routines such as laundry and forms of entertainment when services are limitedly accessible. The results inform plans for energy efficiency through building retrofit in which the integration of the social dimension and practices may contribute to maximizing the impact of the intervention and to limiting energy performance gap.


2016 ◽  
Vol 8 (4-3) ◽  
Author(s):  
Siva Jaganathan ◽  
Abdul Hakim Mohammed ◽  
Mohd Shahril Abdul Rahman

This study address energy performance evaluation uncertainities in design. To achieve energy efficiency in building, designer should incorporate energy performance evaluation approach to foresight energy performance failure during design. The research has  evaluated and compares the capabilities of energy performances evaluation approaches namely computational fluid dynamic approach, optimization algorithm, and coupled approach. Furthermore, descriptive review unveils the practical obstacles and challenges designers encounter during design life cycle and proposes future direction to mitigate inundated energy performance gap.


2021 ◽  
Author(s):  
M. Rajithan ◽  
◽  
D. Soorige ◽  
S.D.I.A. Amarasinghe ◽  
◽  
...  

Operational energy consumption in buildings has a crucial impact on global energy consumption. Nevertheless, significant energy savings can be achieved in buildings if properly designed, constructed, and operated. Building Energy Simulation (BES) plays a vital role in the design and optimisation of buildings. BES is used to compare the cost-effectiveness of energy-conservation measures in the design stage and assess various performance optimisation measures during the operational phase. However, there is a significant ‘performance gap’ between the predicted and the actual energy performance of buildings. This gap has reduced the trust and application of the BES. This article focused on investigating BES, reasons that lead to a performance gap between predicted and actual operational energy consumption of buildings, and the ways of minimising the gap. The article employed a comprehensive literature review as the research methodology. Findings revealed that reasons such as limited understanding of the building design, the complexity of the building design, poor commissioning, occupants’ behaviour, etc., influence the energy performance gap. After that, the strategies have been identified to minimise the energy performance gap such as proper commissioning, creating general models to observe occupants’ behaviour in buildings, and using the general models for energy simulation, ensuring better construction and quality through training and education, etc. Further, the findings of this study could be implemented by practitioners in the construction industry to effectively use energy simulation applications in designing energy-efficient and sustainable buildings.


2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Bryan Coyne ◽  
Eleanor Denny

AbstractIreland’s Climate Action Plan aims upgrade 500,000 homes to B2 Energy Performance Certificate (EPC) standard by 2030. Evidence of an Energy Performance Gap, where actual energy use differs from the EPC, could undermine progress towards such targets. This paper studies the energy performance gap for a general housing sample (n = 9923) over multiple years. It provides a novel comparison between whole-home energy use (electricity and gas) that accounts for fuel switching and removes potential rebound effects by excluding households that may have changed their behaviour following a retrofit. Results suggest that actual energy use is unresponsive to the EPC, with a range of 457 kWh/year observed across EPC-level averages for the entire sample. This difference equated to less than 5% of the sample average annual energy use observed. The Energy Performance Gap range features an average deficit of 17% below theoretical energy use. The least energy efficient dwellings feature an average difference ranging from − 15 to − 56% of the relevant EPC. Conversely, energy efficient houses display higher-than-theoretical energy use, with average surpluses ranging from 39 to 54% of the relevant EPC. Results sound a note of caution for policymakers that rely on a theoretical EPC to deliver real energy savings. Future EPCs could be improved by incorporating historical household energy usage to help improve models.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 749
Author(s):  
John H. Scofield ◽  
Susannah Brodnitz ◽  
Jakob Cornell ◽  
Tian Liang ◽  
Thomas Scofield

In this work, we present results from the largest study of measured, whole-building energy performance for commercial LEED-certified buildings, using 2016 energy use data that were obtained for 4417 commercial office buildings (114 million m2) from municipal energy benchmarking disclosures for 10 major U.S. cities. The properties included 551 buildings (31 million m2) that we identified as LEED-certified. Annual energy use and greenhouse gas (GHG) emission were compared between LEED and non-LEED offices on a city-by-city basis and in aggregate. In aggregate, LEED offices demonstrated 11% site energy savings but only 7% savings in source energy and GHG emission. LEED offices saved 26% in non-electric energy but demonstrated no significant savings in electric energy. LEED savings in GHG and source energy increased to 10% when compared with newer, non-LEED offices. We also compared the measured energy savings for individual buildings with their projected savings, as determined by LEED points awarded for energy optimization. This analysis uncovered minimal correlation, i.e., an R2 < 1% for New Construction (NC) and Core and Shell (CS), and 8% for Existing Euildings (EB). The total measured site energy savings for LEED-NC and LEED-CS was 11% lower than projected while the total measured source energy savings for LEED-EB was 81% lower than projected. Only LEED offices certified at the gold level demonstrated statistically significant savings in source energy and greenhouse gas emissions as compared with non-LEED offices.


2020 ◽  
Vol 13 (1) ◽  
pp. 235
Author(s):  
Fernando Martín-Consuegra ◽  
Fernando de Frutos ◽  
Ignacio Oteiza ◽  
Carmen Alonso ◽  
Borja Frutos

This study quantified the improvement in energy efficiency following passive renovation of the thermal envelope in highly inefficient residential complexes on the outskirts of the city of Madrid. A case study was conducted of a single-family terrace housing, representative of the smallest size subsidized dwellings built in Spain for workers in the nineteen fifties and sixties. Two units of similar characteristics, one in its original state and the other renovated, were analyzed in detail against their urban setting with an experimental method proposed hereunder for simplified, minimal monitoring. The dwellings were compared on the grounds of indoor environment quality parameters recorded over a period covering both winter and summer months. That information was supplemented with an analysis of the energy consumption metered. The result was a low-cost, reasonably accurate measure of the improvements gained in the renovated unit. The monitoring output data were entered in a theoretical energy efficiency model for the entire neighborhood to obtain an estimate of the potential for energy savings if the entire urban complex were renovated.


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