Evaluation of Cooling, Heating, and Power (CHP) Systems Based on Building Energy-Rating

Author(s):  
N. Fumo ◽  
P. J. Mago ◽  
L. M. Chamra

Cooling, Heating and Power (CHP) systems are a form of distributed generation that uses internal combustion prime-power engines to generate electricity while recovering heat for other uses. CHP is a promising technology for increasing energy efficiency through the use of distributed electric and thermal energy recovery-delivery systems at or near end-user sites. Although this technology seems to be economically feasible, the evaluation and comparison of CHP systems cannot be restricted to economical considerations only. Standard economic analysis, such as life cycle economic analysis, does not take in consideration all the benefits that can be obtained from this technology. For this reason, several aspects to perform a non-conventional evaluation of CHP systems have to be considered. Among the aspects to be included in a non-conventional evaluation are: power reliability, power quality, environmental quality, energy-efficient buildings, fuel source flexibility, brand and marketing benefits, protection from electric rate hikes, and benefits from promoting energy management practices. Some benefits of these non-economical evaluations can be transferred into an economic evaluation but others give intangible potential to the technology. This paper focus on a non-conventional evaluation based on energy-efficient buildings, which is associated to energy conservation and improvement of the building energy performance rating for government energy programs like Energy Star and Leadership in Energy and Environmental Design (LEED). Results show that the use of CHP systems could improve the Energy Star Rating in more than 50 points. The Energy Star Rating is significant on the LEED Rating as a building can score up to 10 points of the 23 available in the Energy & Atmosphere category on energy efficiency alone. As much as 8 points can be obtained in this category due to the Energy Star rating increment from the use of CHP systems. Clearly the use of CHP systems will help building owners to reach the benefits from these energy programs while improving the overall energy use and energy cost.

2021 ◽  
pp. 1420326X2110501
Author(s):  
Shambalid Ahady ◽  
Nirendra Dev ◽  
Anubha Mandal

Buildings are significant consumers of energy and producer of greenhouse gases worldwide, and serious efforts have been put into designing energy-efficient buildings. Significant technological advances have been achieved in developed countries; however, advances have rarely been adopted in developing countries like Afghanistan. Such trends emerge from the lack of research in designing energy-efficient buildings to local conditions, practices and materials. This research focused on building energy modelling and simulation to evaluate the energy performance impact of different shading and orientation. The research design follows a case study over an actual seven-storey multi-apartment residential building in the city of Mazar-I-Sharif, Afghanistan, using primary field data and dynamic simulation. Findings demonstrated that neighbouring structures have a positive correlation with a cooling demand. Meanwhile, south is the optimal orientation to face the building's glazed façade, saving up to 7.4% of cooling and 9.7% of heating energy. Moreover, movable shading devices installed on the building's openings in the summer season reduce the building energy load up to 19%, with a total energy cost reduction of AFN. 188,448 ($2447.37 US) annually. The study underlines the vast research scope in customizing building designs to Afghanistan's climatic conditions and other developing countries, thus contributing to buildings’ sustainability.


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.


2020 ◽  
Vol 12 (16) ◽  
pp. 6372
Author(s):  
Christine Eon ◽  
Jessica K. Breadsell ◽  
Joshua Byrne ◽  
Gregory M. Morrison

Energy efficient buildings are viewed as one of the solutions to reduce carbon emissions from the built environment. However, studies worldwide indicate that there is a significant gap between building energy targets (as-designed) and the actual measured building energy consumption (as-built). Several underlying causes for the energy performance gap have been identified at all stages of the building life cycle. Focus is generally on the post-occupancy stage of the building life cycle. However, issues relating to the construction and commissioning stages of the building are a major concern, though not usually researched. There is uncertainty on how to address the as-designed versus as-built gap. The objective of this review article is to identify causes for the energy performance gap in buildings in relation to the post-design and pre-occupancy stages and review proposed solutions. The methodology applied in this research is the rapid review, which is a variant of the systematic literature review method. Findings suggest that causes for discrepancies between as-designed and as-built energy performance during the construction and commissioning stages relate to a lack of knowledge and skills, lack of communication between stakeholders and a lack of accountability for building performance post-occupancy. Recommendations to close this gap during this period include better training, improved communication standards, collaboration, energy evaluations based on post-occupancy performance, transparency of building performance, improved testing and verification and reviewed building standards.


2020 ◽  
Vol 15 (2) ◽  
pp. 180-189
Author(s):  
Ibrahim Rizk Hegazy

Abstract Current research pays special attention to the application of approaches that promote sustainable design in a built environment and ensure energy efficiency. In this context, the form of housing buildings is an important parameter that has a meaningful impact on the use of energy in housing buildings. Hence, this research attempts to study the impact of the form of housing buildings on energy efficiency taking into account the mid-hot weather conditions in one of the middle-income housing buildings in new communities in Egypt. To achieve the research aim, a comparative analysis is carried out using parametric numerical analysis—DesignBuilder energy analysis—to compare the various hypothetical proposals for different building configurations. The study determines that the efficiency of energy use in buildings depends to a large extent on their forms that will help urban designers and planners to propose the best energy performance in the form of housing buildings in the stage of conceptual design suitable for other environmental, social and economic urban planning issues. These results should be incorporated into the building codes adopted in Egypt’s new cities in order to reach more energy-efficient housing buildings in Egypt.


2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pyeongchan Ihm ◽  
Moncef Krarti

Optimal and cost-effective energy efficiency design and operation options are evaluated for office buildings in Tunisia. In the analysis, several design and operation features are considered including orientation, window location and size, high performance glazing types, wall and roof insulation levels, energy efficient lighting systems, daylighting controls, temperature settings, and energy efficient heating and cooling systems. First, the results of the optimization results from a sequential search technique are compared against those obtained by a more time consuming brute-force optimization approach. Then, the optimal design features for a prototypical office building are determined for selected locations in Tunisia. The optimization results indicate that utilizing daylighting controls, energy efficient lighting fixtures, and low-e double glazing, and roof insulation are required energy efficiency measures to design high energy performance office buildings throughout climatic zones in Tunisia. In particular, it is found that implementing these measures can cost-effectively reduce the annual energy use by 50% compared to the current design practices of office buildings in Tunisia.


2019 ◽  
Vol 11 (6) ◽  
pp. 1672 ◽  
Author(s):  
Ali Amiri ◽  
Juudit Ottelin ◽  
Jaana Sorvari

Depletion of natural resources and climate change are undoubtedly the biggest challenges that humankind faces today. Here, buildings have a crucial role since they consume the majority, i.e., 30% to 40% of the total energy resources. Green building certification is one of the solutions to limit the energy use in buildings. In addition, it is seen to indicate a consideration for sustainability aspects in construction. LEED is the most widely used certificate worldwide. However, recently some critics have raised doubts about LEED and whether it actually implies sustainability. Most of the criticism has been targeted to the energy aspects of LEED. Nevertheless, there is no consensus on the usefulness of LEED: is it really beneficial for the environment, and is it worth of the money and time invested on the certification process? In this study a critical analysis of the literature to find an answer to this question is presented. Altogether 44 peer reviewed articles dealing with the abovementioned issue were selected out of 164 search result. Based on the studied material, the different aspects of LEED from the viewpoint of energy-efficiency are discussed. From the 44 reviewed articles, ten articles state that LEED certificate indicates energy efficiency while eight papers end up with an opposite conclusion. The rest of the papers do not take any stand on this matter. The study showed that energy efficiency of LEED-certified buildings is questionable especially at lower levels, i.e., certified. Therefore, it is recommended to modify the Energy and Atmosphere category of LEED in order to improve the actual energy performance of buildings.


Author(s):  
Filipe O Cunha ◽  
Armando C Oliveira

Abstract Hotels hold an important role in the energy efficiency policies of the European Union (EU), as they are typically ranked among the top energy consumers in the non-residential sector. However, a significant amount of the energy used in hotels is wasted, leaving ample room for enhancing energy-efficiency and resource conservation. Indeed, energy refurbishment of the hotel building stock is crucial in order to reach the nearly zero energy building (nZEB) status imposed by EU Directives for energy efficiency, and also an important pillar to achieve the energy targets for 2030 and the transition towards climate-neutral levels by 2050. A typical 4-star hotel in operation in Faro (Portugal) was used as a case study in order to establish energy performance indicators for nZEB hotels in three European cities, taking into account the influence of the climatic context, the technical feasibility and cost effectiveness of the best energy retrofit packages. The study started after the calibration of the building energy model by means of an energy audit and measured data, in order to have a baseline model that represents well the actual energy use of the hotel in the reference location. The building energy model was developed by using DesignBuilder/EnergyPlus software. The validated model was then used to assess the effect of the best retrofit interventions (energy efficiency measures and active solar systems) in order to set minimum energy performance requirements and to reach cost-optimal levels and nZEB levels for refurbished hotels. A significant energy-saving potential was found for the cost-optimal benchmarks, and the obtained nZEB levels can be achieved under technically and economically conditions for the selected cities: Faro, London and Athens.


2019 ◽  
Vol 111 ◽  
pp. 03073
Author(s):  
Cristina Tanasa ◽  
Cristina Becchio ◽  
Stefano Paoloc Corgnati ◽  
Valeriu Stoian ◽  
Daniel Dan

Building energy modelling and simulations play an important role in the design of energy efficient buildings but also in post-construction phases for commissioning, operation and optimization. With the use of data from monitoring systems related to the operation conditions of a building, calibrated simulations can be performed that accurately follow the real energy performance of a building. This paper present a procedure to achieve a calibrated building energy model simulation using monitoring data. The aim of the study is to verify/validate the results of the building energy model simulation against measured data. The study is based on an existing highly energy efficient building, which is continuously monitored in terms of energy consumptions and environmental parameters for several years now. The performance of the building energy model was assessed using statistical indices. The monthly total energy consumption comparison between simulated and measured shows that the building energy model managed to predict very closely the measured values. The accuracy of the building energy model in predicting air temperature was assessed as well.


Author(s):  
V. Deshko ◽  
I. Bilous ◽  
N. Buyak ◽  
O. Petruchenko

Global trends of increasing the buildings energy efficiency are aimed at reducing energy use to nearly zero consumption (nZEB). Achieving the nZEB level requires the implementation of a set energy-saving measures to improve the thermophysical properties of fences, building engineering systems and the use of renewable energy sources. One of low-cost and energy-efficient measures to increase the level of energy efficiency of buildings is the introduction of energy-efficient intermittent heating modes of buildings. Usually, this measure is appropriate and possible after the thermal modernization of the building. Determining the energy performance of buildings for the introduction of intermittent heating modes requires the use of mathematical models. The paper compares the application of different mathematical models and methods for estimating thermal energy savings in thermal modernization and implementation of intermittent heating modes based on the quasi-stationary model according to DSTU B A.2.2-12: 2015, stadium model created on the basis of RETScreen software and dynamic model 5R1C according to EN ISO 13790 and EN 13786. Heat-accumulation properties of building enclosures in RETScreen are not taken into account, in DSTU B A.2.2-12: 2015 - are taken into account for external enclosures, 5R1C - both internal and external enclosures are taken into account. The calculation was made for a residential building and a gymnasium located in the city of Kyiv. The introduction of a set of measures for thermal modernization of building fences will reduce heat consumption by 60 and 35% for residential building reinforced and gymnasiums, respectively. Introduction of intermittent heating modes for buildings after thermal modernization / modern buildings allows to save on heating more than 15% - determined on the basis of RETScreen program, 10% - on the basis of dynamic grid model 5R1C, 22% - on the basis of quasi-stationary method according to DSTU B A.2.2- 12: 2015, for a residential building and a gymnasium building located in Kyiv.


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