Packages Of Energy Efficiency Measures Research Articles

DETERMINATION OF OPTIMAL PACKAGES OF ENERGY EFFICIENT MEASURES FOR PUBLIC BUILDINGS

The paper is devoted to the problem of improving the energy efficiency of public buildings maintained with funds from the state and/or local budgets. Optimization modeling is proposed as an instument to determine the optimal packages of energy efficiency measures according to the criterion of maximum achieved savings of fuel and energy resources. Approbation of the mathematical model on actual data has shown its practical value - depending on a given budget, the optimal packages of energy efficiency measures for public buildings (on the example of Zaporizhzhia city) are determined. Based on the results of computational experiments, energy efficiency measures with the best and worst ratios of implementation costs and achieved savings of fuel and energy resources were identified. The impact of additional constraints on the composition of an optimal package of energy efficiency measures was shown to make informed and rational decisions on investing in energy efficiency improvement projects for public buildings.

The application of EN ISO 52016-1 to assess building cost-optimal energy performance levels in Italy

In Italy, the cost-optimisation calculation procedure, based on the comparative methodology framework established by the Commission Delegated Regulation 244/2012 to derive minimum energy performance requirements of buildings, was firstly applied by means of a monthly quasi-steady-state calculation method based on EN ISO 13790. The introduction of the new EN ISO 52016-1 simplified hourly calculation method determined the possibility of testing the new assessment procedure. The aim of this work is to analyse the deviation between the monthly and hourly calculation methods in the assessment of the building energy needs for space heating and cooling and in the selection of cost-optimal solutions. The cost-optimisation analysis was hence performed on a group of buildings representative of the Italian building stock. The results of the monthly and hourly methods in terms of cost-optimal levels and packages of energy efficiency measures were then compared. Results show limited variations in the resulting global cost, while differences in the cost-optimal packages of energy efficiency measures are not negligible. A sensitivity analysis of the main economic parameters was carried out, pointing out the main influencing factors.

Energy efficiency package for rooftop unit replacement: laboratory testing and validation of energy savings

Over half of commercial building floor area in the US is served by packaged rooftop units (RTUs). With a typical useful life in the 10-20 years range, RTU replacement is a periodic necessity in commercial buildings and an opportunity for upgrading to higher-efficiency units. We designed a package of energy efficiency measures that can be used in conjunction with an RTU replacement, including advanced controls, high-efficiency low pressure-drop air filters, energy monitoring and, optionally, window films and cool-roofs to reduce loads and size of the replacement RTUs. We conducted side-by-side laboratory testing of the package to evaluate energy savings and thermal comfort relative to an existing building baseline. Daily HVAC energy savings for the RTU replacement package averaged 61% across all seasons. The test data showed that the ASHRAE Guideline 36 controls significantly reduced thermal loads and this was a key contributor to the savings, in addition to the higher efficiency of the RTU itself. The laboratory testing also revealed some challenges with installation and commissioning of Guideline 36. Overall, the results demonstrate that significant savings can be realized in existing office buildings by incorporating relatively low-risk, proven measures in conjunction with an RTU replacement.

Energy Efficiency Package for Tenant Fit-Out: Laboratory Testing and Validation of Energy Savings and Indoor Environmental Quality

Approximately 40% of the total U.S. office floor space of 1.5 billion sq.m (16 billion sq.ft.) is leased space occupied by tenants. Tenant fit-out presents a key opportunity to incorporate energy efficiency within the real estate business cycle. We designed a package of energy efficiency measures tailored to the scope of a tenant fit-out. This tenant fit-out package (TFP) includes advanced lighting and heating, ventilating and air-conditioning (HVAC) controls as core measures, with ceiling fans, automated shading, and plug load controls as additional optional measures. We conducted laboratory testing of six configurations of the package to evaluate energy savings, indoor environmental quality, and identify installation, commissioning, and operational issues. Combined savings for HVAC, lighting, and plug loads ranged from 33–40%. Lighting savings ranged from 69–83%, and HVAC savings from 20–40%. The laboratory testing also revealed some minor but tractable challenges with installation and commissioning of HVAC controls. Overall, the results demonstrate that significant savings can be realized in existing office buildings by incorporating relatively low-risk, proven measures at the time of a tenant fit-out.

Energy efficiency optimisation in industrial processes: Integral decision support tool

Assessing and improving energy efficiency in manufacturing processes is a crucial issue for companies who wish to become competitive. In addition, there are high margins of technical energy efficiency improvement for practically each sector and kind of industry. There are many Energy Efficiency Measures (EEM)s and tools in the literature to assess energy efficiency. To fit an EEM to a specific process is a complicated task, due to the different characteristic and restrictions of each specific manufacturing process. Owing to the complexity of the non-continuous processes, each measure has to be deeply analysed. Consequently, this work presents an integral analysis, process optimisation and decision support tool to assess the implementation of EEMs in these processes. This tool allows us to analyse both the possible synergies that may be created among the EEMs and their impact on other parts of the process line. The optimum solution or combination of EEMs, and their sizing, are determined to reach the highest levels of energy efficiency. The impact on the overall energy efficiency and the synergies among EEMs is shown. Several packages of EEMs are analysed, with energy consumption reductions ranging from 21% to 50%.

Energy for off-grid homes: Reducing costs through joint hybrid system and energy efficiency optimization

This paper develops a new process for identifying the lowest cost package of energy efficiency measures (EEM) and hybrid energy system configuration for off-grid homes. Hybrid energy systems, which combine two or more types of energy technologies, often require significant capital expenditure, however, the cost can be reduced by applying EEM to the house to decrease energy demand. The method proposed here, termed Combined Optimization Process (COP), was tested on an off-grid hypothetical case and incorporates an iterative assessment of a building energy and efficiency optimization tool (BEopt) and a hybrid system optimization tool (HOMER). The COP results were compared with the base case where no efficiency measures were applied, and also with a standard process, which involved a selection of best-practice efficiency measures. The COP method yielded net present cost savings of 10% less than the base case, and 5% less than the standard process. The COP method developed in this paper is applicable for existing houses converting to off-grid status as well as for the design stage of off-grid houses.

University building: Energy diagnosis and refurbishment design with cost-optimal approach. Discussion about the effect of numerical modelling assumptions

The paper discusses a methodological approach for designing energy refurbishment measures basing on a deep energy diagnosis with in-situ measurements that allow the complete characterizations of building /HVAC system and the indoor conditions. Then, the Cost-Optimal approach is applied to compare several retrofit scenarios considering interventions both on the building envelope and on plant systems. The case study is a University building in heating dominated climate of South Italy. According to a macroeconomic perspective, with a discount rate of 3%, the package of energy efficiency measures that combines installation of heat recovery systems, regulation dispositive for HVAC and LED lamps with automatic control induces considerable energy saving and reduction of polluting emissions (−33%) as well as the largest reduction in the overall cost (−35%).Moreover, the importance to use validated models is examined exhaustively by proposing a sensitivity analysis on uncertainties due to modelling assumptions mainly referring to the adoption of stochastic schedules for occupant behaviour and equipment or lighting usage. First of all, this analysis shows that the calibration indexes are always dissatisfied; besides it is demonstrated that refurbishment design can appear more convenient, with wrong assumptions. For instance, one of proposed scenario brings to energy saving of −41% and reduction of global cost of around −36%.

Assessment of Cost Optimal Solutions for High Performance Multi-family Buildings in Iran

According to the international benchmarks proposed for the energy demand reduction, the Iranian government, for limiting domestic energy demand growth, has set some energy efficiency policies. In this regard, the present study proposes various solutions to investigate the feasibility of improving the performance of an existing typical multi-family building in Iranian context, to achieve a high performance one with proper cost-optimal levels of energy performance by using the global cost approach defined by EU legislation. Precisely 50 different packages of energy efficiency measures were analyzed in terms of economic and energy performance with consideration on the effects of different envelope thermal insulation, shading system, window types and highly efficient systems in addition to the solar renewable energy source. Then the impact of the selected measures on energy efficiency improvement and global cost were studied and revealed that obtaining high performance building simultaneously with the cost optimal levels can be fulfilled, just when the financial support from the government subsidies exist, otherwise there is still a long way from being economically feasible.

On the Refurbishment of the Public Building Stock Toward the Nearly Zero-energy Target: Two Italian case studies

The study presents some results of the on-going European Project, RePublic_ZEB, on the refurbishment of the public building stock towards nearly Zero Energy Building (nZEB). The work is focused on the application of the nZEB requirements to two existing public buildings representative of the 1960s in Northern Italy. Many packages of energy efficiency measures that comply with nZEB requirements are identified and evaluated. The aim is to promote energy efficient but also cost-effective solutions for the Italian building stock refurbishment. The results are presented in terms of «package of measures», energy consumption, global costs, actualized pay-back period and CO2 emission.

LCC assessments and environmental impacts on the energy renovation of a multi-family building from the 1890s

The 2020 and 2050 energy targets increase requirements on energy performance in the building stock, thus affecting both listed and non-listed buildings. It is important to select appropriate and cost-optimal energy efficiency measures, using e.g. Life Cycle Cost (LCC) optimization. The aim of this paper is to find cost-optimal packages of energy efficiency measures (EEMs) as well as to explore the effects of specific predesigned energy target values for a listed Swedish multi-family building from the 1890s. The purpose is also to show the effects on energy use, LCC, primary energy use and CO2 emissions of different energy targets, discount rates, electricity prices and geographic locations. The results show that separate energy targets could be an effective way to simplify the implementation for listed buildings. Furthermore, a cost-optimal package of EEMs is more sensitive to changes in discount rate than in electricity price. The energy renovation has impact on the primary energy use and CO2 emissions. The lower the discount rate is, the more EEMs will be implemented and the easier the national energy targets may be achieved. A higher electricity price also leads to more EEMs being implemented but at the same time higher running costs.

Design the refurbishment of historic buildings with the cost-optimal methodology: The case study of a XV century Italian building

In order to deliver the European energy and climate objectives to 2050, significant changes are essential in the building sector, especially regarding the existing stock. Indeed, there is a huge potential for action, also regarding historic buildings. In this regard, today the question is: how to combine the building protection requirements and the application of energy efficiency measures?This paper tries to answer, evaluating if the refurbishment of historic architectures, in order to achieve very low energy need, is possible and economically feasible. More in detail, the applicability of the cost-optimal methodology (EPBD Recast 2010/31/EU) for historic buildings is discussed, by adopting the macroeconomic perspective, in order to take into account of the energy, environmental and economic impacts of about 60 packages of energy efficiency measures. The study is aimed to introduce a methodological approach to define reference buildings for historic architectures, through in-situ investigation of structural and energy peculiarities and, as real case study, the refurbishment of an Italian building of the XV century is presented. Moreover, guidelines are proposed to properly select energy efficiency measures, according to a point of view of cost-optimality. Conservation, aesthetical requirements, structural and energy issues are considered, as well as the incidence of all economic factors.

A new methodology for cost-optimal analysis by means of the multi-objective optimization of building energy performance

The recast version of the Energy Performance of Buildings Directive (2010/31/EU) proposes a comparative methodology aimed at defining the energy performance of buildings “with a view to achieving cost-optimal levels”. Really, how can the cost-optimal technologies be detected? Moreover, how can the most proper packages of energy efficiency measures be chosen in order to obtain the cost-optimality? This paper would provide answers to these questions, by proposing a new methodology for the evaluation of the cost-optimality, by means of the multi-objective optimization of energy performance of buildings and indoor thermal comfort. The optimization procedure is developed by means of the coupling between MatLab and EnergyPlus, by implementing a genetic algorithm, and it allows the evaluation of profitable and feasible packages of energy efficiency measures applied to buildings. Then, following the adoption of these packages, the global cost over the lifecycle of the building is calculated, in order to identify the cost-optimal solution. After the presentation of the methodology, the developed method is proposed for the optimization of the energy retrofit of an existing building. Furthermore, the method can be applied also for new architectures, by considering reference buildings.

Optimal design of residential building envelope systems in the Kingdom of Saudi Arabia

In this paper, a comprehensive analysis study is presented in order to improve the energy performance of residential buildings in the Kingdom of Saudi Arabia (KSA) through optimizing the building envelope elements. The building envelope energy conservation measures included in the study are wall insulation, roof insulation, window area, window glazing, window shading, and thermal mass. The optimization process was based on life cycle cost and energy savings. Optimum packages of energy efficiency measures for a residential building located in five climate zones in KSA have been determined for subsidized and non-subsidized energy costs. The results showed optimal energy savings of 39.5%, 33.7%, 35%, 32.7% and 22.7% for Riyadh, Jeddah, Dhahran, Tabuk and Abha, respectively, can be obtained for the subsidized energy cost case. For the non-subsidized energy cost case, the optimal energy savings were 47.3%, 41.5%, 43.19%, 41.1% and 26% for Riyadh, Jeddah, Dhahran, Tabuk and Abha, respectively. Moreover, a sensitivity cost analysis indicated that the cost of energy has more influence on optimal energy savings and life cycle costs than the initial costs of the energy efficiency measures. Finally, this study concluded that substantial savings in annual energy costs subsidies can be achieved by the KSA government if it aggressively promotes, through investments and incentives, energy efficiency programs for both existing and new buildings.

Specifying residential retrofit packages for 30 % reductions in energy consumption in hot–humid climate zones

The purpose of this research was to demonstrate the application of energy simulation as an effective tool for specifying cost-effective residential retrofit packages that will reduce energy consumption by 30 %. Single-family homes in the hot–humid climate type of the Southeastern USA were used to demonstrate the application. US census data from both state and federal studies were used to create 12 computer simulation homes representing the most common characteristics of single-family houses specific to this area. Well-recognized energy efficiency measures (EEMs) were simulated to determine their cumulative energy reduction potential. Detailed cost estimates were created for cost-to-benefit analysis. For each of the 12 simulated homes, 4 packages of EEMs were created. The four packages provided home owners options for reducing their energy by 30 % along with the estimated up-front cost and simple payback periods. The simple payback period was used to determine how cost-effective a measure was. The packages are specific to a geographic area to provide a higher degree of confidence in the projected cost and energy savings. The study provides a generic methodology to create a similar 30 % energy reduction packages for other locations and a detailed description of a case study to serve as an example. The study also highlights the value that computer simulation models can have to develop energy efficiency packages cost-effectively and specific to home owner’s location and housing type.

Lithuanian energy efficiency project

The combined efforts of active homeowners, private businesses, the project management unit, state authorities and international financing institutions led to successful implementation of the Energy Efficiency Housing Pilot Project in Lithuania. This project was aimed at supporting private and public initiatives to reduce energy use in residential and public buildings. This article presents major results and lessons which can be useful for future design of similar undertakings in neighboring Eastern European countries. Appropriate financing, workable legal framework, and extensive support network enabled more than 200 homeowners’ associations and owners of individual houses as well as 12 municipalities to implement various packages of energy efficiency measures in their buildings. Assistance from the project donors enhanced awareness and active participation of private businesses by increasing the capacity of local energy consulting services and establishing a network of regional advisory centers providing support for homeowners on technical, legal, financial and managerial issues. Technical monitoring of the implemented residential projects has demonstrated that comprehensive packages of energy efficiency measures can potentially save up to 50% of heat. Social monitoring of the project participants indicated the need for wide-ranging assistance to households and key stakeholders to stimulate changes in perceptions regarding energy efficiency through experiences in undertaking energy efficiency improvements.