Changes In Energy Performance Research Articles

The effect of window design factors on the cooling load in hospitals wards

PurposeThis paper investigates the optimization of window design factors (WDFs) in hospital buildings, particularly in government hospitals within the arid climate of the Qassim region, with the aim of achieving a better cooling load reduction. Continuous monitoring of the hospital ward section is crucial due to patients' needs, requiring optimal indoor air quality and cooling load.Design/methodology/approachThe study identifies the optimal conditions for WDF design to mitigate cooling load, including window-to-wall ratio (WWR), window orientation (WO), room size and U-value (thermal properties), effectively reduce energy consumption in terms of sensible cooling load (MWh/m2) and comply with local codes. Data collection involved a smart weather station, while the Integrated Environmental Solution Virtual Environment (IESVE) software facilitated the simulation process.FindingsKey findings reveal that larger patient rooms were about 40% more energy-efficient than smaller rooms. The northern orientation showed lower energy consumption, and specific WWRs and glazing U-values significantly affected energy loads. In an analysis of U-value changes in energy performance based on the Saudi Building Code (SBC), the presented values did not meet the minimum energy consumption standards. For a valid 40% WWR with a thermal permeability of 2.89, 0.181 MWh/m2 was consumed, while for an invalid 100% WWR with the same permeability but facing the north, 0.156 MWh/m2 was consumed, which is considered an invalid practice. It is vital to follow prescribed standards to ensure energy efficiency and avoid unnecessary costs.Originality/valueFocus lies in emphasizing the significance of adhering to prescribed standards, such as SBC, to guarantee energy efficiency and prevent unwarranted expenses. Additionally, the authors highlight the crucial role of optimizing glazing properties and allocating the WWR appropriately to achieve energy-efficient building design, accounting for diverse orientations and climatic conditions.

Evaluation of energy efficient building envelope alternatives for sustainable cities

This study is aimed to create an exemplary project to present the contribution of the new buildings to energy savings when the residential buildings are transformed into green buildings. To create a sustainable built environment in residences, this study emphasizes that low-energy building strategies be combined with efficient and high-performance natural-sourced materials. Our findings show that using a natural-sourced material as the building envelope material has an impact on the use of primary energy and energy costs of the alternatives studied. In this study; In the case of replacing the building external wall components of an existing construction designed with internal insulation in the climatic conditions of Ankara, the change in energy performance has been investigated. The analysis was done with the help of BIM-based Revit Program and “Green buildings studio” where energy simulations were created. In the study, 54 different wall combinations were created by modeling combinations of different construction (porous, gas concrete, and pumice bricks), insulation (glass wool, rock wool, sheep wool, PUR, XPS, and EPS) and, roof (tile, asphalt shingle, and green roof) materials. When the outputs obtained from the analyzes were evaluated, the lowest energy consumption values were observed in the combination of pumice brick wall, green roof, and polyurethane insulation materials. In this scenario, the annual fuel consumption per square meter is determined as 30000.6 MJ/m2. On the other hand, the highest energy consumption values were observed in the combination of porous brick wall, tile roof and sheep wool insulation materials. In this scenario, the annual energy consumption per square meter is determined as 30026.6 MJ/m2. Although there are not high numerical differences between the findings, it has been observed that the results give consistent results with the thermal conductivity coefficients of the materials used in the combinations.

Smart communities in Japan: Requirements and simulation for determining index values

Recently, smart communities are heeded to in Japan as a solution to community issues. To properly evaluate the underlying concept, it is necessary to analyze smart cities in terms of local energy and environmental aspects, as well as disaster resilience. This research aimed to summarize the requirements for Japanese smart communities, and provide this information to municipalities, city planners, and regional developers in warmer climates, or countries where few precedents exist. Nine cases were reviewed in Japan, and four in Europe and the US to organize smart community requirements into three areas: environment, social, and safety-security. Additionally, bottom-up simulations were used to quantitatively evaluate the effects of energy technology introduction, emergency Life Continuity Plans (LCPs), and changes in energy performance owing to household compositional differences. The results showed that a typical Japanese smart community (containing Fuel cell, PV, and battery) has the capacity to become a positive energy district, generating 1916 ​GJ ​yr−1, and maintain power throughout a one-week power outage if shared within the community (save for the highest temperature week in August). Conversely, Japanese smart communities lacked consideration of residential diversity and creative landscapes.

A step towards green economic policy framework: role of renewable energy and climate risk for green economic recovery

According to the World Bank, energy efficiency is a critical facilitator of most Sustainable Development Goals. Its contribution to CO2 emission reduction is astounding. Environmentalists have recently emphasized the essential need to determine energy efficiency causes. This research broadens the debate's horizons by proposing additional possible energy efficiency factors using data from the Chinese economy. From 1990 to 2020, we examined the influence of investment in renewable energy resources, financial inclusion, industrial production, and trade openness on China's energy efficiency and climate risk. Additionally, this study is added to the literature by examining the causal relationships between variables while considering the temporal dimension. The findings indicate that industrial production, financial inclusion, public R&D on renewable energy, and trade openness contribute significantly to China's energy efficiency and climate risk. All other factors, except industrial production, are positively associated with energy efficiency. The path of causality is established from energy efficiency and climate risk to financial inclusion, industrial production, renewable energy, public research and development budgets, and trade openness. According to the findings, changes in energy performance have frequency-changing impacts on all variables. Policymakers believe that the financial system must be strengthened since this will significantly influence renewable energy.

Potential Reconstruction Design of an Existing Townhouse in Washington DC for Approaching Net Zero Energy Building Goal

The concept of the Net Zero Energy Building (NZEB) has received more interest from researchers due to global warming concerns. This paper proposes to illustrate optional solutions to allow existing buildings to achieve NZEB goals. The aim of this study is to investigate factors that can improve existing building performance to be in line with the NZEB concept and be more sustainable. An existing townhouse in Washington, DC was chosen as the research target to study how to retrofit or reconstruct the design of a building according to the NZEB concept. The methodology of this research is modeling an existing townhouse to assess the current situation and creating optional models for improving energy efficiency of the townhouse in Revit and utilising renewable energy technology for energy supply. This residential building was modeled in three versions to compare changes in energy performance including improving thermal efficiency of building envelope, increasing thickness of the wall, and installing smart windows (switchable windows). These solutions can reduce energy and cost by approximately 8.16%, 10.16%, and 14.65%, respectively, compared to the original townhouse. Two renewable energy technologies that were considered in this research were photovoltaic and wind systems. The methods can be applied to reconstruct other existing buildings in the future.

The renewing of Energy Performance Certificates—Reaching comparability between decade-apart energy records

Energy Performance Certificates are currently one of the most extensive data sources about the energy performance of the EUs building stock and consequently provide support for researchers and policy makers in energy regulation. As Energy Performance Certificates are being renewed, there are new possibilities to study energy performance development over time and to evaluate the building-specific effect of energy policies and measures. This paper aims to explore this possibility. In Sweden, owners of multifamily buildings had to obtain their first Energy Performance Certificate no later than the end of 2008, and with a period of validity of 10 years many owners have now obtained a second Energy Performance Certificate for their building(s). This enables unprecedented quantitative, building-specific evaluations of the change in energy performance over time. However, comparability between old and new Energy Performance Certificates must be assured. This study develops a novel three-step method to attain comparability between old and renewed Energy Performance Certificates. Results show that while many pairs of Energy Performance Certificates were considered comparable, procedural changes in methods for determining heated floor area in Swedish Energy Performance Certificates caused an overestimation of energy performance improvement of approximately 7 kWh/m2 per building which had to be corrected for. The results of this paper indicate that old and renewed Energy Performance Certificates can be utilised to successfully map development of energy performance and enable evaluation of the impact on energy performance from policies and measures that have been carried out between the two points of audit.

Development of building thermal environment emulator to evaluate the performance of the HVAC system operation

A “performance gap” arises when the actual value of building energy consumption during the operational phase deviates from the value predicted using simulation during the design phase. One cause of this performance gap is that operation is not ideal, as assumed in the simulation, and the control of the heating, ventilating, and air conditioning (HVAC) system is not optimized. These problems occur because the operator has not been trained sufficiently and/or the building automation system is not working as intended by the developer. Both problems are fundamentally caused by the fact that the quality of building operation cannot be quantitatively evaluated by comparison with other buildings because a building is a heterogenous, single-item product. To address the performance gap problem, we developed a method for quantitatively evaluating building operation using a precise simulation based on a thermal environment emulator. The emulator software was developed using the BACnet protocol as an interface to the real world and includes an occupant behavior model to enable the assessment of operation in terms of thermal comfort as well as energy performance. In this paper, we report on the program and network structure of the proposed emulator. In addition, we show the concrete results of changing the operational control, and we assess changes in energy performance and comfort from the perspective of Pareto efficiency.

Measuring plant level energy efficiency and technical change in the U.S. metal-based durable manufacturing sector using stochastic frontier analysis

This study analyzes the electric and fuel energy efficiency for five different metal-based durable manufacturing industries in the United States over the time period 1987–2012, at the 3 digit North American Industry Classification System (NAICS) level. Using confidential plant-level data on energy use and production from the quinquennial U.S. Economic Census, a stochastic frontier regression analysis (SFA) is applied in six repeated cross sections for each five year census. The SFA controls for energy prices and climate-driven energy demand (heating degree days HDD and cooling degree days CDD) due to differences in plant level locations, as well as 6-digit NAICS industry effects. Own energy price elasticities range from −0.7 to −1.0, with electricity tending to have slightly higher elasticity than fuel. Mean efficiency estimates (100% = best practice level) range from a low of 33% (fuel, NAICS 334 - Computer and Electronic Products) to 86% (electricity, NAICS 332 - Fabricated Metal Products). Electric efficiency is consistently better than fuel efficiency for all NAICS. Assuming that all plants in the least efficient quartile of the efficiency distribution achieve a median level of performance, we compute the decline in total energy use to be 21%. A Malmquist index is used to decompose the aggregate change in energy performance into indices of efficiency and frontier (best practice) change. Modest improvements in aggregate energy performance are mostly change in best practice, but failure to keep up with the frontier retards aggregate improvement. Given that the best practice frontier has shifted, we also find that firms entering the industry are statistically more efficient, i.e. closer to the frontier; about 0.6% for electricity and 1.7% for fuels on average.

ENERGY PERFORMANCE OF THE EDUCATIONAL BUILDING ENVELOPE ACCORDING TO A PASSIVE AND LOW-ENERGY STANDARD

<jats:p>High energy demands and obligation for building energy certification make an impact on architectural design and building construction. The paper aims to present energy performance of the educational building envelope in a passive and low-energy standard in the climatic conditions of the north zone of the Republic of Srpska (Bosnia and Herzegovina). The case study of design project for the building of Faculty of Architecture, Civil engineering and Geodesy, which construction started in 2011 in Banja Luka, serves as the basis for the presented research . The original plan for passive educational building development required large investments, which unfortunately were not provided. Planned 179construction costs with new concept were reduced, not only with lower requirements of the envelope energy performance, but also technical systems such as heating type, lower costs on finishing layers of floors, furnishing etc. The paper presents changes in energy performance of the building envelope and its impact on transmission and ventilation heat losses, as well as the energy needs for heating.</jats:p>

Change in energy performance as a result of a R422D retrofit: An experimental analysis for a vapor compression refrigeration plant for a walk-in cooler

In this paper, the energy performance of a walk-in cooler working with R22 and its substitute R422D are experimentally studied. The experimental investigation was carried out considering three different operating conditions; in particular, the AHRI standard has been used as reference for operating conditions. All tests were run at steady state conditions and keeping the external air temperature at 35 °C. The experimental analysis allowed the determination of cooling capacity, the electrical power absorbed, the COP and other variables characterizing the working of the plant. The results demonstrated that the cooling capacity for R422D was lower than for R22, while the electrical power absorbed with R422D was higher than that with R22. As consequence, the COP of R422D was lower than that of R22. Furthermore, technical proposals are introduced with the aim of improving the overall performances of those plants, which could be retrofitted with R422D.