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Building energy models (BEMs) are typically used for design and code compliance for new buildings and in the renovation of existing buildings to predict energy use. The increasing adoption of BEM as standard practice in the building industry presents an opportunity to extend the use of BEMs into construction, commissioning and operation. In 2009, the authors developed a real-time simulation framework to execute an EnergyPlus model in real time to improve building operation. This paper reports an enhancement of that real-time energy simulation framework. The previous version only works with software tools that implement the custom co-simulation interface of the Building Controls Virtual Test Bed (BCVTB), such as EnergyPlus, Dymola and TRNSYS. The new version uses an open standard interface, the Functional Mockup Interface (FMI), to provide a generic interface to any application that supports the FMI protocol. In addition, the new version utilizes the Simple Measurement and Actuation Profile (sMAP) tool as the data acquisition system to acquire, store and present data. This paper introduces the updated architecture of the real-time simulation framework using FMI and presents proof-of-concept demonstration results which validate the new framework. [ABSTRACT FROM AUTHOR]

Abstract Parallel fan-powered terminal units (FPTUs) are widely considered more energy efficient compared with series FPTUs because of the intermittent terminal unit fan operation. Recent studies found that the energy savings potential of parallel FPTUs may be overestimated due to the primary air leakage through the backdraft dampers when terminal unit fans are not operating. However, the lack of an effective modeling approach in building simulation programs has prevented the thorough investigation of how the primary air leakage from parallel FPTUs affects the energy consumption of variable air volume (VAV) systems. In this paper, a modeling approach was developed and implemented in EnergyPlus using the Energy Management System (EMS) for the comparative analysis of energy impact of primary air leakage from parallel FPTUs. A series of building energy simulations were also conducted at four air leakage levels under five different U.S. climates. Although the percentage energy increases caused by the primary air leakage vary with local climates and leakage levels, simulation results show consistent increases in the energy consumption of central cooling coil, central supply fan, and FPTU supplemental heating throughout all the climates as the air leakage level increases. Compared with series FPTUs, the energy savings potential of parallel units significantly decreases as air leakage level increases. At the highest air leakage level of 15% simulated in this study, series FPTUs may use less energy than parallel FPTUs. [ABSTRACT FROM AUTHOR]

The paper describes a study developed to estimate the energy savings potential of a radiant cooling system installed in a commercial building in India. To evaluate thermal performance and energy consumption, simulations were carried out using FLUENT and EnergyPlus software, respectively. The building model was calibrated using the measured data for the installed radiant system. Then this calibrated model was used to simulate the energy consumption of a building using a conventional all-air system to determine the proportional energy savings. For proper handling of the latent load, a Dedicated Outside Air System (DOAS) was used as an alternative to Fan Coil Unit (FCU) that was installed in conjunction with the radiant cooling system. A comparison of energy consumption calculated that the radiant system was 17.5% more efficient than a conventional all-air system and that a 30% savings was achieved by using a DOAS system compared with a conventional system. The Computational Fluid Dynamics (CFD) simulation showed that a radiant system offers more uniform temperatures, as well as a better mean air temperature range, than a conventional system. To further enhance the energy savings in the radiant system, different operational strategies were analyzed based on thermal analysis using EnergyPlus. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, calibrated energy modeling of residential and commercial buildings has gained importance in a retrofit-dominated market. Accurate weather data play an important role in this calibration process and projected energy savings. It would be ideal to measure weather data at the building location to capture relevant microclimate variation but this is generally considered cost-prohibitive. There are data sources publicly available with high temporal sampling rates but at relatively poor geospatial sampling locations. To overcome this limitation, there are a growing number of service providers that claim to provide real time and historical weather data necessary for building modeling at 15–40km2 grid across the globe; common variables such as temperature and precipitation have been constructed on ∼1km2 grids . Unfortunately, there is limited documentation from 3rd-party sources attesting to the accuracy of this data. This paper compares provided weather characteristics with data collected from a weather station inaccessible to the service providers. Monthly average dry bulb temperature; relative humidity; direct normal, diffuse and global solar radiation; wind speed and wind direction are statistically compared. Moreover, we ascertain the relative contribution of each weather variable and its impact on building loads. Annual simulations are performed for three different building types, including a closely monitored and automated energy efficient research building. The comparison shows that the difference for an individual variable can be as high as 90%. In addition, annual building energy consumption can vary by ±7% while monthly building loads can vary by ±40% as a function of the provided location''s weather data. [Copyright &y& Elsevier]

Abstract: The concern on climate change leads to growing demand for minimization of energy use. As building is one of the largest energy consuming sectors, it is essential to study the impact of climate change on building energy performance. In this regard, building energy simulation software is a useful tool. A set of appropriate typical weather files is one of the key factors towards successful building energy simulation. This paper reports the work of developing a set of weather data files for subtropical Hong Kong, taking into the effect of future climate change. Projected monthly mean climate changes from a selected General Circulation Model for three future periods under two emission scenarios were integrated into an existing typical meteorological year weather file by a morphing method. Through this work, six sets of future weather files for subtropical Hong Kong were produced. A typical office building and a residential flat were modeled using building simulation program EnergyPlus. Hourly building energy simulations were carried out. The simulated results indicate that there will be substantial increase in A/C energy consumption under the impact of future climate change, ranging from 2.6% to 14.3% and from 3.7% to 24% for office building and residential flat, respectively. [Copyright &y& Elsevier]

Abstract: Double skin façade can be defined as a building façade covering one or several stories with multiple skins. The skins may be air tight or ventilated. With sophisticated study and design, buildings constructed with double skin façade can have better thermal performance than the conventional single skin façade. This paper reports the findings on the energy performance of double skin façade applied to a typical office building under the climatic condition in Hong Kong. An experimental setup was established and the measured data were used to verify the theoretical model developed via the EnergyPlus simulation program. The validated model was then used to evaluate the energy performance of double skin façade with various configurations including glazing type (clear, absorptive or reflective glass), glazing position (inner or outer pane) and glazing layers (single or double glazing material). The results indicate that a double skin façade system with single clear glazing as the inner pane and double reflective glazing as the outer pane can provide an annual saving of around 26% in building cooling energy, as compared to a conventional single skin façade with single absorptive glazing. However, the long payback period of 81 years makes the double skin façade system economically infeasible. Support and motivation are needed from the local government in order to foster successful and widespread application of the double skin façade system in buildings. [Copyright &y& Elsevier]

[Display omitted] • Developed an R package that integrates EnergyPlus with data-driven analytics. • Structured inputs/outputs format that can be easily piped into data analytics workflows. • Facilitates reproducible simulations through Docker. • Enables flexible and extensible parametric simulations. Building energy simulation (BES) has been widely adopted for the investigation of building environmental and energy performance for different design and retrofit alternatives. Data-driven analytics is vital for interpreting and analyzing BES results to reveal trends and provide useful insights. However, seamless integration between BES and data-driven analytics current does not exist. This paper presents eplusr, an R package for conducting data-driven analytics with EnergyPlus. The R package is cross-platform and distributed using CRAN (The Comprehensive R Archive Network). With a data-centric design philosophy, the proposed framework focuses on better and more seamless integration between BES and data-driven analytics. It provides structured inputs/outputs format that can be easily piped into data analytics workflows. The R package also provides an infrastructure to bring portable and reusable computational environment for building energy modeling to facilitate reproducibility research. [ABSTRACT FROM AUTHOR]

• Future-TMY (F-TMY) and Morphing methodologies are compared in 14 Iberian cities. • Morphing sensitive analysis using 3 different files is performed. • High-quality Morphing and F-TMY have similar climate and BES performances (7%−8%). • F-TMY is representative of the multi-year simulation for BES applications. • Low-quality Morphing leads to average errors between 16% to 20%. In the last decade, building energy simulation (BES) became a central component in building energy systems' design and optimization. For each building location, BES requires one year of hourly weather data. Most buildings are designed to last 50+ years, consequently, the building design phase should include BES with future weather files considering climate change. This paper presents a comparative study of two methods to produce future climate hourly data files for BES: Morphing and typical meteorological year of future climate (F-TMY). The study uses data from a high-resolution (9 km) regional climate atmospheric model simulation of Iberia, spanning 10 years of historical and future hourly data. This study compares both methods by analyzing anomalies in air temperature, and the impact in BES predictions of annual and peak energy consumption for space heating, cooling and ventilation in 4 buildings. Additionally, this study performs a sensitivity analysis of morphing method. The analysis shows that F-TMY is representative of the multi-year simulation for BES applications. A high-quality Morphed TMY weather file has a similar performance compared to F-TMY (average difference: 8% versus 7%). Morphing based on different baseline climates, low-grid resolution and/or outdated climate projections leads to BES average differences of 16%-20%. [ABSTRACT FROM AUTHOR]