Article

Thermal zoning for building HVAC design and energy simulation: A literature review

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Building energy simulation programs can be useful tools in evaluating building energy performance during a building's lifecycle, both at the design and operation stages. In addition, simulating building energy usage has become a key strategy in designing high performance buildings that can better meet the needs of society without consuming excess resources. Therefore, it is important to provide accurate predictions of building energy performance in building design and construction projects. Although many previous studies have addressed the accuracy of building energy simulations, very few studies of this subject have mentioned the importance of Heating, Ventilation, and Air-Conditioning (HVAC) thermal zoning strategies to sustainable building design. This research provides a systematic literature review of building thermal zoning for building energy simulation. This work also reviews previous definitions of HVAC thermal zoning and its application in building energy simulation programs, including those appearing in earlier studies of the development of new thermal zoning methods for simulation modeling. The results indicate that future research is needed to develop a well-documented and accurate thermal zoning method capable of assisting designers with their building energy simulation needs.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... For the flexible IEQ, several methods are used to keep the uniform ITC in cold weather conditions, the best known of which is a radiant heating system. In a radiant heating system, conventional radiators, ventilation radiators, underfloor heating, wall heating, intake air heating, and ceiling heating have been widely used with high efficiency [7]. IEQ is influenced by various factors that influence the perception of indoor comfort of the occupant; some of the most important factors are basal metabolic rate or occupant activity, clothing factor, air temperature, radiation temperature, operating temperature, air speed, and relative humidity. ...
... The k-ε turbulence model resolves Reynolds' averaged Navies-Stokes equation alongside calculations of turbulence kinetic energy production (k), its dissipation rate using the equations shown below (6,7) ∂ ∂t ∂ ∂t ...
Article
This study numerically analyses a well-validated comprehensive work on IEQ in a naturally ventilated, occupied 3-dimensional office building with installed furniture and internal heat-generating surfaces. This study analyzes the effect of the inlet diffuser orientation (IDO) on the indoor thermal comfort (ITC) of occupants and the energy demand of the building for heating indoor air. The Optimization of ITC has also been calculated for the acceptable indoor occupant comfort and energy consumption. The study is valuable to analyze the relationship between IDO of 0°, 15°, 30°, 45°, 60°and 75°, on ITC and the energy consumption of the indoor environment. Different methods have been chosen to study the ITC of the occupants such as air temperature, air movement in the occupied zone, vertical temperature gradient, and PMV and PPD index according to ISO7730. The results show that under a uniform indoor air distribution, the variation in IDO considerably affects the ITC and energy consumption. Optimized ITC can reduce indoor energy consumption by 35.14%. The IDO slightly affects the PMV and PPD index. Occupant's legs are more sensitive to the naturally ventilated indoor environment due to the adverse effect of buoyancy force which may create the problem of the cold draft. For optimization of the ITC, the air temperature in the occupied zone plays a key role.
... Coakley, Raftery, and Keane [51] recommend BES tools to assess the performance of key quality features during the building lifecycle. Shin and Haberl [52] stepped forward by reviewing HVAC thermal behavior operation using energy simulation software and concluded that this method could assist designers in their system planning. The research used the LEED-approved Cove.tool [53] as its energy simulation tool. ...
... The BES methodology acquires its reliability with the BEM qualities and is designed to simulate the Chinese standard office building's energy performance across several locations in different CZ. The literature review shows that BES methodology is frequently applied to assess buildings' energy performances in studies with purposes similar to our research [32,52]. The adopted prototype, developed by Feng et al. [49] and Feng and Levine [56], follows the PNNL-ASHRAE prototype building model methodology, upheld by the US Department of Energy. ...
Article
Full-text available
China promptly took the leading step to mitigate the spread of COVID-19, producing the first scientific guidelines assuming health above energy consumption and significantly changing HVAC/AHU operation. The research intended to fulfill the gap by measuring the impact of the guidelines on energy use intensity, CO2 emissions, and energy operation costs related to workplaces. The guidelines are long-term sector and industry trends following occupants' health and safety concerns, and today they are applied to nursing homes. The research extended the study to post-COVID-19 scenarios by crossing those settings with published reports on telework predictions. The methodology resorts to Building Energy Simulation software to assess the Chinese standard large office building on 8 climate zones and 17 subzones between pre-and post-COVID-19 scenarios under those guidelines. The outcomes suggest an upward trend in energy use intensity (11.70-12.46%), CO2 emissions (11.13-11.76%), and costs (9.37-9.89%) for buildings located in "warm/mixed" to "subarctic" climates, especially in colder regions with high heating demands. On the other hand, the figures for "very hot" to "hot/warm" climates lower the energy use intensity (14.76-15.47%), CO2 emissions (9%), and costs (9.64-9.77%).
... Only a few studies, however, investigate the impact of the degree of detail of the model on the simulation results. In this regard, the work of Gilani et al. [12] gives noteworthy attention to the influence of the user behaviour model, whereas [9], [13], [14] and [15] focus more on the influence of the zoning and shading simplification. In particular, M. Klimczak et al. in [9] analyse the effect of a gradual simplification of the building geometry on the results by disregarding shading elements and stepwise reducing the number of thermal zones, highlighting that shading elements on the south façade highly influence the results. ...
... The analysed variants are simulated using EnergyPlus and compared against a reference case and the deviations are evaluated in terms of heating demand and heating load. Similarly, the work of S. Elhadad et al. [13] shows Shin et al. [15] provides a literature review of building thermal zoning strategies and methods for building energy simulation and heating ventilation and air conditioning (HVAC) system design highlighting the lack of guidelines for the thermal zoning strategies. ...
Article
Full-text available
A large number of Building Energy Simulation (BES) tools with a different focus and degree of detail are available however, increasing the model complexity usually increases the modelling time and the number of required inputs, not always leading to better accuracy. Therefore it is important to find the trade-off between model complexity and computational time having in mind the purpose and goal of the simulation study and the available inputs. To shed some light on these aspects, different modelling approaches (i.e. thermal zone model, window model, thermal mass, etc…) are implemented using a cross-validated Simulink model of an office cell and the influence of each analysed aspect on the hourly results is addressed using the Goodness-of-fit and the computational time. As a result, it is observed that modelling the thermal zone with a two-star model leads to a good agreement with the surface-to-surface detailed radiation model in terms of energy balance and operative temperature in the centre of the room, but deviations are present when the temperature in a specific location of the room (e.g. near the window) has to be evaluated. In addition, it is found that a simplified thermal zone model such as one-star model allows important savings in terms of computational time, but leads to deviations in the dynamic behaviour. However, the energy balance can have an acceptable accuracy for specific applications when the inputs are calibrated. Regarding the window model, the results show that it strongly affects the accuracy of the simulation. Furthermore, many aspects that are often overlooked, such as the models of the adiabatic structure, sky model, capacity of the air node, distribution of the radiative gains to the surfaces of the enclosure and convective and radiative exchange coefficients, influence both the accuracy of the results and the computational time.
... Several studies have analysed and presented the benefits of thermal zoning e.g. [1] and there are international standards and guidelines available for regulating the implementation methodologies. ...
... Thermal zoning features and methods have generally been investigated in the BPS context to be able to accurately represent the real building performance (see for example Heidell et al. [13]) or to understand the effect of modifying the number of zones on the performance of a detailed multi-zone model [14], as inferred from a recent review by Shin and Haberl [1]. These studies typically compare: Monitored building energy consumption against simulated results with different zoning strategies. ...
Article
Full-text available
Thermal zoning is a commonly adopted building energy efficiency initiative, since thermally segregating conditioned spaces is generally expected to minimise energy losses when conditioning unoccupied spaces. When comparing a partitioned building with widely differing heat gains between zones to an equivalent non-partitioned building, ’zoning’ might not always beneficial. This paper analyses the fundamental thermal processes involved in these scenarios by firstly undertaking a number of steady state analyses, demonstrating that there are scenarios where the thermal energy required to maintain comfort conditions is less for an open-plan arrangement than for a more highly partitioned building. We then performed dynamical simulations of a simple building, confirming the steady state analyses and showing that, for space heating, connecting the spaces can significantly reduce the energy demand. It was concluded that whenever two zones are both conditioned to the same set-points, thermally connecting zones always leads to an energy demand lower or equal to thermally isolated zones. We then conducted simulations of an archetypal residential building with intermittent conditioning of spaces. The results showed that thermally connecting the spaces can be beneficial in climates from cool to warm temperate, with a decrease in energy demand from 2.2 to 9.9%, while this was not beneficial in a hot and humid climate, with an energy demand increase of 0.2 to 2.3% for the thermally connected scenario.
... In the conceptual design stage, the room division of a building has not been determined. The one-zone per floor zoning method requires less modeling and computational time than the widely used core and perimeter zoning method (ASHRAE, 2016;Dogan et al., 2016;Shin and Haberl, 2019). In some cases, zone multipliers can be used for buildings with many identical zones (U.S. ...
Article
It is generally acknowledged that the decisions made in the early design stage of a building critically affect its performance. To promote sustainability, building simulations are widely used in the early design stage to calculate the building performance and optimize the design. However, the high computational burden limits the application of building simulations in daily design work. This paper proposes a hybrid metamodel-based method to facilitate the rapid assessment of a building's energy demand in the early design stage. This method (1) decomposes a complex building mass into several zones as different metamodel variants and characterizes the total energy demand by summing up the energy demands of all the metamodels; (2) uses the received solar radiation values as metamodel input parameters to describe the surrounding shading and reflection effects; (3) employs GPU acceleration technology to accelerate the radiation calculation and reduce the simulation time; and (4) implements a machine learning (ML) algorithm screening framework to enhance the accuracy of the metamodels. Case studies were conducted to demonstrate the proposed method. The results showed that this method could predict the energy demands of buildings in high-density urban environments with acceptable accuracy in a short period of time, which would allow designers to obtain feedback on the building energy demand immediately in the early design stage and opens up more possibilities for achieving low-energy buildings.
... A more practical application would be to implement the PBM into a whole building (or floor of a building), such as the Al Bahr towers [52]. This could then include the concept of thermal zoning and the floor layout for HVAC design [55], kinetic photovoltaic envelopes [56,57], clusters of responsive buildings [58], and management (maintenance, safety, and costs) [59]. Although the PBM with MOO process efficiently generated optimal solutions, as mentioned in Section 5, it took three to four days to test each CABE model with the reference office due to the large number of shading objects. ...
Article
Full-text available
This research presents a multi-objective optimization (MOO) framework to support the climate-adaptive building envelope (CABE) design decisionmaking process using a parametric behavior map (PBM). Unlike static shading, CABE systems include dynamic operations that significantly affect their performance; thus, well-informed strategies for scheduling dynamic operations should be integrated to analyze CABE performance. In this study, two conflicting objectives were pursued: minimizing cooling load and maximizing daylighting performance during the summer season in a hot and humid climate (Houston, Texas). Variables in the CABE performance optimization process were defined as dynamic operation schedules having either parametric linear or non-linear relationships between the degree of openness of the CABE model and certain weather stimuli (i.e., solar radiation). Two CABE models were tested with the PBM by integrating a parametric non-linear function that efficiently conducted the optimization process in a large search space. The outcomes of this optimization study included Pareto-front solutions such as optimal CABE performance and their dynamic operation scenarios. These optimal operation scenarios were determined based on the CABE design options available and user's desired objectives; in some cases, static scenarios were found to be superior. Ultimately, combining PBM with a MOO framework will contribute to the field of performance-based CABE design by supporting architects and engineers and facilitating better decisions through well-informed dynamic operation scenarios.
... The topology/layout includes the structural/nonstructural component layout such as shear wall/cores [59], floor geometry [10,20,[59][60][61][62], aspect ratio [63], and so on. From architecture, the heating/cooling zone layouts are established. ...
Article
The Architecture, Engineering, and Construction community is highly focused on designing buildings that can improve energy efficiency while maintaining adequate structural behavior (termed herein as energy-structure performance). Sensitivity analysis is a fundamental tool to identify the influential factors under this multidisciplinary setting which can be used for model calibration, model reduction, and design optimization. To enhance the study of energy-structure performance, a novel framework of sensitivity analysis, including initial studies and global sensitivity analysis, was developed based on a general and automated platform of multi-physics simulation. This platform meets the requirements of object-orientation and provides compatibility with parametrical representation, including geometric/non-geometric parameters and detailed modeling. A systematic methodology of sensitivity analysis considering sensitivity auditing and a Scaled Morris Method is developed within the context of hybrid building energy-structure performance. The refined global screening sensitivity analysis (Scaled Morris Method) is proposed to deal with different types of data inputs and multiple-output sensitivity index comparison problems. A building case study was part of the research, which included two types of façades totaling 15 input factors. More than 2000 simulations were conducted producing the yearly/peak energy performance indicators over four climate zones along with static/dynamic structural performance indicators. The results from the initial studies and global sensitivity analysis provided varying/sensitivity effects of building topology/layout, structural/nonstructural components, and inherited features, which were compared quantitatively. For the curtain wall building, the absolute mean (sensitivity indices) input factors were up to 2.3 for energy indicators and 3.0 for structural indicators. The precast concrete panel wall building exhibited the absolute mean of input factors up to 2.8 for energy indicators and 2.4 for structural indicators. Overall, the results indicate this new framework, methodology, and sensitivity analysis can be used for commercial hybrid building energy-structure performance analysis.
... If simpler models helped reduce the computation time, they also increased the error (1-13%) in cooling consumption. Shin et al. [39] showed through a literature review that today no precise thermal zoning rules exist but only simple guidance principles and parameters to be taken into account. ...
Article
With the growing interest in urban scale simulation, urban building energy modelling tools (UBEM) are being developed. The purpose of these UBEM is to tackle multiple issues that can range from buildings retrofit potential to the sizing of thermal and/or electrical network or to the assessment of renewable energy sources potential. Unlike the modelling of a single building, collecting accurate building information data at district scale is nearly impossible and therefore the uncertainties increase. In this context, the selection of the most relevant and adequate models with regard to the available data and simulation objectives is challenging and often a trade-off between accuracy and parametrization feasibility has to be found. A novel approach is proposed to choose the right level of model complexity for thermal heating demand simulation in buildings at district or city scale, by assessing in particular the impact of different thermal zoning methods with the UBEM tool DIMOSIM. This method for assessing the parsimony in modelling is applied to a selection of models from the literature in order to find a compromise between the available data, the different modelling levels of detail, the expected output and the computation time, according to the district and buildings characteristics. By applying this approach, it has been found that a division per floor for building modelling is in most cases the most parsimonious choice for thermal heating demand simulation at district scale. Eventually, the coupling between thermal zoning models and solar shading models is analysed through the same methodology for assessing the modelling parsimony. The results show that the combination of simpler models (in particular a thermal zone per floor or mono-zone buildings for thermal zoning models, and a solar shading coefficient calculated per floor or facade for solar models) can be parsimonious enough to be used to determine the annual heating demand, speeding up strongly the simulation at the same time.
... There have been a variety of approaches to automatically generate zones such as one-zone-per-floor, perimeter depth zoning, cardinal direction zoning, core-and-perimeter-zoning [169][170][171][172]. Among these approaches, ASHRAE's core-and-perimeter-zones approach yields the most reliable results and used widely at the early stages [165,173,174]. However, this approach requires expensive modelling efforts and computational time. ...
Thesis
Full-text available
Buildings represent one-third of energy consumption that concerns the global community. During the early design stages, designers have an opportunity to improve the energy performance of buildings efficiently. However, they need information to assess the effect of their design decisions on the energy performance. The doctoral research developed methods to support energy-related design decisions at the early stages using machine learning (ML) and building information modelling (BIM) by providing relevant information. The flexible representation of design at the early stages is a prime challenge to assess energy performance and the effect of design decisions on it. This challenge is addressed using a probabilistic approach that requires simulating several hundred models. Dynamic energy simulation tools are computationally expensive, prompting the development of quick metamodels using ML approaches. Further, a BIM integrated approach is developed to reuse the existing information and reduce the modelling efforts. The building design progresses by developing information through several levels of development (LOD). While focussing on energy efficiency, it is apt to reduce uncertainty in energy predictions through these LODs. Thus, the research identified design information in the order of its potential to cause uncertainty in the energy predictions. It has been found that geometrical parameters cause the maximum uncertainty in the energy predictions, followed by technical specifications such as U-values and window parameters such as window-to-wall ratio. These results form the basis for design information required in a multi-LOD context. The research further developed metamodels using ML for quick energy predictions, primarily, focussing on evolving building geometry, making it difficult to develop an ML model for early stage energy predictions. It extended the component based ML (CBML) approach and proposed using a convolutional neural network (CNN) approach to develop ML models. An approach of collecting diverse samples is developed to train CBML components and improve their generalisation. A CNN approach is used to capture the building geometry information from an image instead of simple parameters such as relative compactness. The developed model has improved prediction accuracy as the proposed CNN model architecture allows learning the interactions between the building’s geometry and its energy performance. There exists a prediction gap between ML predictions and dynamic simulations. A small prediction gap is allowed if it does not affect the comparative assessment of designs under the uncertain conditions of early design stages. Through a test case, the research demonstrated that the developed ML models are suitable to perform a comparative assessment of designs quickly. The aptness of ML models to provide quick comparative assessment of designs allows developing a BIM integrated solution and glean relevant information for supporting design interventions. In the final phase, a cloud based service was developed: p-energyanalysis.de. It implements the developed ML models in a graphical user interface for practical applications. The tool provides information for design space exploration, energy analysis of options and their comparative assessment, sensitivity analysis, and tracks progress. Contrary to generic engineering knowledge, the developed tool extracts context-specific energy performance information. This information is more relevant as it captures the effect of changing design scenario on the energy-efficiency. The thesis facilitates the performance-oriented building design by providing relevant information using ML and BIM. The developed methods focus on informed design making from an energy perspective that can be extended to other performance evaluations. Besides developing ML models for energy prediction, this research integrates these models with BIM to extract useful information for supporting design interventions. The developed holistic approach provides a quick context-specific assessment of design interventions that enables the designer to make informed decisions.
... There have been a variety of approaches to automatically generate thermal zones such as one zone per floor, perimeter depth zoning, cardinal direction zoning, core and perimeter zoning [38][39][40][41]. Among these approaches, ASHRAE's core and perimeter zone divisions approach are expected to yield the most reliable results and used widely at the early stage [34,42,43]. However, this approach requires expensive modelling efforts and computational time. ...
Article
The energy-efficient building design requires building performance simulation (BPS) to compare multiple design options for their energy performance. However, at the early stage, BPS is often ignored, due to uncertainty, lack of details, and computational time. This article studies probabilistic and deterministic approaches to treat uncertainty; detailed and simplified zoning for creating zones; and dynamic simulation and machine learning for making energy predictions. A state-of-the-art approach, such as dynamic simulation, provide a reliable estimate of energy demand, but computationally expensive. Reducing computational time requires the use of an alternative approach, such as a machine learning (ML) model. However, an alternative approach will cause a prediction gap, and its effect on comparing options needs to be investigated. A plugin for Building information modelling (BIM) modelling tool has been developed to perform BPS using various approaches. These approaches have been tested for an office building with five design options. A method using the probabilistic approach to treat uncertainty, detailed zoning to create zones, and EnergyPlus to predict energy is treated as the reference method. The deterministic or ML approach has a small prediction gap, and the comparison results are similar to the reference method. The simplified model approach has a large prediction gap and only makes only 40% comparison results are similar to the reference method. These findings are useful to develop a BIM integrated tool to compare options at the early design stage and ascertain which approach should be adopted in a time-constraint situation.
... The results show that the HVAC system is always the most important research topic, especially the heating system. Meanwhile, the indoor thermal environment is the most important factor that will directly affect the HVAC system [70,71]. Therefore, these two research topics are closely connected in all phases. ...
Article
Full-text available
The rapid increase in the number of online resources and academic articles has created great challenges for researchers and practitioners to efficiently grasp the status quo of building energy-related research. Rather than relying on manual inspections, advanced data analytics (such as text mining) can be used to enhance the efficiency and effectiveness in literature reviews. This article proposes a text mining-based approach for the automatic identification of major research trends in the field of building energy management. In total, 5712 articles (from 1972 to 2019) are analyzed. The word2vec model is used to optimize the latent Dirichlet allocation (LDA) results, and social networks are adopted to visualize the inter-topic relationships. The results are presented using the Gephi visualization platform. Based on inter-topic relevance and topic evolutions, in-depth analysis has been conducted to reveal research trends and hot topics in the field of building energy management. The research results indicate that heating, ventilation, and air conditioning (HVAC) is one of the most essential topics. The thermal environment, indoor illumination, and residential building occupant behaviors are important factors affecting building energy consumption. In addition, building energy-saving renovations, green buildings, and intelligent buildings are research hotspots, and potential future directions. The method developed in this article serves as an effective alternative for researchers and practitioners to extract useful insights from massive text data. It provides a prototype for the automatic identification of research trends based on text mining techniques.
... The first strategy involves spatial thermal zoning; in other words, compartmentalization. Thermal zoning allows the temporal use of spaces depending on comfort needs. A building is divided into separate thermal zones where occupants can select the most comfortable zone and control the comfort conditions through passive or/and active systems [2]. Careful thermal zoning effectively reduces the heating or cooling energy demand in the occupied spaces [3]. ...
Article
Full-text available
Climate responsive design can amplify the positive environmental effects necessary for human habitation and constructively engage and reduce the energy use of existing buildings. This paper aims to assess the role of the thermal adaptation design strategy on thermal comfort perception, occupant behavior, and building energy use in twelve high-performance Belgian households. Thermal adaptation involves thermal zoning and behavioral adaptation to achieve thermal comfort and reduce energy use in homes. Based on quantitative and qualitative fieldwork and in-depth interviews conducted in Brussels, the paper provides insights on the impact of using mechanical systems in twelve newly renovated nearly-and net-zero energy households. The article calls for embracing thermal adaptation as a crucial design principle in future energy efficiency standards and codes. Results confirm the rebound effect in nearly zero energy buildings and the limitation of the current building energy efficiency standards. The paper offers a fresh perspective to the field of building energy efficiency that will appeal to researchers and architects, as well as policymakers.
... Some researches started to investigate the topic of the "green dimension" [5]. Indeed, to optimize the design in terms of energy efficiency, it could be useful that the energy simulation phase be carried out in meantime with the development of the project [6] and to make choices based on intermediate calculations, and therefore constantly modify the project until the objectives are achieved [7]. To do this, it is often necessary to build another digital model, called BEM (Building Energy Model), or implement the BIM model with all the information needed for energy simulation (occupation of the rooms, calculation of thermal bridges, analysis based on hourly climate data, etc.) [8]. ...
Article
Over the years, building information modelling (BIM) has undergone a significant increase , both in terms of functions and use. This tool can almost completely manage the entire process of design, construction, and management of a building internally. However, it is not able to fully integrate the functions and especially the information needed to conduct a complex energy analysis. Indeed, even if the energy analysis has been integrated into the BIM environment, it still fails to make the most of all the potential offered by building information modelling. The main goals of this study are the analysis of the interaction between BIM and energy simulation, through a review of the main existing commercial tools (available and user-friendly), and the identification and the application of a methodology in a BIM environment by using Graphisoft's BIM software Archicad and the plug-in for dynamic energy simulation EcoDesigner STAR. The application on a case study gave the possibility to explore the advantages and the limits of these commercial tools and, consequently, to provide some possible improvements. The results of the analysis, satisfactory from a quantitative and qualitative point of view, validated the methodology proposed in this study and highlighted some limitations of the tools used, in particular for the aspects concerning the personalization of heating systems.
... Based on previous studies (e.g. (Georgescu and Mezić, 2015) (Klimczak et al., 2018), (Shin and Haberl, 2019) ("DesignBuilder Help -Merging Zones," n.d.)), merging zones through same activity can reduce simulation time but does not have a notable impact on the results. In the most detailed model version, the internal thermal mass of the partition walls was modelled by applying hanging partition walls. ...
Conference Paper
Full-text available
Designers can select between different energy performance calculation models starting from simplified typology-based seasonal methods to detailed dynamic building simulation tools. Results are significantly influenced by the model simplifications. However, even the most complex and precise model can lead to false results if the necessary set of inputs are not properly determined. In real life conditions, it is often the case that input data are roughly estimated as exact specification is not possible due to time or budgetary limitations. One of the most disputable set of input parameters are related to occupants' behaviour and building operation. Current paper compares different calculation models and occupant profiles based on standardised and measured values. Results are compared to real time consumption data from smart meters. Typical false operation modes are investigated to quantify the wasted energy as a consequence. The gap between standardised and real occupant behaviour coming out of two case study examples can help decision makers and improve knowledge to better consider the human factor in building energy modelling.
... Then, the buildings are split into dwellings assuming a floor height of three meters. Each dwelling is modeled as a single thermal zone, which is acceptable due to the small temperature differences expected between the different rooms [29]. Indeed, the dwellings are characterized by a small volume, a single set point temperature and an inter-zonal ventilation flow rate. ...
Article
With the increasing share of intermittent renewable energy sources in the energy mix, demand-side flexibility is likely to play a key role in the future. For buildings, flexibility is defined as the ability to shift their energy consumption away from “peak periods” i.e. high-demand periods of the electrical network. In France, these episodes occur mainly during the wintertime due to the significant demand for space heating. To achieve flexibility objectives, we explore an indirect control strategy at district scale by adjusting the dwelling thermostat during peak periods. The study is conducted on 337 dwellings in order to better predict the load curve by taking advantage of the aggregation effect. Three main research questions are addressed in relation to the assessment of flexibility potential: (i) the effect of aggregation, (ii) the identification of the most influencing factors, including occupant behavior, and (iii) the quantification of uncertainties. Using an urban building energy modeling tool populated with various national data sources (building envelope, energy class of equipment, etc), we perform a sensitivity analysis on 22 parameters representing the geometry, the appliances, the building characteristics, the occupants, and the grid. The output indicator is the average power shifted during the flexibility (or demand response) event. From this analysis, 7 parameters appear as being the most influential. A regression analysis on these parameters is performed, depending on both the duration of the event and the typology of the district. The results show that the duration of the flexibility event and the occupant pre-selected temperature change are the most influential parameters. It results to approximately ±90 W of uncertainty on an average potential of 290 W of shiftable power per household in a recent district. Furthermore, the occupants are highlighted as making a significant contribution to flexibility. Finally, we observed that the thermal properties investigated with the study of an old fabric district play a key role. Low thermal performance means high heating consumption and increased flexibility potential, but a similar relative uncertainty.
... However, since this feasibility study focuses on the demonstration of the workflow, we used the traditional core-perimeter zoning method of EnergyPlus. Since the room is not as large as other reference commercial buildings and a core zone would not have any natural ventilation, only perimeter thermal zones were created with a zone depth of 4.55 [m], which is a reasonable size for perimeter zones [72]. ...
Article
The evaluation of natural ventilation potential for cooling indoor spaces during the early design phases is of great interest to researchers and practitioners. Among various definitions and usages for natural ventilation potential (NVP) in early design evaluation, this paper reviews and identifies the key performance indicators, and proposes two new dynamic metrics—natural ventilation cooling effectiveness (NVCE) and climate potential utilization ratio (CPUR). The metrics are dynamically responsive to various design options, in both steady and transient states, allowing consideration of thermal mass. Assisting in design development processes, the metrics quantify how well indoor spaces make use of natural ventilation's cooling capacity. Case studies are presented to demonstrate how NVCE and CPUR enable designers to evaluate the predicted performance and how to apply the information to improve building design. The results of the design iterations showed that the relationship among various design parameters should be dynamically understood in order to evaluate the performance of natural ventilation, confirming that “the more the airflow, the greater the potential,” and “the heavier the thermal mass, the greater the energy saving” were not always true.
... Energy consumption in buildings must be reduced at a high rate because they play an important role in polluting the environment [1][2][3][4][5][6]. Adding nanoparticles, using heat recovery [7][8][9][10][11][12], utilizing renewable energies, improving the performance of the cooling [13][14][15][16][17][18][19][20][21][22][23][24] and heating sections [25][26][27], hot water supply [28][29][30], adding internal shade [31][32][33] along with external shade [34][35][36], incorporation photovoltaic cells [37][38][39][40][41] and installing PCM [42][43][44][45] are effective methods resulting in less energy consumption. ...
Article
In this study, the effect of phase change material on walls and roof considering solar intensity was discussed. Due to the geographical location of the city of Jeddah in Saudi Arabia, the effect of installing phase change material within thicknesses of 1–10 cm in the period from April 1 to September 30 was investigated. Numerical results showed that if phase change material is added to the roof (at 1 cm), the heat transfer not only did not decline but also increased. However, for the walls in the main directions, phase change material (at 1 cm) was useful. Based on the results, the western wall was the most sensitive wall to phase change material presence so that the addition of phase change material at 1–5 cm resulted in energy-saving by 2.4–7.2 kWh/m². Although phase change material at a thickness of 1 was not useful for the roof, at thicknesses of 2–5 cm, the presence of phase change material reduced the energy exchange by 1.21–33.8 kWh/m². Finally, it was found the best results are obtained by adding phase change material for the western wall and roof. Examining the energy-saving for building by adding phase change material, it was found that adding phase change material with thickness up to 5 cm is recommended. Further increase in thickness reduces the positive effects of phase change material.
... Shin et al. [8] state that Building Energy Performance Simulation (BEPS) programs are widely used as a support for building design and systems. Crawly et al. [9] provide a comprehensive review of the most relevant BEPS programs, in which EnergyPlus [10], DOE2 [11] and TRNSYS [12] could be highlighted for their recognized standing. ...
Article
Full-text available
The calculation of sunlit surfaces in a building has always been a relevant aspect in building energy simulation programs. Due to the high computational cost, some programs use algorithms for shading calculation for certain solar positions after discretization of hemispherical sky. The influence of the level of discretization on the estimation of incident direct radiation on building surfaces, as well as on the required computational times, are studied in this work. The direct solar energy on a window for a year, with simulation time steps of five minutes, has been simulated by using an algorithm based on Projection and Clipping Methods. A total of 6144 simulations have been carried out, varying window sizes, window orientations, typologies of shading devices, latitudes and discretization levels of the hemispherical sky. In terms of annual incident solar energy, the results show that maximum error values are about 5% for a low level of angular discretization. Errors up to 22% in hourly incident solar energy have been estimated for some of the configurations analysed. Furthermore, a great number of configurations show errors of shading factor on a window of up to 30%, which could be most relevant in studies of natural lighting. The study also shows that the improvement achieved by the most accurate discretization level implies an increase in computational cost of about 30 times.
... Comparing the cost-effectiveness of energy-conservation measures (ECMs) both at the design and operating stages using building data such as data from meters, sensors, heating costs, weather, energy usage and demand, temperature, humidity, and building characteristics, etc. [67][68][69]. The future of the building construction process depends on the automated exchange of data between the architect's design tools and the energy consultant's building energy simulation application [70]. Building energy simulation (BES) models are divided into two types: prognostic Law-Driven (or white box) and Data-Driven (or black box) models (or black box). ...
Article
Full-text available
This paper presents the common insulation material utilization during the operation process, besides the physical properties of materials. On the other hand, was compared the cost-effectiveness and the safety conditions of the material. Finally, this paper reviews the various software modelling and simulation tools to choose the easy interface comprehensive for design, analysis, and calculation of the energy required to preserve building performance criteria based on the inputs of building properties as well as the mechanical and dynamic systems.
... Energy efficiency is one of the important issues of today's world, wherein the importance of energy resources is increasing day by day. Furthermore, to minimize energy consumption, new energy policies, which consist of different efficiency criteria of systems regulations, should be brought along [1]. It is to be noted that the rapid depletion of limited energy resources necessitates the dissemination of renewable energy resources. ...
Conference Paper
Full-text available
Recent developments in hardware and software enable us to develop resource-aware and computationally efficient optimal control strategies, which are important for efficiently usage of energy resources. Event-based control is one of the energy-efficient methods especially for distributed and complex control systems. The prominent feature of the event-based control is the idea of removing unnecessary updating of control input when the system state stays in desired bounds. This paper focuses on the central idea of event-triggered and time-triggered control strategies for Heating, Ventilating, and Air Conditioning (HVAC) applications. Furthermore, recent techniques on HVAC are classified concerning some prominent features. Thus, the present research provides an in-depth guide for designers who investigate the HVAC control application.
... EN ISO 52016-1 provides general guidelines for zoning buildings, suggesting that all adjacent spaces in the same category should be grouped together in a single thermal zone. Despite these indications many studies collected by Shin et al. [17] show that it is appropriate to divide the space into different thermal zones according to solar loads, orientation, occupancy and air conditioning schedule. Therefore, each room of the building was defined as a different thermal zone. ...
Article
Full-text available
The EN ISO 52016-1: 2017 standard introduced a new methodology for the hourly calculation of energy needs that allows the study of the dynamic energy performance of buildings. In this study, a comparative analysis was carried out between two heat transfer models for opaque building elements: the one described in the new standard EN ISO 52016-1: 2017 (Annex B) and that proposed by the Italian national annex (Annex A). The analysis, carried out on 1854 cases, showed better results for the heating period than for the cooling period, with a lower Root-Mean-Square Error and Coefficient of Variation of the Root-Mean-Square Error for the model proposed by the Italian National Annex. Increasing the performance of the building by decreasing the solar transmission coefficient of the glazed surfaces leads to a worse Root-Mean-Square Error of about 11%. In addition, a sensitivity analysis of the thermo-physical parameters of the opaque building components was carried out and an alternative method for the calculation of the solar transmission coefficient was evaluated. The latter was able to improve the Root-Mean-Square Error of summer solar gains by 46.7% compared to the method proposed by the standard.
Article
Residential buildings account for 20% of total energy consumption in the United States, with single family detached houses accounting for 77% of residential site energy consumption. A multizone variable air volume (VAV) system can save energy by directing conditioned air to different occupied zones in the home as needed. While multizone VAV systems in single family houses have been economically inaccessible in the past, recent technological developments in building automation controls and the Internet of Things (IoT) can enable homeowners to retrofit their existing HVAC systems into VAV systems, warranting further investigation into the energy savings potential of such systems. Past residential VAV system research mostly involved simulations and measurements of singular case study houses over short periods of time. In this study, representative energy models of two different house sizes, with estimates of individual room sizes, were developed to expand on those case studies and examine energy savings for single family homes across seven US climate zones over an entire year. Average size house models report 24%–42% source energy savings while large house size models report 18%–35% source energy savings, with houses in cooling dominant climate saving relatively more. Annual energy cost savings range from 24% to 42% for average size house models and 18%–35% for large size house models. These results indicate greater energy savings potential for single family homeowners considering VAV retrofits in cooling climates and areas with higher cost of electricity. Projected present value of energy cost savings over a typical home ownership period similarly yielded favorability for houses in cooling dominant climates, but were impacted by energy price changes over time. Future research should focus on the payback analyses of single family VAV system implementations and its sensitivity to occupant behavior. The details of the representative energy models, with estimates of room sizes and occupancy schedules, are provided for future studies that focus on multizone energy saving strategies.
Article
TO (transformation optics)-based transformation thermotics offers an advanced way to design the propagation path of heat flux at will, which is valuable for the regulation and utilization of thermal energy. Thermal concentrator as one of the typical representatives has great application potential in fuel cells, solar thermal collectors, heat storages, and other energy related devices due to its advantageous functionality and efficiency. However, most existing TO-based thermal concentrators only perform the same thermal rectification effect in different environments, which is limited in industrial applications and insufficient to meet diverse requirements. In this work, based on the improved temperature-dependent transformation thermotics theory and taking thermal protection issue into account, we designed an intelligent thermal concentrator, which can spontaneously exhibit different working states corresponding to different environmental conditions; investigation and optimization of structural sensitivity were also carried out toward two impact factors. In addition, the proposed model was theoretically realized referring to wedge-like shaped materials, and two thermal control apparatus were enumerated as extensions of current work. The proposed intelligent thermal concentrator possessing nonlinear characteristic as well as active functionality can provide reference for energy collection equipment in industrial application, and the revealed methodology can be expanded to design other types of TO-based devices in thermal even multi-physical field.
Article
Full-text available
In this study we analysed the climatic conditions for infiltration estimation, different calculation methods and infiltration impact on heat load for heating systems dimensioning. To determine the wind conditions at low air temperatures of the coastal- and inland climatic zones in Estonia, 42 years of climatic data for Tallinn and Tartu were investigated. Calculation models with detailed air leakages were constructed of a single and two-storey detached house using dynamic simulation software IDA ICE. Simulations were carried out with the constructed calculation models, simulating various wind and sheltering conditions to determine the heating load of the buildings under measured wind conditions at the design external air temperatures. The simulation results were compared with results calculated with European Standard EN 12831:2017, methodology given in the Estonian regulation for calculating energy performance of buildings and with simulations using the default settings in IDA ICE based on the ASHRAE design day conditions. The percentage of heat losses caused by infiltration was found as 13-16% of all heat losses for the studied buildings. Simulations with historical climate periods showed that even in windy weather conditions the heating system dimensioned by the methods analysed may not be able to provide the required indoor air temperature. Analysis using the coldest and windiest periods showed that when systems are dimensioned by the studied methods, the highest decline in indoor air temperature occurs on the windiest day and not on the coldest day. The impact of high wind speeds and low sheltering conditions resulted up to 50% of all heat losses.
Article
Full-text available
The COVID-19 pandemic, through governmental stay-at-home orders, forced rapid changes to social human behavior and interrelations, targeting the work environments to protect workers and users. Rapidly, global organizations, US associations, and professionals stepped in to mitigate the virus's spread in buildings' living and work environments. The institutions proposed new air system HVAC settings without efficiency concerns, such as improved flow rates and filtering for irradiation, humidity, and temperature. Current literature consensually predicted an increase in energy consumption due to new measures to control the SARS-CoV-2 spread. The research team assumed the effort of validating the prior published outcomes, applied to US standardized high-rise office buildings, as defined and set by the key entities in the field, by resorting to a methodology based on software energy analysis. The study compares a standard high-rise office building energy consumption, and CO2 emissions and operations costs in nine US climate zones — from 0 to 8, south to north latitudes, respectively —, assessed in specifically the most populated cities, between the previous and post COVID-19 scenarios. The outcomes clarify the gathered knowledge, explaining that climate zones above mixed-humid type (4) tend to increase relative energy use intensity by 21.72%, but below that threshold the zones decrease relative energy use intensity by 11.92%.
Article
Building cooling and heating accounts for a large portion of total global energy use and requires commensurate amounts of resources, which contribute significantly to global warming. Traditionally, addressing this issue has meant improving the efficiency of equipment supplying the thermal energy, reducing envelope heat transfer, and reducing air infiltration. However, this approach is already reaching practical limits. In this perspective, we explore (1) how to reduce thermal load in buildings theoretically and (2) how to achieve that reduction and dramatically lower the energy required to support building loads practically. First, we discuss our framework developed for calculating the theoretical minimum thermal load (TMTL) in buildings. Our analysis shows that current thermal loads in buildings are more than an order of magnitude higher than the TMTL. We also introduce an approximate formula to calculate energy savings from zonal control of thermal load, which shows that the majority of zonal control benefits can be achieved with fewer than 10 zones. Then, we discuss pros and cons of various approaches and strategies to achieve the TMTL. We conclude our perspective with some longer-term R&D ideas, such as thermally adaptive clothing and thermal storage to help approach the TMTL, while providing the additional benefit of interacting with the renewable grid of the future.
Article
The coupled pipe-encapsulated PCM wall system with a nocturnal sky radiator is a novel type of building envelope structure for low energy buildings. It absorbs outdoor heat and stored it by using the pipe-encapsulated PCM inside the wall in the daytime, and the stored heat is automatically discharged into space through the sky radiator by the effect of the gravity heat pipe at nighttime. It makes full use of the natural cooling source, which can effectively reduce indoor heat gain through the envelope and improve the utilization efficiency of PCM. In this paper, an experiment platform integrating the pipe-encapsulated PCM wall module, the nocturnal radiator module, the heat pipe circulation module and measurement system together is established. The heat transfer characteristics of the wall system in four cases under the dynamic boundaries are tested, and the performances are contrastively discussed. Comparing to the wall without nocturnal radiation, the coupled wall system can well reduce the indoor cooling load and the wall internal surface temperature. The wall internal surface average heat flux can reduce 10.2 W/m², and the cumulative indoor heat gains can reduce 29.7%. The results show the good thermal performance and energy-saving potential of this coupled pipe-encapsulated PCM wall system with a nocturnal sky radiator. With the development of new materials for enhancing the capability of radiative cooling such as the glass-polymer hybrid metamaterial, the performance of the coupled wall system may be significantly improved when these materials are used in the sky radiators.
Article
Historically, humanity has considered the control of cooling and heating an aspect related to both comfort and survival, currently being it evaluated not as a luxury, but as a fact of modern existence. In the global context, at the beginning of the 20th century, the efforts to develop cooling techniques with the aim of maintaining control climate at indoor spaces of the office and residential buildings, were evident. This initial direction that is taken to achieve comfort levels in terms of cooling and heating generates what is now called heating, ventilation, and air–conditioning (HVAC). This paper provides a general description of the zoning methods that support the structural description of the thermal zones of a building, required for the design, control and maintenance of HVAC systems. The main objective of this study is to systematically review the current research on zoning HVAC residential systems. The article conclusion is that an intelligent zoning strategy using a criterion associated with user behavior, occupancy patterns and its corresponding schedules, will promote the development of efficient optimization processes for energy consumption and thermal comfort if they are considered as a structural part of the HVAC system. Finally, in terms of modeling the advice is to start with a white box model, phenomenological, but to follow-up or support it with data-based models.
Article
In the last years, building energy consumption minimization has come to be an important issue for designers also architects. Different building energy simulation (BES) tools were applied. These programs are efficient to estimate building energy demands and quicken the malfunction assessment. Many of the provided energy simulation tools cannot precisely forecast building energy operation because of numerous interacting variables. To lessen considerable discrepancies between the actual-time data measurements and the simulation achievements, an optimization-based calibration method is presented in this study. Therefore, to minimize this error an optimization algorithm called Slime Mold Optimization (SMO) algorithm is utilized also the energy simulation model. A case study, an office building placed in Dubai, the United Arab Emirates (UAE) in a humid and hot climate region is selected to be modeled and adjusted to show the accuracy of the applied procedure. This case has five floors with 3610 m2 footprint. The building uses only electrical power as the major energy source For the total dataset duration (n = 3216), the MBE of an hour for the calibrated model is equal to 3.24 percent with the CV (RMSE) equal to 11.3 percent. The statistical evaluation has been used for analyzing the precision of the achievements. Based on the results, the procedure is reliable.
Article
Purpose Heating, ventilation and air-conditioning (HVAC) systems account for approximately half of all energy usage in the operational phase of a building's lifecycle. The disproportionate amount of energy usage in HVAC systems against other utilities within buildings has proved a huge cause for alarm, as this practice contributes significantly to global warming and climate change. This paper reviews the status and current trends of energy consumption associated with HVAC systems with the aim of interrogating energy efficiency practices for improving HVAC systems' consumption in buildings in the context of developing countries. Design/methodology/approach The study relied predominantly on secondary data by analysing the relevant body of literature and proposing conceptual insights regarding best practices for improving the energy efficiency of HVAC systems in buildings. The systematic review of the literature (SLR) was aided by the PRISMA guiding principle. Content analysis technique was adopted to examine germane scholarly articles and finally grouped them into themes. Findings Based on the SLR, measures for enhancing the energy efficiency of HVAC systems in buildings were classified based on economic considerations ranging from low-cost measures such as the cost of tuning the system, installing zonal control systems, adopting building integrated greenery systems and passive solar designs to major approaches such as HVAC smart technologies for energy management which have multi-year pay-back periods. Further, it was established that practices to improve energy efficiency in buildings range from integrated greening system into buildings to HVAC system which are human-centred and controlled to meet human modalities. Practical implications There is a need to incorporate these energy efficiency practices into building regulations or codes so that built environment professionals would have a framework within which to design their buildings to be energy efficient. This energy efficient solution may serve as a prerequisite for newly constructed buildings. Originality/value To this end, the authors develop an integrated optimization conceptual framework mimicking energy efficiency options that may complement HVAC systems operations in buildings.
Article
Artificial intelligence shows powerful capacity in modern building fault detection and diagnosis (FDD) systems. Existing data-driven-based FDD models are typically developed based on experimental data or simulation data and their performance highly depend on the data quality. Nevertheless, the available data in real buildings are often uncertain due to innate measurement errors, discontinuous sampling, sensor aging, etc. Accordingly, existing data-driven-based approaches may not present sufficient values for practical applications. This paper investigates the impacts of data uncertainty on data-driven-based building FDD model from two levels. At the high level, the impacts of data uncertainty on performance of FDD model are examined under different input feature numbers, i.e., 3, 8, 22 and 36. At the low level, the impacts of data uncertainty under various input features are evaluated at four uncertainty levels. The Coefficient of Performance Degradation (CPD) index is designed to quantify the impacts of data uncertainty. The chiller operation data of the ASHRAE 1043-RP project is employed as a case study. Diagnosis results reveal that the performance of FDD model will decline as the reduction of feature number under uncertain inputs. Besides, the diagnostic accuracy dramatically descends with increases of uncertainty level. The maximum accuracy decline is 20.9% when uncertainty level of kW increased from ±0.0 to ±1.0. Moreover, results show the data uncertainties cause greater effects on diagnosing global fault rather than diagnosing local fault.
Article
In view of advancing global warming, climate change adaptation and mitigation measures for buildings are becoming increasingly important. The following article discusses the question of whether current urban planning principles still provide a suitable framework for this purpose. Therefore, the aim of this paper is to identify and quantify the main parameters of the urban planning framework regarding energy demand and energy generation of buildings. In a novel, holistic approach, passive design measures were evaluated in a joint analysis based on a case study in the city of Vienna (Austria) with respect to their impact on heating and cooling energy demand, overheating potential, daylight availability, and solar potential of new buildings. The results show that by improving the thermal insulation of the building envelope, the importance of a high compactness of the buildings to lower the heating energy demand is decreased. In addition, moderate compactness can help reduce the energy demand for space cooling and artificial lighting and increase the solar potential of the buildings. Accordingly, the results question the dogma of a high degree of compactness that still exists to some extent and indicate that changing climatic conditions also require new approaches in the urban planning process.
Thesis
La recherche doit répondre aux enjeux énergétiques globaux afin de réduire les consommations énergétiques et les émissions de gaz à effet de serre pour limiter l’impact du changement climatique. Cette recherche s’appuie notamment sur le développement de nouveaux outils de simulation urbaine, appelés UBEM (Urban Building Energy Modelling), afin d’aider les collectivités, les bureaux d’études et autres acteurs de la transition énergétique à réduire les consommations d’énergie du secteur du bâtiment. Ces UBEM sont composés de modèles devant intégrer les problématiques de manque de données de paramétrage et de coût de calcul liés à la simulation urbaine. De nombreux modèles existent avec des niveaux de détail différents, afin de simuler l’ensemble des phénomènes physiques liés au bâti, aux systèmes énergétiques ou encore aux sollicitations extérieures, en respectant ces contraintes. De par cette grande diversité de modèles à disposition de l’utilisateur, ce dernier peut se retrouver dans des situations où la sélection des modèles les plus adaptés à son étude peut s’avérer fastidieuse et complexe. Ainsi, une méthodologie permettant de réaliser une simulation dite « parcimonieuse » est proposée dans cette thèse. La parcimonie de simulation a pour objectif de trouver le bon niveau de modélisation en déterminant le point d’équilibre entre : le nombre de paramètres d’entrée et leurs incertitudes, le niveau de détail du modèle avec ses hypothèses simplificatrices, la précision obtenue vis-à-vis d’une référence et le temps de simulation, le tout pour une sortie et un contexte donnés. Pour cela, des KGI (Key Guidance Indicators), créés à partir des caractéristiques liées à l’échelle quartier, sont utilisés afin de déterminer des valeurs seuils permettant de choisir quel niveau de modélisation utiliser suivant le quartier. Cette contribution permet de pouvoir conseiller et guider divers utilisateurs et modélisateurs, dans leurs modélisations urbaines, afin de proposer une simulation non pas la plus précise, mais la plus adaptée au cas d’étude. Cette thèse propose ainsi une méthodologie pour le développement d’outils d’aide à la décision plus parcimonieux et donc plus efficaces, permettant passer de la logique du toujours plus à juste ce qu’il faut.
Article
Although many previous studies have addressed the accuracy of building energy simulations, very few studies of this subject have mentioned the importance of Heating, Ventilation, and Air-Conditioning (HVAC) thermal zoning strategies to sustainable building design. In addition, the building energy standards and guidelines related to building energy simulation recommend that only a core and perimeter thermal zoning strategy be used to reduce the total number of thermal zones in a model. However, although this simplifies modeling, it can lead to too many thermal zones in the building energy model of a multi-story building, or in some cases too few zones, which can impact the model's accuracy. Therefore, the aim of this study is to develop a new thermal zoning process for building energy simulation called the “grid/cluster method.” that can be applied automatically to whole-building energy simulations of multi-zone commercial structures. To verify this new thermal zoning method, the indoor temperature profiles of grid units were carefully analyzed in a case study simulation. In this study, three thermal zoning simulation models for a rectangular building were created and applied in heating- and cooling-dominant climates. The results show that for both climate conditions, the new grid/cluster method reduced heating/cooling loads by 11%–27% as compared to the single-zone model. In addition, the results significantly improved the simulated indoor comfort conditions.
Article
Modeling multiple views of spaces involves mapping or transformation between multiple models. Automated model transformation is challenging as semantic and spatial criteria need to be considered. This paper proposes a novel method and data processing pipeline to define space views and semi-automatically transform room-based building data created in BIM authoring systems into multi-view space models. The method is based on space ontologies and their integration with space layout transformation operations. It is used to define a set of functional views that are relevant to schematic building design. An existing space modeling system is extended with the method and data processing pipeline. Results from a validation study show that the method can cover specific semantic and spatial aspects of space views. Both are relevant for consistent model transformation and accurate analysis. Results further show that it is feasible to fully automate data processing steps, except for space classification, which is semi-automated.
Article
Simplification of building energy models is one of the most common approaches for efficiently estimating the energy performance of buildings over a whole city. In city-scale models, the abstraction of a building into an information model and the division of the model into representative thermal zones cannot be building-specific but must be generic and applicable to many buildings. Considering the limited research on the performance of such methods, in this study, a comprehensive evaluation of the most relevant assumptions on zoning configurations and levels of detail is conducted in three building energy simulation tools IDA ICE, TRNSYS, and EnergyPlus. The findings from the evaluation of zoning configuration on building level and its comparison with the measured energy performance of buildings suggest that a single-zone model of a residential building gives a very similar result to a multi-zone model with one core zone and perimeter zones for every floor of the building. For the single-zone model, IDA ICE overestimates and EnergyPlus underestimates the energy demand compared to the more complex models by approximately the same amount, but EnergyPlus is preferred due to the shorter simulation time. It is also proven that higher levels of detail in building models can increase the accuracy of the results by approximately 6% annually. When extending the scope of the study from building level to district level analysis where a somewhat lesser degree of accuracy can be allowed on the individual building, the simplified models give acceptable results.
Article
Dynamic Insulation Materials (DIMs) present an opportunity to reduce the energy consumption of buildings by allowing heat transfer through the envelope at times when it is beneficial. Studies in the past have investigated a binary R-value control in which the thermal resistance of the wall is either “on” or “off. This study attempts to improve on this control strategy by maximizing the amount of beneficial heat transfer through the envelope using wall surface temperatures, the heating/cooling set-point temperature, and the temperature in the middle of the wall as parameters. It is found that adding a period during which the R-value of the wall can vary continuously within a defined range has the potential to modestly decrease the heating and cooling energy consumption. However, it is found that the most energy savings can be achieved by using a 2-step operation with settings slightly modified from previous studies. For a parametric analysis specific to a residential building in Golden, Colorado, the optimized operation mode produced heating energy savings of 9.3% and cooling energy savings of 21.0% relative to static RSI-3.8 insulation. Moreover, a parametric analysis was conducted to extrapolate the findings to multiple US cities with different climate zones. It is found that the optimized operation mode offers some energy savings for residential buildings in all US climates, though the extent of the savings and the optimized parameters are dependent on climate. Specifically, climates with low cooling degree-days have the potential for a higher reduction of cooling energy up to 35%, while climates with low heating degree-days are found to have the potential for a significant decrease in heating energy of over 80% relative to static insulation.
Article
Full-text available
A framework for creating thermal zones in a building for effective and efficient Heating Ventilation and Air conditioning (HVAC) system design is introduced here. This method is based on simple “sort and eliminate” schemes and requires design cooling loads of conditioned spaces obtained from load calculation tools as primary input. The developed methodology is applied for creating thermal zones, determining corresponding supply conditions and ascertaining sizing of a dedicated outdoor air system (DOAS) with local recirculating units. A simulation study on a prototype-building model shows that a DOAS coupled with zoned recirculating systems that serve distinct thermal zones in a building (zoned model) perform comparatively better in controlling both space temperatures and humidity without significantly compromising HVAC energy and chiller loads than un-zoned HVAC systems serving the whole building as a single thermal block (un-zoned model). The consistency in the performance of zoned HVAC systems is verified by applying three different simulation weather files for New Delhi. Better performance along with logical and computational simplicity makes this design procedure a good alternative to traditional methodologies.
Article
Full-text available
In this paper the authors present an algorithm that abstracts an arbitrarily shaped set of building volumes into a group of simplified ‘shoebox’ building energy models. It is shown that for generic perimeter and core floorplans the algorithm provides a faster but comparably accurate simulation results of annual load profiles vis-à-vis multi-zone thermal models generated according to ASHRAE90.1 Appendix G guidelines. Envisioned applications range from rapid thermal model generation for urban building energy modelling to schematic architectural design. Following a description of the algorithm, its ability to produce load profiles for a mixed-use neighborhood of 121 fully conditioned buildings for a variety of climates is demonstrated. The comparison yields relative mean square errors in simulated annual building energy use intensity of five to 10 percent compared to ASHRAE 90.1 compliant building energy models while reducing simulation times by a factor of 296.
Conference Paper
Full-text available
In this paper we present an algorithm for automated multi-zone building energy model production for urban and schematic design. By reviewing current guidelines for thermal zone discretization of early design building energy models [BEM] we present an argument that current zoning guidelines effectively recommend the use of a straight-skeleton like subdivision. Based on this finding, our procedure accepts an arbitrary building massing and subdivides each floor into core and perimeter thermal zones. As a proof of concept the algorithm was implemented as a plug-in for the parametric design environment Grasshopper for Rhinoceros. A number of examples of various complexities are shown to demonstrate its robustness and suitability for automated multi-zone BEM generation.
Conference Paper
Full-text available
Building energy simulation is valuable during the early stages of design, when decisions can have the greatest impact on energy performance. However, preparing digital design models for building energy simulation typically requires tedious manual alteration. This paper describes a series of five automated steps to translate geometric data from an unzoned CAD model into a multi-zone building energy model. First. CAD input is interpreted as geometric surfaces with materials. Second, surface pairs defining walls of various thicknesses are identified. Third, normal directions of unpaired surfaces are determined. Fourth, space boundaries are defined. Fifth, optionally, settings from previous simulations are applied, and spaces are aggregated into a smaller number of thermal zones. Building energy models created quickly using this method can offer guidance throughout the design process.
Article
Full-text available
As the scope of building design and construction increases and building systems become more integrated, the use of building energy models has become increasingly widespread in evaluating and predicting building performance. Despite the growing sophistication of building modeling tools, errors can arise from approximations that are made by a practitioner during model creation. This paper examines the process of model zoning, i.e., how the volume of a building is divided into regions where properties are assumed to be uniform. Zoning is performed during model creation to decrease model complexity. However, accuracy reduces when dissimilar regions of a building are defined by a single zone. In this paper, a systematic approach to creating zoning approximations is introduced. Utilizing the Koopman operator, the time-series output produced by a building simulation can be decomposed into spatial modes which capture the thermal behavior of a building at different time-scales. Identification of spatial structures within these modes forms a framework for the creation of simplified models of varying levels of granularity. In this paper, a detailed model is analyzed, and model accuracy is studied as coarser building representations are created using the introduced method.
Article
Full-text available
Although environmental performance-based methodologies are increasingly considered in the early design stages due to their potential for improving the final building performance, few studies have scrutinized the interoperation of floor-plan design and thermal zoning for the purpose of optimized building energy use and indoor comfort. The absence of effective tools, which aid designers incorporate an environmentally adapted thermal zoning into the space arrangement process, invokes the strong necessity for a new space layout design methodology based on optimal thermal zoning. Thus, this paper presents a highly practical decision support tool named EASL (Environmental Architecture Space Layout) optimizer to bridge the gap between thermal and spatial zoning within architectural workflows. In this software, performance evaluation using the whole building simulation tool (Ecotect) and zone-based layout creation techniques is integrated for the automated generation of an optimal geometry of space and envelope glazing, employing a simulated annealing algorithm. As a beta version, EASL uses typical office building space programmes and adopts four major performance criteria for evaluation such as annual energy use intensity, Predicted Mean Vote, daylight level, and room shading. Utilizing the tool provides two major strengths: (1) by introducing performance indicators to floor planning with an easy-to-use computerized interface during early design stages, architects can maximize the potential use of other sustainable strategies and technologies for later design decisions and (2) a time-efficient thermal zoning optimization process is achieved by exploring various scenarios that users are interested in testing. To this end, a case study was conducted of an office building located in South Korea using the developed simulation tool. The existing plan was tested to be rearranged and compared with the optimal layout obtained from EASL. The experimental findings demonstrate that this software can be implemented in practical operations, advancing early processes of design work, and be extended to embrace broader future applications to promote innovative environmental buildings.
Article
Full-text available
In this paper, we present a general algorithm to automatically convert arbitrary building massing models into multi-zone building energy models (BEM). The algorithm follows current guidelines for thermal zone discretization of BEMs when actual interior space boundaries are yet undefined. Envisioned applications are for rapid model generation during schematic building design as well as for urban massing studies. We present an argument that current recommendations for separating core from perimeter zones effectively follow a straight-skeleton subdivision. Following a step-by-step explanation of the procedure, a number of example building shapes of varying complexity are shown to demonstrate the algorithm's robustness and suitability for automated multi-zone BEM generation. Going forward, it is recommended that the algorithm is adopted by software developers to ensure more consistent thermal model production within the building simulation community.
Article
Full-text available
As the scope of building construction increases and de-signs become more integrated, building energy models have found widespread use in evaluating building per-formance. Despite the growing sophistication of build-ing modelling tools, errors can arise from the approxima-tions that are made during model creation. This paper ad-dresses model zoning, i.e., how the volume of a building is divided into regions where properties are assumed to be uniform. Zoning is important during the creation of a model because the accuracy of prediction from simu-lating a model reduces when dissimilar zones are lumped together. In this paper, a systematic approach to creat-ing zoning approximations is introduced to investigate the effect of zoning on simulation accuracy. Applying the Koopman operator, an infinite-dimensional, linear oper-ator that captures nonlinear, finite-dimensional dynamics without linearization, a detailed building model is stud-ied. Using the Koopman operator, the temperature history of rooms produced by a building simulation can be de-composed into Koopman modes. These modes identify dynamically significant behavior which will form a basis for the creation of zoning approximations. An implemen-tation of this technique is illustrated in a building model of an actual building designed with both mechanical and natural conditioning.
Article
Full-text available
The implications of the Probe post-occupancy survey project are discussed (methods and findings have been discussed in papers 1 to 4). Recent pressures to improve the UK building industry and its products have so far focused on production and not performance in use. Feedback, however, reveals successes which are not immediately apparent even to experts (when newly completed, the best all-round performer in Probe did not make the shortlist for an environmental award), and that innovations can easily have unintended consequences. Meanwhile, persistent chronic low-level problems need to be tackled if we are to move towards the triple bottom line of more sustainable practice and create a base of sound practice upon which innovations can flourish. Factors for success include making sure essential features are in place; seeking simplicity, usability, manageability and responsiveness; identifying and managing downside risks; a culture of feedback with better benchmarking and constant review against client and design intentions; and more involvement of the supply side in improving and learning from the performance of buildings in use. Seven main themes are explored and initial actions suggested for the key industry players, clients and government.
Article
Full-text available
Few field studies of energy performance of radiant cooling systems have been undertaken. A recently constructed 17,500m2 building with a multi-floor radiant slab cooling system in the tower was investigated through simulation calibrated with measured building energy use and meteorological data. For the very cold, dry region where the building was located, it was found that a typical floor of the tower would have had 30% lower annual energy use with a conventional variable air volume system than with the as-built radiant cooling-variable air volume combination. This was due to (1) simultaneous heating and cooling by the existing radiant cooling and air systems, (2) the large amount of free cooling possible in this climate, and (3) suboptimal control settings. If these issues were remedied and combined with improved envelope and a dedicated outdoor air system with exhaust air heat recovery, a typical floor could achieve annual energy use 80% lower than a typical floor of the existing building HVAC system. This shows that radiant thermal control can make a significant contribution to energy-efficiency, but only if the building design and operating practices complement the strengths of the radiant system.
Article
Full-text available
Energy simulation tools are increasingly used for analysis of energy performance of buildings and the thermal comfort of their occupants. This paper describes a selection of energy simulation engines and user interfaces that are capable of these analyses today. Specifically, it discusses the usage of these tools over different life-cycle stages. Besides a brief overview about energy simulation concepts, the paper illustrates each tool’s strengths and weaknesses as well as its data exchange capabilities. Given the significant variety of such energy simulation tools, it is crucial to understand limitations of the tools and the complexity of such simulations. The reliability of data exchange and straightforward, user-friendly interfaces are major aspects of the practical usage of these tools. Due to the huge amount of input data and the availability of rich 3D geometry models effective data exchange and software interfaces are crucial to enable faster and more reliable energy performance simulation analysis.
Article
Full-text available
This work investigated the degrees to which energy use in laboratory buildings may be influenced by interior space planning and/or the ways space is used. The potential influences of typical open, mixed and closed plan layouts and their space utilisation densities/intensities were investigated on a good-practice base case using the TAS, Lightscape and Excel software packages. The peak winter results indicated variations (potential savings) generally within a range of 40% (i.e., +20% of the respective base cases loads) except for the effect of open vs closed plans, which resulted in a variation of 73%. The summer load variations are within 50% across the open, mixed and closed layouts, and 84% across different closed plan layouts. These results indicate that the different ways in which users, activities and systems are organised against space-to-space environmental diversity are significant determinants of the energy performance of laboratories and perhaps other building types.
Article
Full-text available
Many assumptions must be made about thermal zoning and interzonal airflow for modelling the performance of buildings. This is particularly important for solar homes, which are subjected to high levels of periodic solar heat gains in certain zones. The way in which these passive solar heat gains are distributed to other zones of a building has a significant effect on predicted energy performance, thermal comfort and optimal design selection. This article presents a comprehensive sensitivity analysis that quantifies the effect of thermal zoning and interzonal airflow on building performance, optimal south-facing glazing area, and thermal comfort. The effect of controlled shades to control unwanted solar gains is also explored. Results show that passive solar buildings, in particular, can benefit from increased air circulation with a forced air system because it allows solar gains to be redistributed and thus reduces direct gain zone overheating and total energy consumption.
Article
In this paper, a new method entitled “BBEE (Building Blocks Energy Estimation)” for estimating energy performance at the district level is proposed. It consists of two branches, namely the BBEE algorithm and an energy database of a typical zone. This method is used to keep architects and urban planners informed of the energy performance of their design by clustering zones and looking up corresponding energy intensities from the database. Because the related energy databases are preexisting, energy performance modeling and simulation are not required from the user. On the other hand, the database is set up and continuously replenished by parameterization simulations with a basic model of typical zones. This task was separated from the estimation process and operated by experts, which shortened the process and reduced modeling errors. As a case study, an urban district with eight buildings was estimated under three climate conditions separately following the proposed BBEE method. Results were compared with the full-model simulation using a simulation tool called DeST. The difference in annual heating demand between estimation and simulation was reported as less than 6% in all three cases. The potential applications and limitations of the proposed BBEE method are discussed at the end of this paper. Although further improvements are still required, the new estimation method could be helpful for energy performance estimation at the district level at the early stage of design.
Article
Urban-scale building energy modeling (UBEM)—using building modeling to understand how a group of buildings will perform together—is attracting increasing attention in the energy modeling field. Unlike modeling a single building, which will use detailed information, UBEM generally uses existing building stock data consisting of high-level building information. This study evaluated the impacts of three zoning methods and the use of floor multipliers on the simulated energy use of 940 office and retail buildings in three climate zones using City Building Energy Saver. The first zoning method, OneZone, creates one thermal zone per floor using the target building’s footprint. The second zoning method, AutoZone, splits the building’s footprint into perimeter and core zones. A novel, pixel-based automatic zoning algorithm is developed for the AutoZone method. The third zoning method, Prototype, uses the U.S. Department of Energy’s reference building prototype shapes. Results show that simulated source energy use of buildings with the floor multiplier are marginally higher by up to 2.6% than those modeling each floor explicitly, which take two to three times longer to run. Compared with the AutoZone method, the OneZone method results in decreased thermal loads and less equipment capacities: 15.2% smaller fan capacity, 11.1% smaller cooling capacity, 11.0% smaller heating capacity, 16.9% less heating loads, and 7.5% less cooling loads. Source energy use differences range from -7.6% to 5.1%. When comparing the Prototype method with the AutoZone method, source energy use differences range from -12.1% to 19.0%, and larger ranges of differences are found for the thermal loads and equipment capacities. This study demonstrated that zoning methods have a significant impact on the simulated energy use of UBEM. One recommendation resulting from this study is to use the AutoZone method with floor multiplier to obtain accurate results while balancing the simulation run time for UBEM.
Conference Paper
A new approach to building modelling software, to support the iterative design of energy efficient buildings, is proposed. The proposal is for the combination of two, previously separate, software types - building design modelling and building performance simulation, along with the development of a third component - a design advisor, into one software tool. This software is intended for use by architectural practices, who may not have access to energy expertise, and who may then struggle to maintain design standards for non-domestic buildings required to satisfy rigorous energy performance regulations. In this paper we describe, through an example, how the three components would work together, by the employment of zone meshes, to visualise, simulate and support with information and advice, the design of a building. The novelty of the method resides in the application of underlying zone meshes for the support of iterative building design. The approach is described, illustrated and future work outlined.
Conference Paper
This paper examines how well a DOE 2.1B simulation which has been calibrated for a 20,000 square foot building reflects actual end-use energy consumption. Empirically measured data are compared with simulation results for end-use energy consumption, heating and cooling loads by thermal zone and month, monthly energy use, and monthly peak demand. The limitations of the DOE 2.1 code with respect to modeling the heat pump system are discussed and implications analyzed. An examination of schedules used to model the building highlights the importance of accurate information about building operation and its impacts on the simulation results.
Book
Mechanical and electrical systems for large buildings are discussed in detail. The book is designed to help engineers and architects. Special attention is given to heating and cooling systems, temperature and humidity control systems, power distribution systems, ventilation, lighting, energy management, and to pumps, boilers, fans, and plumbing. There are also chapters on protection from radiation, solar energy, and central heating plants.
Article
This research investigates the impact on energy use of the different ways in which office spaces can be organised and used. It explores typical UK office layouts, utilisation densities and intensities on a good practice-base case shell. This is achieved using the TAS, Lightscape and Excel software packages. For the average occupancy of 50%, the analysis indicates that the variations in combined thermal and lighting loads are 19% and 51% during the UK peak winter and summer respectively. The respective per capita load variations are 80% and 16%. The analysis demonstrates that space planning and utilisation have significant impacts on energy use and are important in assessing energy performance.
Article
There is a tendency for Australian energy efficiency design guides to locate bedrooms of houses in temperate climates on the south, and concentrate on assuring solar access and thermal comfort in the living rooms, which are thus locatedon the north. The National Evaluation of Energy Efficient Houses or NEEHA research project (Ballinger, Samuels, Coldicutt, Williamson and D'Cruz, 1991) shows that occupants prefer to have winter sunlight and daylight penetration in bedrooms as well as living rooms. Indeed, the highest levels of discomfort recorded in each of the four city-regions/states are shown to be related to dissatisfaction with winter temperatures and sunlight penetration in bedrooms.Energy consumption will increase where occupants are not prepared to tolerate thermal discomfort in their bedrooms. In other words, the thermal expectations and experiences of users tend to have a direct impact on energy use, and, ultimately, on environmental sustainability.There are rational alternatives to locating bedrooms on the south of a house, which could resolve both comfort and energy issues. It is the ‘design preconceptions’ of designers, builders and authors of design guidelines which need to be re-evaluated in the light of this new user-based knowledge.
Article
The method of calibrated computer simulation is summarized on the basis of related literatures and guidelines. It is used to analyze the energy performance of a high-rise commercial building in Shanghai, China. DOE-2 energy model is built up with the detailed data of building and system that are collected on as-built drawings, specifications, operating records and site surveys. Model calibration is conducted on the comparison between simulation output and measured energy use. Energy model is adjusted until statistics indices are met in compliance to applicable standards and guidelines. Calibrated model is used in the performance analysis for energy conservation measures (ECMs) that are about to be implemented in the retrofitting project of the high-rise, including using variable speed chilled water pumps instead of constant variable speed ones, using free cooling during winter and mild seasons, decreasing lighting power densities. Energy saving performance is simulated and calculated to find out which ECM is the best option for the building.
Article
This report reviews the reported uncertainty of the DOE-2 simulation program by reviewing the published accuracy of DOE-2 simulations versus: measured data (Empirical Validation), other simulation methods (Comparative Test), and analytical calculation (Analytical Verification). This report includes a review of the history of the DOE-2 simulation program. In summary, from the literature it was found that DOE-2 simulations versus measured data were shown to vary by 10% (reported in 33 of 47 studies) to 26% (reported in 14 of 47 studies). DOE-2 simulations versus simulations by other programs showed agreement in the 1% to 30% range, and from 1% to 15% when weighted by building size. DOE-2 predictions of whole-building energy use versus analytical calculations were shown to vary from 0% to 5%. One report that focused on component modeling showed that DOE-2 versus analytical calculations varied from 0.2% to 18.7%. This literature review covers the DOE-2 simulation program, which is one of the legacy programs in the ESL’s Emissions Calculator (eCalc), a web-based emissions reductions calculator. The eCalc program is a tool for those who want to see how their energy savings have reduced NOx emissions, which are produced by on-site combustion of natural gas, or at fossil-fuel burning power plants that supply the electricity. This report includes a brief history of the development of the DOE-2 program, and includes an analysis of the reported accuracies of the DOE-2 program. For the validation of the DOE-2 program, peer-reviewed literature that presented case studies using one of three methodologies (empirical, comparative, or analytical) were reviewed and summarized.
  • U S Eia
U.S. EIA., Annual Energy Outlook 2018, DOE, Washington, D.C.: U.S., 2018.
Towards a zero-emission, efficient, and resilient buildings and construction sector: Global Status Report
  • T Abergel
  • B Dean
  • J Dulac
T. Abergel, B. Dean, J. Dulac, Towards a zero-emission, efficient, and resilient buildings and construction sector: Global Status Report 2017, United Nations, 2017.
  • L Pérez-Lombard
  • J Ortiz
  • C Pout
L. Pérez-Lombard, J. Ortiz, C. Pout, A review on buildings energy consumption information, Energy Build. 40 (2008) 394-398.
Model based cost and energy performance estimation during schematic design
  • V Bazjanac
V. Bazjanac, Model based cost and energy performance estimation during schematic design, in: 22nd Conference on Information Technology in Construction, Dresden, Germany, 2005, pp. 677-688.
Development of a reference building information model for thermal model compliance testing-part I: guidelines for generating thermal model input files
  • S Kota
  • F J F Stipo
  • J Woonseong
  • K Jong Bum
  • J L B Alcocer
  • M J Clayton
S. Kota, F.J.F. Stipo, J. WoonSeong, K. Jong Bum, J.L.B. Alcocer, M.J. Clayton, et al., Development of a reference building information model for thermal model compliance testing-part I: guidelines for generating thermal model input files, ASHRAE Trans. 122 (2016) 256-266.
Development of a reference building information model for thermal model compliance testing-part II: test cases and analysis
  • F J F Stipo
  • S Kota
  • J Woonseong
  • K Jong Bum
  • J L B Alcocer
  • J S Haberl
F.J.F. Stipo, S. Kota, J. WoonSeong, K. Jong Bum, J.L.B. Alcocer, J.S. Haberl, et al., Development of a reference building information model for thermal model compliance testing-part II: test cases and analysis, ASHRAE Trans. (2019).
Mechanical and Electrical Equipment For Buildings
  • W T Grondzik
  • A G Kwok
W.T. Grondzik, A.G. Kwok, Mechanical and Electrical Equipment For Buildings, 12th ed., John Wiley & Sons, Inc., Hoboken, NJ, 2014.
Engineer's HVAC Handbook: A Comprehensive Guide to HVAC Fundamentals
  • G Hamrick
G. Hamrick, Engineer's HVAC Handbook: A Comprehensive Guide to HVAC Fundamentals, 2nd ed, Price Industries Limited, 2012.
Description of the program and details of the load program, in: USPS symposium: Computer program for analysis of energy utilization
  • M Lokmanhekim
M. Lokmanhekim, Description of the program and details of the load program, in: USPS symposium: Computer program for analysis of energy utilization, Washington, D.C., 1971, pp. 29-79.
A comparative validation of the long term energy consumption predictions of five residential building energy simulation programs in a heating climate
  • L F Goldberg
L.F. Goldberg, A comparative validation of the long term energy consumption predictions of five residential building energy simulation programs in a heating climate, in: Building Energy Simulation Conference, Seattle, WA, 1985, pp. 282-289.
Influence of Thermal Zone Assumptions On DOE-2 Energy Use Estimations of a Commercial Building
  • S B Hinchey
S.B. Hinchey, Influence of Thermal Zone Assumptions On DOE-2 Energy Use Estimations of a Commercial Building, Texas A&M University, College Station, TX, 1991.
Symposium on Simulation for Architecture and Urban Design: Society for Computer Simulation International
  • L Smith
  • K Bernhardt
  • M Jezyk
L. Smith, K. Bernhardt, M. Jezyk, Automated energy model creation for conceptual design, in: 2011 Symposium on Simulation for Architecture and Urban Design: Society for Computer Simulation International, 2011, pp. 13-20.
Beyond the shoebox: thermal zoning approaches for complex building shapes
  • L Smith
L. Smith, Beyond the shoebox: thermal zoning approaches for complex building shapes, ASHRAE Trans. 118 (2012) 141-148.
Straight skeleton implementation
  • P Felkel
  • S Obdrzalek
P. Felkel, S. Obdrzalek, Straight skeleton implementation, in: Spring Conference on Computer Graphics, Budmerice, Slovakia, 1998, pp. 210-218.
Investigating an adequate level of modeling for energy analysis of domestic buildings, 3rd Asia Conference of International Building Performance Simulation Association
  • Y Heo
  • G Ren
  • M Sunikka-Blank
Y. Heo, G. Ren, M. Sunikka-Blank, Investigating an adequate level of modeling for energy analysis of domestic buildings, 3rd Asia Conference of International Building Performance Simulation Association, 2016.
Post Office Energy Analysis Program
  • U S Usps
USPS, U.S. Post Office Energy Analysis Program, United States Postal Service, Washington, D.C., 1971.