Autodesk Ecotect Analysis Software
In an era where global consensus seems to be demanding very aggressive goals for energy performance such as net zero-buildings for new constructions, there is great urgency for building performance simulation and analysis tools that are able to model building performances in all their real world messiness. According to the United States Department of Energy (2009), construction and building industry accounts for 38% of carbon emission and 40% of the total energy consumption in United States (Peng & Wu, 2015). Such features portray the great environmental impact that the building sector projects.
Engineers and architects are required to consider environmental impact whenever they engage in a building project in order to conserve energy and reduce carbon emission effect. Many countries have clear policies and legislations that check architectural and engineering projects in order achiever better and sustainable infrastructure.
This paper provides a comprehensive description of environmental software that simulates environmental data in order to create significant basis for important decision making in building and construction projects. The paper projects rationale for the creation of the software tool and technical information with regards to its development. It describes the software’s function and limitations in relation to different projects that it has facilitated.
Historical Background of the Software
The software was created and developed by Dr. Andrew Mash and Square One Research Ltd based on the Isle of Man in United Kingdom and later acquired by Autodesk. The company was founded in the year 2000 with the aim of supporting and promoting the development of leading-edge simulation and analysis solutions through software development, research publication, and on-line education resources. The software giant, Autodesk, purchased the software on 28 June 2008 purposely to facilitate better integration into the BMI models of building design products. Alongside Ecotect, Autodesk also purchased Green Building Studio (GBS).
Autodesk Ecotect Analysis is a design and performance analysis tools that helps in environmental analysis (Peng & Wu, 2015). It enables designers to make simulations of building performance from the conceptual stage of project design. This software offers a wide range of environmental simulations, which includes building energy analysis applications to simulate and visualize the performance of a building within the context of its environment.
Why the Software was developed
After several studies pointed the building sector as the major contributor to global environmental deterioration, there was needed to create a software tool that could enable designers deliver sustainable green project. Square One Research Ltd and with the help of Dr. Andrew Mash come up with a software tool that could provides design and performance analysis solution to enable the designer conceptualize the performance of the buildings in their initial stages; Autodesk Ecotect Analysis software. The software was developed by collaboration of engineers and architects in order to provide significant support when designing buildings.
In the modern era, sustainable design is more demanded than ever (Erickson & Talbert, 2014). Engineers and architects in this are like using performance data offered by environmental design decision support tools (EDDST). These tools enable designers make buildings that have better performance and significantly meet real world performance goals. Autodesk Ecotest software is designed to be utilized during conceptual and initial stages of the design process in order to foster allocation of resources using information related to water, energy, and other metrics during the scheme selection process (Peng & Wu, 2015).
Other simulation and performance analysis software includes: HEED, Energy 10, HTB2 DOE-2, DEROB-LTH, DOE-2, EnergyPlus, eQuest, Design Builder, Green Building Studio (GBS), ESP-r, IES VE, and Energy Plus-Sketch Up Plug-in (Peng & Wu, 2015). Among the many software that provide simulation and performance analysis, only few applications are compatible with BIM-based design software. Autodesk Ecotect is BIM-based design software along with other software such as; Green Building Studio and IES VE.
How it Works
The software saves engineers and designers a lot of manual calculations which were normally done during energy analysis (McConahey, 2012). Energy analysis makes use of spatial information which is essentially a simulation of energy motion in, out, and through the building rooms and all volumes within a building. Traditionally, before the creation of Autodesk Ecotect, the information was analyzed and calculated manually using 2D drawings (McConahey, 2012). The engineers would make use of building plan, surfaces (including thermal properties and adjacency), shading, and elevations and precise details to collate architectural spaces (Volume, type and area). This was cumbersome process that required a lot of attention and consumed a lot of time. The engineers were expected to consider questions such as: Which surfaces are exposed to the outside? How many surfaces are exposed to the sunlight? What are the size, orientation and number of openings in every space? How much heat is generating from the interior, that is, from equipments and internal lighting? Autodesk relieve the designers and engineers unnecessary inclusions because much of the information is latent in a simple model and in manner that is easier to interpret than2D drawings.
The software tool has a very user-friendly interface that permits easy manipulation and construction of 3D models. The user can make importation of 3D models in 3ds or (.dxf) format from various computer aided design software such as Rhinoceros, Sketchup, AutoCAD and 3D Studio (Peng & Wu, 2015). This interfacing facilitates wide communication flexibility which enables interaction with ArchiCAD and several other modeling and simulation tools.
Fig 1. 3D Modeling of Building (Autodesk Ecotect Screenshot)
The figure 1 below conveys 3D model being manipulated using Autodesk Ecotect. Normally, data is presented as grey layer or gradient color on top of a 3D building geometry. Models can be present in various ways and from different vantage points. The manner in which the advanced graphical interface in this simulation tool culls extraneous information to reveal the information that is required to evaluate a particular condition makes Autodesk Ecotect Analysis software unique and better than other software (Peng & Wu, 2015).
Different inputs are required for different functions. For example, when conducting energy simulation, the input required when conducting energy simulation with the software includes: geometry, internal set point temperature, material and surface properties, weather data for specific location, period and use of internal sources.
Figure 2. Workflow to produce a thermal simulation model
The simulation program has an engine that facilitated simulations based on simple text-based inputs and output files (Erickson & Talbert, 2014). The engine contains mathematical algorithms that facilitate processing of the input data into a meaningful output. Normally, the engine makes use particular input files that contains important representation of the input. Based on these inputs, the software tool works out simulations and makes its output into one or more output files. The engine is majorly used to facilitate construction design process by comparing different design elements.
Figure 3. General input data of thermal simulation engines
As shown in the figure 3 above, the output of the thermal simulation engine is comprehensive information that represents an integrated model. Normally, the simulation or output data is represented as codes, graphs or text, and in a format that can allow other programs analyze or make further modification.
Fig 4. Weekly Weather Analysis using Ecotect
Ecotect is a powerful weather tool that allows users analyze, visualize, and conduct hourly editing of weather data as conveyed in the figure 4 above. The accuracy of simulation is normally determined by the input data. Practically, the data originates from external and internal parts of a building when doing simulation such as thermal simulation. When working on external loads, it is important to consider the effect of climate and weather. Therefore, collected and assemble weather data are normally utilized in energy performance simulation. Weather data file are coupled in the software tool in order to give an output based on available conditions (McConahey, 2012). The weather files are created in a manner that does not reflect specific year, but provides vital numerical reference for a typical weather parameters of a certain location. During commissioning or operation process, weather information can be calculated directly at the construction site in order to ensure actual figures are included in the simulation process. Internal loads, which includes loads from equipments, lights and people in a space significantly depends on the actual usage of the architectural space and the activities of its occupants.
Fig 5. Building Location using Autodesk Ecotect
Google Maps API technology is integrated in the software to facilitate easy location of the building position and vital weather conditions of the region identified. The figure 5 above illustrates the “location” of a particular building through Autodesk ecotect software.
The software is able to precise measurement of overshadowing effect through calculating the exposure with and without nearby buildings (Peng & Wu, 2015). Once the difference between the two is expressed in percentage form it reveals the overshadowing effect. Solar radiation is the chief source of passive heat energy available in any architectural project. Autodesk Ecotect is able to create sun path diagrams for solar radiation analysis. The figure 6 below conveys an interactive sun-path diagram on a side by side view of 3D model.
Fig 6. Overshadowing effect (Autodesk Screenshot)
Benefits of Autodesk Ecotect Analysis Software
Autodesk Ecotect Analysis offers an expanded array of environmental analysis. Ecotect offers wide array of simulation and analysis options, which includes: shading design, shadows and reflection, lighting design, thermal analysis, right-to-light analysis for neighboring buildings, photovoltaic array sizing and load matching, ventilation and airflow and acoustic analysis (Peng & Wu, 2015). One of the uniqueness of Autodesk Ecotect compared to other Environmental software is that it targets the earliest stage of design. Decisions made in the early stages have great impact and far-reaching effect on the final project.
The software offers BIM(Building Information Modeling) solutions that facilitate sustainable design practice by enabling engineers and architects to make more accurate simulation, analysis and visualization of building performance earlier in during the design process. The intelligent tool in the BIM enables the advanced functionality of the desktop and well-based functionality which are included in the Autodesk Ecotect Software. By using this software, designers and architects are able get better insight into expected performance of a building earlier in the process, enabling sustainable design, lower project costs and faster time to market (Erickson & Talbert, 2014).
The release of version 5.6 provided added support for gbXML and IFC schema. This version can perform more applications such as sound analysis, daylight analysis and better visualization. Also, an important feature in this version is that it can import models from other CAD software such as; AutoCad, 3DsMax and ArchiCad. On the other hand, Autodesk Ecotect can export to several other programs and CAD formats (Peng & Wu, 2015). Export is supported to ray-traced rendering, GBS, eQUEST, POV-Ray and (.wrl), (.dxf) format, and EnergyPlus. The figure 7 below indicates the import options in Autodesk Ecotect.
Fig.7 Autodesk Ecotect Import Geometry
Autodesk Ecotect allows simulation of the whole building in 3D (Peng & Wu, 2015). This is one of the benefits that this software tool has over other applications. The 3D based programs can facilitate three dimensional visualization environmental attribute which is not visible in architectural space. Therefore, more effective understanding of environmental performance of the building can be achieved through the 3D based program.
Data swap between Ecotect and Revit can be done using gbXML (Green Building XML) which is a schema specifically created to facilitate transfer of building properties stored in BIM to an analysis tool (McConahey, 2012). The basic structure of gbXML includes elements such as walls, rooms, floors, windows, ceiling and shading surfaces.
As indicated in the figure above, Autodesk Ecotect is able to display and animate complex reflections and shadows, generate interactive sun-path diagrams for vital overshadowing analysis, and make calculations of incident solar radiation on the surfaces. The software is able to calculate hourly temperature graphs and monthly heat loads for any time zone (Peng & Wu, 2015). Though outer wall and roof placements tend to be most problematic elements, the software is able to export to a greater number of programs and CAD formats.
Though Autodesk Ecotect’s thermal simulation results are considered in making significant designing decisions, they are not fully representative of reality. The main reason behind this limitation is that the weakness of its thermal simulations engine which is based on the CIBSE Admittance method. Autodesk Ecotec Analysis software makes use of thermal performance analysis based on CIBSE (Chartered Institute of Building service Engineers) admittance method and therefore inherits all its limitations (Erickson & Talbert, 2014). Normally, the software makes use of this method to calculate heat load and internal temperature. Admittance method is a kind of pseudo-dynamic method which is normally based on variation about the mean value (McConahey, 2012). The method does not take into consideration the impact of solar radiation when in enter the architectural space. Solar radiation is normally considered a space load the moment it touches or hits the window and is not traced again to check which internal surface it hits and according to heat up.
Though the software is user-friendly, the interface in its application is complicated and require substantial amount of experience in computer modeling for the user to be able to relate appropriately with the Software tool (Erickson & Talbert, 2014). Therefore, it may take some time for a person to master it. This aspect limits the integration of simulation within the architectural design process.
It is quite difficult to input building geometry into the software tool and interpolate the simulation results. The models in some cases have to be introduced in a textual format in order to be processed. This often leads to inaccuracy due to increased human error during data input stage. Also, the process consumes a lot of time and normally requires advanced knowledge in programming.
During exportation and importation of files, wrong models may result to display of numerous error messages. In most cases, these messages do not provide sufficient explanation and guidance on how to fix the fault in the model.
Another major limitation on software tool is that it cannot make calculations of thermal lag for composite elements which are not included in its library (McConahey, 2012). Although the software material library includes majority of the typical components used building and construction industry, it does not cover a wide range of components and materials used throughout the world, and especially outside Western countries. As a result of this aspect, the program seems to favors designers working within the regions of Western countries. This burrs the users from optimizing their innovations in construction and therefore entirely inhibits the most fundamental requirement of computer simulation.
3D model can be directly made Using Autodesk Ecotect or alternatively imported from other software such as Rhinoceros in DXF, Sketchup or AutoCAD (Kulahcioglu, Dang, & Toklu, 2012). However, importing files from other software result to large files that normally affect simulation speed. In other cases, exported files might lead to complex Ecotect models that are not suitable for perfoming thermal simulation and prone to errors.
Better Alternatives Application and Future Development
As a result numerous limitations of Autodesk Ecotect in thermal simulation, it is vital to create a more detailed thermal simulation tools that can favor designers from any part of the world. In the move to develop better software tool that matches the current needs in building and construction industry, Autodesk decided to replace Autodesk Ecotect Analysis software with a more advanced software tool that facilitated better energy efficiency and high performance design. Autodesk shifted its resources to Revit product family in order to maximize performance capabilities. Development efforts on cloud-based solutions and BIM for building performance visualization and analysis brought about the new version of Revit (Peng & Wu, 2015). This move was supported by several benefits expected in the Revit environment.
Solar Analysis: Revit include a solar analysis plug-in that has a more sophisticated algorithm than that of Autodesk Ecotect Analysis software. With the new plug-in, analysis is entirely integrated with Revit (Peng & Wu, 2015). Users are able to quantify and visualize the distribution of sun radiation for any time and date with direct display of the model results.
Sun and Shadow Studies: Revit allows appropriate visualization of sun path due to inclusion of interactive sun path tool in the software. This enables the user to study effect of shadows and natural light on both inner and outer part of the building project for any location.
Day lighting and lighting: Revit is able to perform electric lighting and day lighting analysis using a better lighting analysis mechanism. This analysis makes use of the Autodesk 360 Rendering to project solar and electric lighting outcomes directly on the Revit model (Peng & Wu, 2015). Lighting analysis in the new software tool allows the user to input time, location and user preferred sky model.
Thermal performance: Revit was carefully designed using provisions of the ASHRAE Handbook of Fundamentals to include cooling and heating load features. This enables the user calculate thermal loads taking into account solar stress, internal loads and the impact of building envelope. The user is able to calculate cooling and heating loads for models and make analysis of the effect of internal gain, occupancy, equipment, and infiltration.
Whole Building Energy Analysis: Revit has significantly improved integrated Energy Analysis to enable more detailed building elements. The analysis enables the user to calculate total energy cost and use on hourly, daily, monthly and annual basis by use of global database that provides valid weather information (Peng & Wu, 2015). The new software tool enables the user to customize the visual representation of data.
Weather Data Visualization: This functionality is provided by Revit with better performance. The weather files are derived from the Autodesk Climate Server which sufficiently supplies valid data.
Design and analysis tools play a significant role in the modern building industry. The environmental impact of the modern designs is a key factor that prompts more inputs in creating better software tools that meets the future demand. Innovations of better tools that can take advantage of the cutting edge 3D model help building designers visualize simulation outputs is necessary. Autodesk Ecotect Analysis is user-friendly program tool that can import and export from a wide variety of other software. Interoperability through simulation tools offers better solution to the problems of integration. It significantly reduces the time required to develop a building and creates and assurance that once the building operation commences it will meet the design intent. In spite of several limitations, Autodesk Ecotect is certainly a very powerful simulation tool that can help in sustainable building design. Though it is hoped that the next version will integrate a great deal of new capabilities, the current version has significantly contributed towards achieving sustainable designing.
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