Understanding Virtual Enviornment

IES Virtual Environment is a comprehensive energy modelling and environmental analysis tool which can simulate just about everything happening to your building. Past use of Virtual Environment existed mostly outside of the architects' realm, however IES has done much recently to integrate their tools into the architectural process with push-button toolkits.

The strength of the toolkit is that it can be embedded into architectural design programs (Revit & Sketchup so far) and with a modified workflow one is capable of achieving truly integrated and iterative analysis.

The toolkit performs a series of independent analysis which makes it less comprehensive than the full Virtual Environment. The full suite contains an array of modules, each performing different tasks that are capable of feeding back into the main energy model. For example, if your project will utilize daylight harvesting you would first run daylight simulations and then link these results back into the thermal simulation module where you can see the energy impact from reduced cooling loads and electricity use. The process is similar for natural ventilation and solar shading analysis where separate modules link their results to the main thermal simulation engine. Even HVAC systems design can feed into the central energy model for collaborative A/E BIM analysis in a central model.

It is not immediately apparent where Virtual Environment falls in the traditional A/E firm structure and project workflow. What is apparent is that the ultimate success of its use requires a process shift in either the way the architect designs and delivers, or in the roles assigned to the mechanical and energy engineers (US in particular). Either way there must be time, budget, and client expectations to ensure that this level of collaboration succeeds.

Understanding Ecotect

Ecotect is a studio companion that enables designers to better understand the relationship between buildings and their environment. As a visualization tool Ecotect interactively displays sun and shadows, solar rays, sun path diagrams and much more.






As an analysis program there are 3 common methods for calculating and visualizing data:

• Analysis Grid (of points)


• Analysis Surfaces


• Thermal Analysis of Zones

Analysis Grid

The Analysis Grid is a single 3-Dimensional grid able to collect data over points in space. The analysis grid is used for analysis where the collected values are not interested in surface area or the sun angle. Common analysis here includes internal daylight levels, external sunlight hours, airflow and others. All of the solar related functions can be done within the program itself but for advanced daylighting and CFD airflow Ecotect links up to other programs, many of which are free to use.

Analysis Surfaces

Analysis surfaces are used to calculate and visualize solar issues that are relative to the sun angle. To understand the difference between this and the analysis grid just think that when a surface closer to being perpendicular to the sun it will read higher solar gain values, by contrast points have no area and will all show the same readings for any period of time exposed. Surface solar analysis is very helpful for early massing and orientation studies, as well as facade design.

Thermal Analysis

Ecotect is one of many energy modeling programs, most of which have different calculation methods and intended uses. The strength of Ecotect is with comparative design analysis where you can modify building geometry or attributes and see the relative impact on performance. For more advanced simulations Ecotect can export to other energy modeling programs with varying degrees of successful interoperability.

There are of course more analysis options in Ecotect than those briefly mentioned here, and if you wish to learn more head over to the Ecotect wiki: http://www.squ1.org/

BIM Use:

Ecotect very easily re-uses data from other programs as long as the models are either very simple or easily able to be reduced to the basic elements needed for analysis (see previous blog on this subject). Ecotect is able to import BIM room objects which are converted into zones for thermal and daylighting analysis. A small to moderate amount of manual cleanup is needed at this point in time depending on the BIM authoring tool used to produce the model (Revit, Archicad, etc).

Design Analysis Workflow

This post has moved to the following blog:

http://greenbimnetwork.blogspot.com/

Revit Architecture to IES Workflow

The IES Revit VE (Virtual Environment) Toolkits are ideal for use at the very early stages of the design process to provide quick assessment options for architects and engineers alike.

At early stages in projects up to 70% of the design decisions which affect performance have been made. The Sustainability Toolkit, performs the sustainable design analysis that is so important at these early concept stages – energy use, carbon use, daylighting and solar performance. Helping the design team establish the most appropriate sustainable and energy efficient approach. The following steps provide a quick guide to installing, setting up your Revit model and utilising the IES VE Toolkits.

Installation:

1. Download the plug-in from IES, currently in Beta

2. Ensure applications are closed

3. Remove via Control Panel IES if it exists.

4. Install V:\Other\IES\2007-12-12 IES Toolkit for Revit\ve5850.exe

5. The following tool bar appears in Revit

Preparing Revit model:

1. Add Room objects to your project.
2. It is important that the Rooms in Revit are built correctly and bounding on all sides, otherwise the results will not be accurate. For full details see this IES guide.
3. In Revit select Settings > Room and Areas Settings > and turn on “Compute Room Volumes”
4. Save project

Using the plug-in

1. Select > Set Model Properties, this may take a few seconds to load
2. Switch to Building Type tab
3. Select default room construction
4. Select building services system
5. Select place and location
6. Switch to Rooms tab
7. You are then able to override the room construction and room services system (this can be left as default for initial run)
8. Use left mouse button to orbit model (unlike shift and mouse wheel in Revit!)
9. Select > Check Model…and Review the IES Report (if issues exist return to Revit to fix)
10. After Check of Model is OK, check “I have checked the model is suitable for analysis”
11. Select OK, this returns to Revit
12. Select Toolkit
13. Run the LEED Toolkit to get results. IES LEED Toolkit features (Other Toolkits can be run too)

Suggestions:

Start of with a really small project, maybe only a couple of rooms and really understand what is being analysed and how changes in your model are being reported by the IES analysis tools.

Try File >Export > gbXML first to check your rooms are complete. (IES uses gbXML from Revit Architecture)

Questions:

How does IES know the north rotation - as at no time did I specify this, I assume it uses project north and ignores Revit true north if set in the project?