feature focus
Cross-Discipline ficients were generated by a separate approved program for each fitting and friction loss was calculated for each duct section by the spreadsheet. The summation of the critical duct run represents the highest static pressure required and this value was used. Using this system, when the checker and reviewer look at the spreadsheet, they can verify every duct dimension, fitting loss coefficient, quantity of fittings and airf lows. The most common errors are incorrect airf lows, incorrect duct friction factors and the wrong type of fittings (mitered elbows versus rounded, guided elbows). Using Revit, we can see in the model that the ducts look like the correct size and appear connected, but are all of the branches reporting airf low back to the air handling unit? The system browser and scheduling can get us part of the way there, but sometimes these values are not exportable to a nice clean spreadsheet for easy review. (See Figure 6)
The same is true with duct friction. Duct elbows may look correct, but is the loss coefficient table correct for this size and airf low? There is quite a bit of sifting through instance and type parameters to check some of those values. Another important consideration is not everyone on the design team will be skilled in the BIM package. It is important to provide a way for them to check progress and see the design calculations. BIM is a good example of “supply and demand.” The more we expect from software, the more research and development must go into the program development. From an architect’s and engineer’s perspective, removing duplication of effort is essential to a smarter and smoother design process. This may also make BIM adoption and integration more attractive and easier to implement. Check and re-check your work! There are many different ways to accomplish this. Hand calculations and visual checks are the tried and true method. Let’s convince the software developers that this functionality is worth their efforts and help us reduce duplication of effort. Dave Vaughn is a senior architectural technician with Stanley Consultants. Dave has spent nearly 25 years using CAD, 3D and BIM related software packages. He has been using Revit since version 4.0. A strong proponent of the platform, Dave develops company standards and content while providing technical support for projects. Coworker Marcus Matteson, a mechanical engineer also provided input for the article.
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Figure 6
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Autodesk Quantity Takeoff 2011 Released I know some time has gone by and I have personally been anxiously awaiting its arrival, so I am glad to say that the next release of Autodesk Quantity Takeoff (QTO) 2011 has been released with new updates and features. Here is a quick look at some of new enhancements (I’ll have a few blogs posts in the future to further explore some of the new features): • Edit a takeoff element or a group of selected takeoff elements from the Properties palette. • Edit DWF properties from the Properties Box • Work Break Down Structure Groups. A column for Work Breakdown Structure groups has been added to the Takeoff palette, Property palette, and Workbook. • Enable takeoff model coloring in 3D views to maintain those colors assigned in the Takeoff palette. This keeps it consistent with the coloring seen in 2D views. • Legends now accurately depict color, symbols, and fills.
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• Exporting to Excel spreadsheets is more accurate. • Network Deployment of Autodesk Quantity Takeoff installation and licensing is now supported. • Network license borrowing enabled. • Model takeoff support for Inventor DWFs. • Full Windows 7 support. • Multiple memory and performance enhancements. A quick note about installing QTO 2011. You will have to remove QTO 2010 prior to installing 2011 since some of the new updates and enhancements will not allow for a side by side installation of QTO 2010 and 2011. QTO 2011 may not install if QTO 2010 is currently installed on the system. How do you get QTO 2011? For those of your on subscription, you should be able to log into the Subscription Center (http://subscription.autodesk. com) and download QTO 2011. Otherwise contact your local reseller for more information. Subscribe to dODDS and Ends: http://doddsandends.typepad.com/blog/
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