Although AutoCad is the source of many construction drawings and is recognized as a cad standard in the industry, many hvac and plumbing subcontractors do not need Autocad itself. Contractors can participate in the review and edit cycle that more projects either require or encourage or even create designs themselves by using a less costly 2D cad program. The software just has to be able to exchange drawing files with Autocad.
SmartSketch 3.0 ($495, Intergraph Process and Building Solutions, www.SmartSketch.com), for example, is a competent 2D drafting solution, with a complement of drawing tools, several predefined drawing sheets and a library of symbols. It can import Autocad and MicroStation (the other popular cad solution for construction) files and then export — after editing or other modification — back to others using those programs.
Among the 345 standard ashrae symbols preloaded into the library are symbols for air moving devices and components, annotation, auxiliary equipment, controls, energy recovery equipment, fittings, pipes, piping specialties, refrigeration and valves. There are also 102 customizable parametric Intergraph symbols, including air diffusers, air equipment, oval double line duct, rectangular double line duct reports, round double line duct and single line duct.
Editing drawings or creating drawings is straightforward. The software allows you to drag and drop symbols into drawings. Users can modify any symbol temporarily or permanently. Designers may also create and store their own symbols. The symbols automatically snap, align and rotate into position.
A Smart Connector feature allows users to connect those symbols and modify drawings while maintaining connections. Symbol behavior is associative and parametric. Users define attributes to components and may then generate schedules of materials and reports.
Because the program is fully integrated with Microsoft Office, users can include SmartSketch drawings in Word or Excel files or use report data in Excel to execute load, sizing or other design calculations. It is possible to link the files so that any change in the Excel file is reflected in the SmartSketch drawing and vice versa.
Completed drawings can be saved as SmartSketch, Autocad or MicroStation files and printed or plotted full-size.
The program is fully integrated, as well, with MathSoft’s MathCAD technical calculation software and with third party Microsoft-compatible hvac engineering/calculation packages.
Portable CAD
Jobsite accessibility to cad drawings is achievable three ways: on an onsite office desktop computer, on a notebook computer or a handheld PC.
While the desktop and notebook solutions can, with the right software, share drawings directly with the home office computer, a handheld may use specialized cad software that meshes with the platform on which the handheld runs.
Pocketcad pro ($199, ArcSecond www.pocketcad.com, 800/340-6388) is a fully functional cad software solution for users of Windows CE 2.11 or higher powered mobile devices, including pocket, palm-size and handheld PCs.
Compatible with Autocad and most other desktop cad programs, the software will allow users to download desktop cad files, view, redline, edit and, after modifications, export them back. Given the screen size of most handhelds, the drawing window is generous, covering more than 50% of the screen.
Capabilities include creating and editing layers, creating, editing and exploding block or blocks with attributes, and annotating and labeling. Users can also sketch freehand. Other editing capabilities include copy, offset, rotate, and move, and redo and undo commands. Users can zoom in and out during viewing.
There is no physical limit to the size of the files that can be manipulated in PocketCad. However, the memory capacity of the user’s handheld device and the complexity of the drawing are considerations. Some of the faster pocket PCs have used files as large as 3 MB.
If you are concerned about your handheld PC surviving some of the hazards of jobsite use, you might want to consider the new ePlate HPW-630ET, by Hitachi ($1,499, www.hitachi.com, 800/hitachi), which runs on Windows CE 2.12.
The lightweight, tablet-sized, handheld pen computer, measuring 9.5 x 6.9 x 1.5 in., has been tested to withstand falls from up to 4 ft. The unit sports a non-slip rubber handgrip and an 8.2-in. transmissive color lcd screen with dimmable back-lighting.
Running Windows CE 2.12, ePlate is equipped with a high-speed, built-in modem, a high-capacity SH-4 128-MHz risc processor cpu and a built-in graphics accelerator for high-speed performance and screen redraw. Outfitted with a usb interface, e-Plate also has a vga output for connection to an external monitor.