## Convert 2D DXF to EnergyPlus ### Import the DXF If you have Google SketchUp Pro, DXF/DWG import is already part of your application. If you have the free version of Google SketchUp 7, you can install the DXF/DWG import as a plugin that functions exactly as in SU7 Pro and SU6. You can find the DXF plugin on SketchUp's website. You must use File->Import vs. File->Open to import the file. Set the file type to (*.dwg/*.dxf), as shown below. You may also need to click "Options" to see if units are being handled correctly and scale is preserved. (Credit: David Goldwasser/NREL) Your DXF will look like this. (Credit for DXF source file: Google) The DXF/DWG layer structure is preserved. You may be able to visually clean up the model by turning off unnecessary layers. If you have an elevation with your DXF, rotate that up so you can refer to heights on it. After you select the elevation entities, pick the SketchUp rotate tool. Set the plane and origin for the rotation. A temporary cube can be made to easily pick the plane for rotation, but there are other methods as well, such as switching to a standard camera view. (Credit: David Goldwasser/NREL) Hold down the Shift key to lock in the rotation plan. This enables you to move to pick the origin without losing your rotation plane. Pick a rotation origin on the elevation that matches the floor plane for the first floor. This keeps elevation in sync with the plan. (Credit: David Goldwasser/NREL) (Credit: David Goldwasser/NREL) Set things up carefully so you can re-import updated CAD files. ### Add EnergyPlus Zones Make sure you are not in your DXF component. Create a new zone and enter into it to create the geometry. Draw the floor over the plan for your first zone. (Credit: David Goldwasser/NREL) Use the elevation to find the height for this zone. Extrude the floor up to this height. You may also use the elevation to reference window and door heights. (Credit: David Goldwasser/NREL) Add the next zone and repeat. (Credit: David Goldwasser/NREL) This is the project with the other zones added in. (Credit: David Goldwasser/NREL) The following images show the process for adding subsurfaces. Draw temporary construction lines from both the plan and the elevation to help locate and size the windows. Create guide lines using the Tape Measure Tool. Click on an edge, and drag the mouse to a reference point (vertex, or point on edge or face). A dotted guide line is created parallel to your first point and through your reference point. Turn visibility for guide lines on and off using the View menu. Delete all guide lines at once under the Edit menu. (Credit: David Goldwasser/NREL) (Credit: David Goldwasser/NREL) (Credit: David Goldwasser/NREL) (Credit: David Goldwasser/NREL) If you have the second floor plan, you can insert zones at the appropriate height and continue your modeling. You need to model the attic as a separate zone. If you plan to use automatic surface matching, be careful to line up surfaces between floors.
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