Tips & Tricks - TRACE 3D Plus

Published 08/29/2017 01:58 PM   |    Updated 04/10/2024 04:14 PM

General suggestions:

• Try to keep your models simple and refine with more detail after validating the simpler model runs as expected. The standard templated values in TRACE include industry used/accepted values that can help guide you to a good load design or energy model. A good rule of thumb is that "If it wouldn't have been modeled in TRACE 700, it probably doesn't need to be modeled in TRACE 3D Plus".  The only exception to that is probably with internal wall partitions that are used for room boundary/area definition because they come by virtue of drawing adjacent interior spaces.
• Comparing TRACE 700 to TRACE 3D Plus can be difficult. It's understandable that matching results between the two programs will help validate that TRACE 3D Plus meets the desired needs and fidelity. However, keep in mind that the engine and the interface assumptions in many cases are quite different. Sometimes the differences are easily explainable and in other cases a great deal of time can be spent without a definitive answer, so please keep this in mind as you explore your results.

When tracing over floor plan images:

• For plan images that are not uniform with each other, use known geometry on other levels in tandem with snapping to align accurately.
• When drawing multi-level buildings, start with Level 00 (default level) and work your way up above grade, and work your way down below grade.
  • Try to reference structural walls from the level below (or level above when building down below grade) as guides/snaps for room creation even if floor plans may not perfectly align. This will help keep the number of drawing snaps to manageable level making it easier to create walls as the model becomes more complex and reduce error due to misaligned plan images, while reducing calculation time by reducing the total number of surfaces that must be processed by the engine.
• Make sure to utilize the available snaps to get the first room in the building drawing square with the drawing canvas axes - the best way to guarantee this is to use the rectangle tool for the first room, if possible, to ensure walls are aligned with the axis that you can snap to later.
  • Snapping indicators reflect the vertex, edge, wall projection or midpoint that is being snapped to.  
  • Yellow indicates the snap is to the active level, where blue indicates the reference level selected as "Show Level Outline for" from Grid Settings.
  • Snaps reference only geometry displayed within the drawing canvas. To prevent a specific snap without disabling it, move it out of view using pan or zoom tools.
  • Snap can be enabled or disabled while actively creating rooms to aid in accurate placement.
• Shift will pull polyline plumb with the axis during active placement
• Verify the toolbar configuration prior to any room creation, especially when returning to Create Building
• Check the drop ceiling or raised floor check box before room creation 
  • If you forget to do this before room creation you can still add either through the room properties or Edit Wizard.
• Occupiable room areas and volumes may be challenging to match exactly for each room due to manual image scaling. To simplify complex building geometries TRACE 3D Plus allows for consistent wall thickness for the entire facility. Once a project has been created, wall thickness for any wall that is created is locked-in and cannot be changed in the drawing model. For most buildings this is a good approximation and is much better than many other modeling tools that simply utilize single centerline models, specifically for area-based loads and ACH airflows
  • Wall thickness does not impact the surface thermal analysis or mass calculations, it impacts only occupiable area/volume and dependent variables such as loads and airflows.
  • The library member selected represents the actual thermal properties of any given wall construction
• The polyline room creation tool can be used to create complex geometric room or zone shapes by either clicking consecutive lines until a room is enclosed or by enclosing various openings until a new room or zone is completely enclosed (useful for complex hallway shapes).
• • If you misplace a vertex while drawing multiple walls with the polyline tool you can undo previous vertex placements by using "CTRL-Z" on the keyboard. You can use this feature multiple times for a single polyline room construction. There is no other undo feature in the program.
  • Use the zoom tool (mouse wheel is typically easiest) to pinpoint vertex placement with respect to plan images.
  • Use the fixed polyline tool to approximate arced walls.
  • If walls that do not completely enclose a room are created, when navigating away from the drawing canvas, any walls and vertices that do no enclose a room will automatically be removed and the polyline drawing action will be cancelled.
• If you draw a room using either the rectangular room creation tool or the polyline drawing tool and the room disappears it means the room was not created. This will generally not impact your model and you can continue to try to create the room using alternative methods. There are several ways that this might happen. If a room fails to get created try recreating the room from an alternate direction or selection of other snaps points.
• If a room does not get created properly (e.g. walls snapped to the wrong point etc.) try deleting the room and recreating it. If a vertex is created that continues to cause snapping issues, you can delete the room and/or try closing and reopening your file. Hanging walls or vertices will be removed when the file is closed and reopened.
• Rooms that do not have an exterior exposure (e.g. at least one outside wall) cannot be deleted without first deleting surrounding rooms that will make one of the existing rooms walls an exterior exposure. 

Systems and plants tips:

• Systems and plant properties cannot be edited from the Create Systems or Create Plants subsections. All properties on theses screens will be read-only.  
• The only DX systems that require a plant loop are VRF and WSHP systems.
• When creating custom systems or plants be sure to use the validation tool (eyeglass) to ensure there aren't any connection or other validations rule violations that may cause the simulation to fail.
• Assigning controllers is a new concept for TRACE 700 users. In TRACE 3D Plus all coils and most plant loop equipment will require a controller hooked between a control point on the air/water loop and connected to the coil or plant equipment. The validation tool will capture any errors with controller connections.
• When running a calculation, if you get a severe error when calculating that a coil is missing or not connected to a system or if a system has not been properly connected to plant try un-assigning and re-assigning the object in question. In the case of a single chilled water, condenser, and/or hot water loop, try using the auto-assign systems to plants feature.
• When changing fans or pumps, the fan static pressure or pump head you may have previously entered will be over-written by the newly selected library.
• When using cold supply air (52°F or colder), use a detailed coil model rather than a simple coil. This will help avoid possible convergence issues with the simple coil model.
• Exhaust airflows must be manually balanced. If an exhaust airflow is entered larger than the calculated or entered OA to a given room or zone, then a warning will be created upon calculation. The program will often still calculate with unbalanced airflows, however if the imbalance is large enough the engine can produce erroneous results or even create a severe calculation error in some cases.

Calculation warnings/errors tips:

• Warning messages regarding calculated area and volume that can generally be ignored. These warnings are generated because TRACE 3D Plus accounts for wall thickness based on Project Default setting rather than using centerline surfaces.
• Warnings regarding coils that have 0 capacity due to low loads either in heating/cooling can often be ignored. This occurs most often in heating where a zone does not appear to need heating based on design calculations but has a heating coil. In cases where this creates unmet load hours it is often possible to resolve the issue by introducing a small infiltration load to the room or zone in question to create a coil load.

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