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HVAC 4.5 Features


New Button Graphics: The graphics for some buttons were redrawn to clarify their functionality.

Automatically Turning on Duct Centerlines: Previously, any duct centerline layers that were off were turned on for various duct editing functions. Now, duct centerlines are turned on automatically only if all of them are off. If any centerline layer is on, then their layer states are not changed. When you are working in tight spaces, it is beneficial to be able to turn off the centerline of duct systems that you are not working on. This change allows you to do that.

New Layer Buttons: The buttons for controlling double-line and 3D drafting lines were improved. There are now buttons to turn them both on, both off, or one on and the other off.

Standards Files: The standards files have been changed from comma-delimited files (CSV's) to tab-delimited files (TXT's). This allows commas in fields to make information more readable.

Metric Duct Labeling: We have added the ability to support work done in metric. There is a setting in the Options window that allows you to specify if your project is using the inch or the millimeter as the basic unit of measurement.

You are able to label your ducts in mm rather than inches and display your diffuser air volume in LPS rather than CFM.

The only limitation is that load calculations do not work in drawings where the base unit is one mm. All other calculations work correctly, but English units are used. The result is that your ducts will still be sized to even increments, but you can display the dimension in cm's.

In order to display metric labels, you need to modify your dm_hvac-standards file. For duct labels, on round ducts, DM will be replaced with the diameter of the duct, and on rectangular and flat oval ducts, WM will be replaced with the width and DM with the depth. For diffuser labels, you need to add a new line under Other Style Information that is labeled CFM Label Format. When the diffuser label is drawn, $CFM will be replaced with the CFM of the diffuser and $LPS will be replaced with the LPS of the diffuser. For a more detailed explanation, refer to the new user guide or call Design Master for assistance.


0 Length Ducts: CFM calculations no longer crash when ducts with a length of 0 are present.

Copying Ducts and Diffusers: In certain cases, when diffusers and ducts were copied together, the connection between the new items was not properly created. The result was that ducts that appeared to be connected to diffusers were not, and CFM totals were improperly calculated. This has been fixed, so that diffusers and ducts that are copied properly maintain their connections.

Duct Calculations: The duct calculations dialog has new options. The first button will calculate the CFM and the size of ducts. The second button will calculate the CFM and pressure of ducts. The third button will calculate the CFM, size, and pressure.

This change forces a calculation of the CFM before any other calculations are run, which will prevent errors. It also allows you to easily calculate the sizes of ducts without also calculating the pressure drop. This is useful because the pressure drop calculation is time-consuming and does not need to be run as often as the duct sizing calculations.


Drawing to Drawing Connection: The drawing to drawing connection command no longer changes the case of the drawing names.

Negative Elevations: Negative ductwork elevations are now stored and displayed properly.

Vertical Connect From an Offset Duct: A macro was added that makes creating a vertical duct coming out of an offset duct easier. You select offset duct that the vertical is coming out of and the location of the vertical duct. The macro then inserts a set of transparent ducts automatically to maintain the airflow. Refer to the user manual for more detail.


Coordinate Light Fixtures with Diffusers: This function now works properly with round diffusers.

Master to Project Schedule: Copying diffusers from the master schedule to the projects schedule now works properly.

Spaces in Diffuser Callouts: Spaces are no longer removed from diffuser callouts. Spaces are still inserted before numbers to help maintain the proper ordering of diffusers.

Diffuser Editing: The Edit Diffuser command has been replaced with Query Diffuser and Edit Multiple Diffusers. The query command allows you to look at a single diffuser and make changes to it. The edit multiple allows you to make changes on more than one diffuser at a time.

Diffuser Connections

Side Connection Graphics: The graphics for side connections have been updated for slot and ceiling diffusers.

Transparent (Phantom) Diffuser Connections: The Phantom Diffuser Connection function was renamed Transparent Diffuser Connection. When you insert a transparent connection, it now inserts an extra duct so that the ducts move properly when you move the diffuser.

Top Diffuser Connection: You can now show the connection coming into the top of a diffuser as either an elbow (the only option previously available) or as a tee. This change affects 2D graphics only. The 3D graphics remain unchanged.

Diffuser Connection Offset: Perpendicular diffuser connections now come in as centered, rather than inheriting the offset setting of the duct they are being connected to.

Default Connection Type: The default connection type for bottom connections is now set independently of ceiling diffusers.

Locked Diffuser Connection Shapes: Diffuser shape for ducts connection to diffusers can automatically be locked, so you can easily implement rectangular trunk ducts and round run-outs.

2D Drafting

Lining: The width of lining is now specified and drawn correctly. A two-inch duct lining will make your duct draw four inches bigger (two on each side). You can label ducts using either their interior or exterior dimensions. The choice of using exterior or interior duct dimensions is set in the standards file. On round ducts, DE and DME will display the exterior diameter (in inches and in cm). On rectangular and flat oval ducts, WE and WME will display the exterior width and DE and DME will display the exterior depth.

Duct Labeling: You can now append a prefix or a suffix to duct labels on a per system basis. If you would like to add more information to your labels, please email us a copy of your dm_hvac-standards.txt file with a description of what prefixes or suffixes you would like included.

Dashed Ductwork: You can now more easily draw dashed ductwork. Please contact us if you would like more information on how to configure Design Master for this.

Ductwork That Does Not Hide The Background: There is an Option to draw ductwork below the background so that the hide command will no longer obscure the background.

Improved Fitting Graphics: The 2d graphics for the following fittings were improved.

Dampers: Dampers can now be moved.

Offset Vertical Ducts: This fitting now draws better in 2d.

Duct Labels: Ducts labels are now drawn above so that they are not hidden when HIDETEXT is on.

Fittings Before Transparent Ducts: A fitting is no longer automatically drawn before transparent ducts. This annoyance would often happen when drawing transparent ducts through equipment.

3D Drafting

Vertical Graphics: The vertical graphics for many situations were improved.

Branch Fitting: Rectangular branches coming out of round trunks draw correctly in 3d now. Previously, the rectangular branch was rotated 90 degrees.

Load Calculations

Saving Wall Heights: Wall heights saved using the Query Wall Command show up properly the next time you query the wall.

Load KW Display: The load KW on the load calculation dialog now lists 2 decimals places

Zone OSA Calculations: Fixed incorrect calculation of OSA CFM / person for zones.

Shared Wall Points: Rooms with walls that share a common start or end point can now be properly edited.

Break Wall: This function now divides the glass and door area evenly between the two walls, rather than giving each wall the original amount. This only applies when the area is set as an absolute number and not a percentage. If it is a percentage, both walls keep the same percentage as the original wall.

Remove Wall Node: This function now adds the glass and door area from the two walls together for the areas in the new wall. If the areas are a percentage, then an the average percentage is calculated and applied to the walls.

Wall Color: Wall colors settings are properly saved now in the wall project and master schedules.

Glass SHGC: Several releases ago the glass shading coefficient (SC) was changed to the more commonly used solar heat gain coefficient (SHGC), but the formulas were not adjusted accordingly. As you know, all values of SHGC are 87% of the SC. This release has been updated to reflect the proper definition of SHGC. Design Master was incorrectly calculating the glass load. We were using the glass Solar Heat Gain Coefficient (SHGC) as the Shading Coefficient (SC). This resulted in glass loads that were about 15% too low. SHGC is equal to SC multiplied by 0.87.

To maintain consistent load numbers between the two versious, the SHGC for all glass defined in project schedules was multiplied by 0.87. This will balance out the change we made to the glass load formula, resulting in loads that are the same.

Glass SHGC in Master Glass Schedules: Previously, the SHGC of all the master glass schedules were set to a default of 1.0. This release includes updated values for the SHGC with numbers The SHGC numbers in the master schedule will be updated to reflect better numbers based upon charts 4 and 13 of Chapter 30 in the 2001 ASHRAE Fundamentals Handbook.


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