hvac in autocad® mep: new and improved david butts...

HVAC in AutoCAD® MEP: New and Improved

David Butts – Gannett Fleming

MP3724-L

In the Building Information Modeling (BIM) world, there are still many users who have AutoCAD MEP but

aren't ready to make the move to Autodesk® Revit® for a variety of reasons. This hands-on lab focuses

on the HVAC side of AutoCAD MEP, and will include a review of new features for duct layout, sizing duct

systems, creating quick parametric parts, and leveraging the spaces and zones for analytical models.

This lab will help you get more out of your AutoCAD MEP model—and take even more steps toward the

BIM environment!

Learning Objectives

At the end of this class, you will be able to:

• Leverage spaces and zones for gbXML export, working with external applications such as Trane Trace™

• Describe new layout features, such as reducing elbows and transitions

• Describe duct sizing methods, engineering units, and best practices

• Create content as parametric multi-view parts

About the Speaker

David is an energetic, highly motivated BIM specialist with Gannett Fleming, a large engineering and

architectural firm based in Camp Hill, Pennsylvania. His Autodesk® product expertise extends to Revit®

MEP, AutoCAD® MEP, Revit Architecture, AutoCAD Architecture, Navisworks®, Green Building Studio®,

Plant 3D and more. David's responsibilities include managing the implementation of BIM for the

engineering aspects of the firm, providing training, customization, and programming for the Autodesk

MEP product lines. He also works as BIM manager for several projects (including water and wastewater

treatment, transit, and pharmaceutical), and has also worked as a project manager for Autodesk-related

specialty projects. Prior to joining Gannett Fleming, David worked in the Autodesk reseller channel as a

training manager and applications engineer for the Autodesk building design and construction product

line. He is based in the firm's Raleigh, North Carolina office and has been speaking at AU for many years.

Email: [email protected]


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Introduction

AutoCAD MEP is the long-running AutoCAD-based engineering design and drafting solution for

mechanical, electrical and plumbing projects. Based on AutoCAD Architecture 2012, this object-oriented

software can dramatically improve coordination while helping to improve the construction document

process. In this lab, we’re going to focus on the HVAC features. We’ll cover some tools that have been in

the program for a while – and we’ll also look at new and improved tools to help you create a more

accurate model.

So let’s get started – and get the most from your AutoCAD MEP!

Leveraging Spaces and Zones

When you’re using AutoCAD MEP, It pays to define spaces and zones, These objects do more than just

help place room name tags on the drawings. Spaces are analytical areas, storing information about the

size, volume, space type, conditions and more. They can be defined by a polyline, or bound by walls.

When AutoCAD Architecture objects for walls, doors and windows are used, the space automatically

recognizes and links to these objects – so if they are changed, added or removed, the space will track

them.

Spaces are attached to Zones, which track the total amount of area and volume of the group, and adds

analytical data that can be used to determine the heating and cooling loads in the building. Zones can

also be attached to other zones, and can be graphically represented on plans.

Let’s take a look at how we can add spaces to a model, associate them with a zone, and then edit their

data.

1. In the class dataset folder, open the AU 2011 MEP Base.dwg file.

2. Start by adding spaces to the model – from the Home tab, select the Space tool:


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3. Check the properties palette – make sure the Create Type option is set to generate.

4. Check additional settings for the space height, type, and more:


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5. Read the command line – use the General all option to automatically place spaces in all enclosed

areas of the model:

6. Note – spaces will not be created in enclosed areas if a space is already defined. Press Enter to

complete the command.

7. Once the spaces are placed, select one of the spaces. Review the properties – let’s name this

particular space Lobby:


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8. Change to the Extended Data tab on the properties palette. Scroll down to the property sets area.

Set the space type to Lobby, and the condition type to Heated and Cooled:

9. Go back to the Design tab – select the Space Zone Manager:

10. Since the lobby was selected, it properties show up automatically in the dialog. The right panel

shows general information, contents, calculation types and modifier styles:


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11. At the bottom of the dialog, check the boxes to

spaces, and to show space surfaces

12. Expand the lobby. Scroll through and note all of the openings in the walls

currently grayed out because the space is

space will be updated:


At the bottom of the dialog, check the boxes to show all zones and

show space surfaces:

Scroll through and note all of the openings in the walls – their properties are

currently grayed out because the space is associative. If the door, window or wall is cha

their properties are

. If the door, window or wall is changed, the


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13. Select OK to exit the space/zone manager. Use the view cube to change to a 3D point of view:

14. While the lobby is still selected,

the drawing.

15. Select OK to exit the space zone manager.

16. From the Analyze tab, select the


elect OK to exit the space/zone manager. Use the view cube to change to a 3D point of view:

While the lobby is still selected, go back to the space zone manager. Note how it’s highlighted in

to exit the space zone manager. Use the view cube to return to the Top

tab, select the Zone tool:

elect OK to exit the space/zone manager. Use the view cube to change to a 3D point of view:

ote how it’s highlighted in

Top view.


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17. Place a zone outside of the building as shown:

18. Pick the zone – a plus sign grip will appear. Pick it, then pick the spaces as shown below:

19. Next, go to the properties dialog while the zone is still selected. Under Properties, name the zone

1st

North.


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20. Review the dimensional properties of the zone:

21. You can also add and remove spaces as needed for the zone. The zone is a required object –

you can’t perform an energy analysis without at least one zone in the model.

22. Take a few minutes, and edit the properties of the spaces. Set the space type offices around the

perimeter (note – you can select more than one space at a time, and edit the properties as

needed). Save your model before you start the next section/

Once zones are defined, you export to a gbXML, which can be imported into analysis applications such

as Trane Trace, IES Virtual Environment and Ecotect Analysis.

If you’ve gotten behind, open the AU 2011 – MEP Base – Export gbXML.dwg file to continue.

23. To export the space and zone data, go to the Analyze tab – select the Export gbXML tool:


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24. This dialog lets you:

• Define where you want the exported gbXML file to be located;

• select Zones to export;

• Set the building type and zip code;

• Start and monitor the progress of the export;

• And show where errors may have occurred

The icons on the right side allow you to highlight the selected object, and fix the

one occur.


Define where you want the exported gbXML file to be located;

select Zones to export;

Set the building type and zip code;

Start and monitor the progress of the export;

And show where errors may have occurred – if an error occurs, a message will appear:

The icons on the right side allow you to highlight the selected object, and fix the

if an error occurs, a message will appear:

The icons on the right side allow you to highlight the selected object, and fix the error, should


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After the export is complete, you can now open the file with notepad, review the output, and import into

your analysis application. By using spaces and zones, you save a tremendous amount of input time over

traditional methods.

Duct Layout – New and Improved

AutoCAD MEP 2012 includes lots of improvements to make duct layout easier and more fun. In this class,

we’re going to work on these tasks, since they’re either a new tool or in a new location, to make it easier

to:

- Creating a vertical riser - Creating a sloped duct - Define Routing solutions - Add Offset Transitions

We’ll start with the drawing, AU 2011 MEP Base – Duct Layout.

1. Zoom to the north side of the building:

2. Start by drawing a duct from the VAV – pick it, and then use the grip to add the duct. Add the

main as shown:

3. To connect the duct to the main, pick an air terminal – use the plus sign grip to start the duct. On

the properties palette, change the elevation to 11’ 6”. Under the advanced section, check the

branch fitting – make sure it’s set to use a Takeoff for the connection – this is a new location for

this feature:


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4. Pick the main duct – look for the duct connector snap, and make the connection to the main –

choose Accept when prompted.

5. Notice how the takeoff is added – the fitting types are controlled by the duct routing preference.


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Here’s another point – AutoCAD MEP added a vertical riser on its own, based on a Duct preference setting. To see how this works, go to the Manage tab, and pick the tool:

Duct preferences include settings to make adding duct easier. The first one we’re looelevation changes feature, which has been in the program for a while. By having this checked, you simply have to type in the new elevation, and the vertical riser is added. The second is a new feature, the the duct routing preferences to use a reducing elbow first, if the size changes. The second adds a non-reducing elbow, and places a reducer directly on the fitting to make the size adjustment:


AutoCAD MEP added a vertical riser on its own, based on a Duct preference setting. To see how this works, go to the Manage tab, and pick the Duct preferences

Duct preferences include settings to make adding duct easier. The first one we’re loofeature, which has been in the program for a while. By having this checked,

you simply have to type in the new elevation, and the vertical riser is added.

The second is a new feature, the Elbow layout options. You get two options here the duct routing preferences to use a reducing elbow first, if the size changes. The second adds a

reducing elbow, and places a reducer directly on the fitting to make the size adjustment:

AutoCAD MEP added a vertical riser on its own, based on a Duct Duct preferences

Duct preferences include settings to make adding duct easier. The first one we’re looking at is the feature, which has been in the program for a while. By having this checked,

options here – the first forces the duct routing preferences to use a reducing elbow first, if the size changes. The second adds a

reducing elbow, and places a reducer directly on the fitting to make the size adjustment:


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When creating a vertical riser, there are a couple of rules:

• There has to be enough elevation change for the fittings to fit, so consider using different

elbow types, such as mitered instead of long radius;

• You have to have the automatic create riser turned ON under duct preferences.

Let’s look at how this works.

1. Start by picking the VAV box in the north corridor. Select the plus sign grip to start adding a duct:

2. Immediately go to properties – check the duct preferences first under routing options:


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3. Make sure the automatic riser option is checked. Select OK to close the dialog.

4. Draw a short section of duct – based on the elevation of the VAV box, the duct should be at 12’

3”. From the properties dialog, set the elevation to 10’ – the vertical drop will appear once you

press enter:

5. Go ahead and pick a second point – this duct will be centered at 9’-9”, since that the amount of

room that’s available. Regardless of what elevation you picked – it’s got to have enough room to

place the fittings, so it forces the lower elevation.

6. Next, go back to duct preferences and turn off the automatic riser. To add a sloped duct, start a

new duct run with the plus sign grip from the last duct segment.

7. On the properties palette, change the elevation to 11’.

8. Notice the riser doesn’t appear, so pick a second point – a sloped duct will be added up to this

elevation, so give yourself a little room – you may get a warning about custom layouts, so pick

Yes to continue:


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9. The next point you select will place a duct at 11’, running flat – so you can use this method to rout

duct around other items, and avoid conflicts:

10. Here’s a section view of the results – you can see this by selecting the south face of the view

cube:

From this view, you can select grips on the low duct, and drag it up to a different elevation if

needed.

11. Let’s take a look at another way to add the sloped duct – delete the sloped duct and fittings you

just added, from the section view (select it, and press the Delete key):


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12. Pick the low duct, and then pick the plus sign grip – draw a duct to the end of the higher duct:

13. Use the duct end connector to snap to the end of the higher duct.

14. You’ll get a number of routing solutions – type in N and press enter to cycle through the options.

When you get the 45’s, type in A for accept, and press enter:

Again – as long as you have room to make the fittings, it will create the run.

Let’s see how the elbow layout options work.

1. Change back to a plan view, and select the last duct segment – pick the plus sign grip to start

drawing another duct:


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2. On the properties palette, go to

elbow is set:

3. Select OK to exit the preferences dialog. Stay on properties, and go change the diameter

4. Pull your mouse straight down to place the elbow

Round Duct Reducing Elbow


palette, go to preferences – make sure the layout option for using a

to exit the preferences dialog. Stay on properties, and go change the diameter

Pull your mouse straight down to place the elbow – you’ll get the Choose a Part

Round Duct Reducing Elbow:

make sure the layout option for using a reducing

to exit the preferences dialog. Stay on properties, and go change the diameter to 12”:

Choose a Part dialog. Select the


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5. Select OK – and the reducing elbow is placed. This works with all shapes and sizes of duct in

AutoCAD MEP 2012.

Another way to connect duct that isn’t aligned is to use the new offset transition feature. This places a

single fitting that can also transition between different sizes and shapes.

1. For the offset transition, return to the top view. Zoom to the west corridor, and locate the two

disconnected ducts:

2. From the Home tab, select the duct fitting flyout – pick the duct transition utility:

3. Pick the two ends of the duct – the program will add the transition, based on the duct routing

preference settings:


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Note: if you don’t get a transition, go to the Manage tab – under the style manager, select HVAC

Duct Routing Preferences:

4. Select Standard – then check the fitting settings on preferences. Make sure you have a fitting

selecting for any part that lists offset. You’ll need to do this if you started the drawing in an earlier

release, or didn’t have this set for your template.


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These are just a few of the ways to create custom layouts – so you need to practice!

And if you make a mistake, don’t forget one of my other favorite commands – UNDO!

Duct Sizing Methods

A new feature for this release of AutoCAD MEP relates a drawing’s duct engineering units. The Drawing

Setup dialog, which normally controls items such as layering standards, units, scale and object display,

includes a tab for HVAC.

You can access this tool by using the application menu – pick drawing utilities, and then drawing setup.

Pick the HVAC tab.

1. There are three items you can now control.

The first is air flow units. From here, you have several options –

• Cubic feet per second

• Cubic feet per minute

• Gallons us per second

• Gallons us per minute

• And Gallons us per hour

These are a measurement of air flowing through a duct system.

2. Friction units measure in two forms –

• Inches of water per 100 feet

• Inches of mercury per 100 feet


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These options are part of a loss factor calculation, for friction loss in a duct.

3. Velocity units set three options:

• Feet per second

• Feet per minute

• Miles per hour

This sets the units of measurement for airflow in the duct.

Each of these settings help the user that is leveraging the duct sizing tools to control the calculation

method. The settings should be made in your MEP template, that is used to create your constructs or

base plans, but can be adjusted as needed once the drawing is created. When a project is being

completed in metric, then default metric values would be listed as the options.

A few extra tips for sizing duct –

1. Make sure that all ducts are connected – use the solution tips setting located on the view tab.

Make sure this is turned on:

When a duct isn’t properly connected, you’ll see the tip:


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Duct can’t be properly sized with open connections, so solve these before sizing duct.

2. Make sure that all end of line components have

then right click. Pick the MvPart Modify

dialog:

If flow is set to 0, then the duct can’t be sized.

room.


properly sized with open connections, so solve these before sizing duct.

Make sure that all end of line components have airflow set – for air terminals, select one, and

MvPart Modify tool on the pop-up menu, and select the

If flow is set to 0, then the duct can’t be sized. Change this value to the correct flow rate for the

properly sized with open connections, so solve these before sizing duct.

for air terminals, select one, and

up menu, and select the flow tab on the

Change this value to the correct flow rate for the


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3. Another tip is to check the flow direction – go back to the view tab, and turn on the Show Flow

feature:

The flow arrows will appear on the duct – to change the flow direction, pick the duct. Right click

and pick the reverse segment tool:

This will correct the flow direction.


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4. Finally, you can export the duct systems out to external applications, such as Trane’s Variduct

design tool. To do this, go to the

5. From the dialog, set the location

VAV box in the north corridor. Once it’s selected, you can set the

start.

6. The dialog monitors the progress, and you can view the event log for errors

as the gbXML export feature.

After using the external application to size the duct, you can re

system will be adjusted as sized.


Finally, you can export the duct systems out to external applications, such as Trane’s Variduct

design tool. To do this, go to the Analyze tab. Pick the export ductXML tool:

location of the exported XML file. Next, use select object

VAV box in the north corridor. Once it’s selected, you can set the system type, and then press

The dialog monitors the progress, and you can view the event log for errors – the same behavior

as the gbXML export feature.

After using the external application to size the duct, you can re-import the settings, and the duct

Finally, you can export the duct systems out to external applications, such as Trane’s Variduct

select object, and pick the

, and then press

the same behavior

import the settings, and the duct in the


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Creating Parametric Multi-

For our last section, the Parametric Part Wizard

improvements and more parts. Making parts in AutoCAD MEP with the Content Buil

cumbersome – and sometimes, you just need to make a quick fitting or part. AutoCAD MEP includes

tool, which leverages the power of parameters and part templates to help you create a part

take a look at how this works, and mak

1. Start the utility from the Home

.

The Wizard creates and stores the parts in your default catalogs, so you can move them around

to your own custom catalogs, or leave them

default first, and then move them so I don’t have to worry about updates.


-view Parts

Parametric Part Wizard has been in a few releases – it continues to get

Making parts in AutoCAD MEP with the Content Builder can be

and sometimes, you just need to make a quick fitting or part. AutoCAD MEP includes

which leverages the power of parameters and part templates to help you create a part

, and make a new air terminal.

Home tab – pick Tools, and then pick the Parametric Part Wizard


to your own custom catalogs, or leave them in the default locations – but I’ll make mine in the

default first, and then move them so I don’t have to worry about updates.

continues to get

der can be

and sometimes, you just need to make a quick fitting or part. AutoCAD MEP includes this

which leverages the power of parameters and part templates to help you create a part – fast. Let’s

Parametric Part Wizard:


but I’ll make mine in the


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2. From the dialog, start by checking the part domain – you can create duct, multi-view part and pipe

components:

3. Select Duct – from here, you can add transitions, crosses, elbows, takeoffs and tees.

4. Select Pipe – from here, you can add connectors, couplings, crosses, transitions, elbows, tees

and wyes.


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5. Select Multi-view parts – from here you can add air terminals, air handling units, VAV boxes,

pumps, valves, fans, boilers, chillers, tanks, water heaters, cooling towers, and heat pumps.


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6. Select the Air Terminal – for the part template, select the

7. Type in Round Neck Air Terminal

the part.

8. For the D1 duct connector values, add

9. For the H Height values, add

10. For the L and W values, add

Since these are parameters, you only have

the sizes and versions for you.

11. Select OK – and the add multi


for the part template, select the Round Neck template.

Round Neck Air Terminal for the name and description. These are required to create

duct connector values, add 6”, 8”, 10” and 12”.

Height values, add 6” and 8”.

values, add 24” for each.

Since these are parameters, you only have to enter the data once – the wizard will create all of

the sizes and versions for you.

ulti-view part dialog will open:

.

for the name and description. These are required to create

the wizard will create all of


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12. The part is added to your m

defined!

And that’s all there is to it – so if you want to create simple parts, use the parametric part wizard to make

them and add them to that catalog –

Conclusion

AutoCAD MEP 2012 is even more powerful than before,

Being based on AutoCAD means that you don’t have to move to Revit until you’re ready, so take

advantage of the sweet features and get more out of your models!

For a side note, you can learn more about AutoCA

CADLearning site. I was lucky enough to be selected to author this year’s edition, and produced over

150 beginner, intermediate and advanced

www.cadlearning.com today.

Have a great AU 2011 – David B.


The part is added to your multi-view part catalog already – and 8 different diffusers are already

so if you want to create simple parts, use the parametric part wizard to make

– so you can use them in any drawing or project.

AutoCAD MEP 2012 is even more powerful than before, and can keep up with any other BIM application.


advantage of the sweet features and get more out of your models!

For a side note, you can learn more about AutoCAD MEP 2012 by visiting 4D Technologies

site. I was lucky enough to be selected to author this year’s edition, and produced over

beginner, intermediate and advanced training videos for this application. For more information, visit

t diffusers are already

so if you want to create simple parts, use the parametric part wizard to make

and can keep up with any other BIM application.


4D Technologies’

site. I was lucky enough to be selected to author this year’s edition, and produced over

training videos for this application. For more information, visit

hvac in autocad® mep: new and improved david butts...

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