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Distinguished Contributor
thewrz
Posts: 171
Registered: ‎06-08-2009
Message 11 of 17 (515 Views)

Re: Duct Fitting & ASHRAE Table

01-19-2012 02:24 PM in reply to: CM-Black

Thanks so much Martin!

 

I think I'll consult some of the Mech engineers in my office about how loss is dealt with in tees. 

 

I have a lot to learn about HVAC design (I design primarily electrical systems), but I want to see if I can do darned near everything inside the box (the box that is Revit MEP). Once I get a better understanding I'll see if I can talk more intelligently about making sure loss is taken into account for Tees (To me Tees seem like funky right angle elbows). 

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Please give kudos to the MEP Wish List ideas you like, as this will help the Revit development team prioritize functionality additions!
New Member
mike.fowler
Posts: 1
Registered: ‎02-07-2013
Message 12 of 17 (414 Views)

Re: Duct Fitting & ASHRAE Table

02-07-2013 01:34 PM in reply to: martin.schmid

I was unable to get the plugin to load on startup.  I am using Revit 2013.  Please see the atttached image and let me know if you have any ideas....

Employee
martin.schmid
Posts: 1,297
Registered: ‎11-16-2005
Message 13 of 17 (397 Views)

Re: Duct Fitting & ASHRAE Table

02-07-2013 11:45 PM in reply to: mike.fowler

Hi Mike-

 

In some cases this issue is due to Windows security.  See:

http://blogs.msdn.com/b/brada/archive/2009/12/11/visual-studio-project-sample-loading-error-assembly...

 

The short answer may be to:

1.  browse to where the .dll file is

2. right click the .dll file

3. select Properties

4. Select the General tab

5. Near the bottom, you may see: "Security:  This file came from another computer and might be blocked to help protect this computer".  Next to that is an 'Unblock' button.  Click that.

 

Then, try to re-launch Revit.  This solves the problem in some cases.

 

Cheers-

MS



Martin Schmid, P.E.
Product Manager - Revit MEP
Architecture, Engineering, and Construction
Autodesk, Inc.

Active Contributor
msoren
Posts: 46
Registered: ‎12-10-2007
Message 14 of 17 (284 Views)

Re: Duct Fitting & ASHRAE Table

10-02-2013 09:28 AM in reply to: CM-Black
I know this is an old post however, In Revit 2014 it appears that the duct fitting tables for flat oval duct have not been incorporated as the other fittings hav been. tables sf4-1 through sf4-8 were not included in previous releases as well though oddly sf5 tables were. Strange that you would include some of the flat oval but not all of it. our firm primarily uses flat oval duct for our high pressure system without entering in the Coefficient for each of these fittings individually how could I get around this.
Distinguished Contributor
thewrz
Posts: 171
Registered: ‎06-08-2009
Message 15 of 17 (277 Views)

Re: Duct Fitting & ASHRAE Table

10-02-2013 10:22 AM in reply to: msoren

Read my EDIT below...l

 

Rather than trying to mess with ASHRAE tables and other weird Revit voodoo --- I think you’ll be better off creating a schedule that groups up all your fittings by elbow, transition, etc (turn OFF itemize each instance), and then assigning them all the same loss value (be conservative, obviously).

This will speed up your calcs, give you a very good estimate (albeit on the conservative side), and allow you to get the project done quickly. Don’t get to detailed on each individual elbow or fitting’s loss value. Unless you’re a contractor building shop drawings, you don’t need that level of accuracy (our take-offs in our firm are quite conservative, which allows for more flexible field adjustments without upsizing the fan or equipment... which can be VERY costly).

 

EDIT: I should point out you should only do this after you are SURE your duct systems correctly have a flow direction. If you're just randomly drawing ducts, hoping to get ASHRAE tables asigned, you'll be dissapointed. There has to be a fully complete and connected system BEFORE all the tables get worked out.

 

Here is a link to one of the projects I created in 2013 called "No Warnings! Hurray!" --- please don't judge the quality of design, it is just an example of a project without warnings:

https://dl.dropboxusercontent.com/u/22838635/revit/No%20Warnings%20Hurray%21-rev2_2013-10-2_10.31.21...

 

 

You'll notice I've manually assigned the duct take offs a specific loss. There was no ASHRAE table for it even after the system was completed. But you'll see the elbows DO have ASHRAE tables.

 

ALSO! This is not a flat oval duct design.

____________________________________________________
Please give kudos to the MEP Wish List ideas you like, as this will help the Revit development team prioritize functionality additions!
Distinguished Contributor
thewrz
Posts: 171
Registered: ‎06-08-2009
Message 16 of 17 (266 Views)

Re: Duct Fitting & ASHRAE Table

10-02-2013 11:04 AM in reply to: thewrz
ALSO! For fun I upgraded this 2013 project to 2014. Then I changed a couple lengths of duct to Oval (using the Change Type tool after a run of ducts and elbows is selected) and it worked perfectly. It pulled up ASHRAE tables for the oval duct elbows.
____________________________________________________
Please give kudos to the MEP Wish List ideas you like, as this will help the Revit development team prioritize functionality additions!
Active Contributor
msoren
Posts: 46
Registered: ‎12-10-2007
Message 17 of 17 (258 Views)

Re: Duct Fitting & ASHRAE Table

10-02-2013 01:59 PM in reply to: thewrz
Thanks for your help.

Everything is connected with appropriate flow direction still no ashrae table. I tried changing the duct/fitting through the change type function still didn't popluate the table.

I like your idea of using a schedule to input the loss coefficient however I do not see in your example where you would have inputted it and I cannot find that parameter availiable in the schedule fields. It appears to be a system property that duct fittings are not assigned to.
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