Revit MEP

New Member
Posts: 1
Registered: ‎07-25-2011
Message 11 of 14 (392 Views)

Re: ASHRAE TABLES inside revit!!! How can I use them?

07-12-2012 10:35 AM in reply to: ruidavid



I'm French and here we do not use many methods Ashrae.


I have a question about the coefficients K.


I need to do a family that has a valve with two reducer in the same family.


So I have 3 coefficients K.  I can do, addition them?


I feel that your factor K  ​​are the equivalent of our coefficients Z (zeta) but I'm not sure. And we can do addition with coefficients Z.


Thank you for your answers.

New Member
Posts: 2
Registered: ‎07-07-2014
Message 12 of 14 (91 Views)

Re: ASHRAE TABLES inside revit!!! How can I use them?

07-31-2014 11:01 PM in reply to: luchamel2047

Iam working pressure drop calculation in 2015 version, its good & i am getting almost the same as manual one.

please look into the fittings family and the values which is giving. 


Eg: for duct elbow u have soo many option like with/wihout vanes. so use the same(SR3-3) one as u r using in manual (SR3-3)calculation.

Active Member
Posts: 9
Registered: ‎08-16-2007
Message 13 of 14 (60 Views)

Re: ASHRAE TABLES inside revit!!! How can I use them?

08-07-2014 06:41 AM in reply to: ruidavid

Some of my duct fittings have no pressure loss value. When I try to check to see which ASHRAE table it is using, the table choices are blank. On the same System, I have the exact same fitting (different size) and it works fine. What can cause this and how can I correct it?

On this same System, the CFMs are totaling up from the Air Terminals to the Mechanical Equipment. However, some of the ducts are not tallying the CFM and are thus not calculating a pressure loss.

Valued Mentor
Posts: 458
Registered: ‎06-16-2010
Message 14 of 14 (37 Views)

Re: ASHRAE TABLES inside revit!!! How can I use them?

08-12-2014 02:57 AM in reply to: sthedens

The tables have set sizes they work for. If the size of the fitting is outside the range of the table then you don't get a pressure loss. Therefore you need to either chang ethe fitting type or interpolate the value and manually add it into the properties. 

Alternatively you could edit the xml file for the Ashrae fittings but that could cause you problems if you enter the information wrong.

If my reply answers your query, please use the Accept as Solution.
Please give Kudos as appropriate to enhance the value of these forums.

Thank you!
Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.
Need installation help?

Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.