topic Re: Problem with flow in duct accessories in Revit MEP Forum

Problem with flow in duct accessories

Anonymous — Wed, 17 May 2017 09:23:22 GMT

Hi everybody,

I've got a problem for a while with duct's accessories : I can't find a proper way to see the flow within the accessories. I have set the flow configuration to "Calculated" and an instance parameter is linked to the flow but I only see "0". My accessory is a sound attenuator and the flow direction within the connectors are set to "Bidirectionnal". (I already tried to set one connector to "Interior" and the other "Exterior" but it didn't help)

Anyone can teach me a proper way to do this ?

PS : I've already looked at the following topic "flow in duct accessories" but it seems that it doesn't work every time

Cheers,

Re: Problem with flow in duct accessories

Scott_D_ — Fri, 19 May 2017 20:49:20 GMT

I am not a big fan of Bidirectional connectors to be honest but your mileage may vary.

Your air terminals should be set to Preset, is that how they are setup?

Re: Problem with flow in duct accessories

Secttor — Sun, 21 May 2017 17:34:34 GMT

tried to set connectors on global?

Re: Problem with flow in duct accessories

Anonymous — Mon, 22 May 2017 07:18:42 GMT

Hi @Scott_D_ and @Secttor

Thank you for your replies !

Yes, my air terminals are in preset.

Here are some attached pictures where you can see that I have 2 different Fire Dampers with the same configuration.

With the accessory at the left I can see the flow perfectly and with the other I can't...

That's why I thougt that the method can differ from one accessory to the other.

Have you ever see that before ?

Re: Problem with flow in duct accessories

Anonymous — Mon, 22 May 2017 07:19:32 GMT

The last picture

Re: Problem with flow in duct accessories

Scott_D_ — Mon, 22 May 2017 08:07:17 GMT

The only difference I can see between yours and ours is that the flow direction is set to 'Bidirectional' rather than In and Out.

Perhaps your accessory is the wrong way round for it to flow correctly.

Re: Problem with flow in duct accessories

Anonymous — Mon, 22 May 2017 08:23:36 GMT

Yes but my connectors are set to "In" and "Out", I will try to solve this and get back to you if I find the solution.

Could it be due to the Classification System, "Extract" or "Supply" ?

Kind regards,

Re: Problem with flow in duct accessories

Scott_D_ — Mon, 22 May 2017 08:32:46 GMT

As long as the system classification is the same on both connectors it should work correctly.

Re: Problem with flow in duct accessories

Anonymous — Mon, 22 May 2017 10:01:28 GMT

@Scott_D_ You were right !

After searching into my whole system I discovered that the flow wasn't set correctly for one of my fitting/accessory and caused that issue.

For those who are wondering how to do this properly you have to check that all your system is well connected and the flow set correctly for every fitting accessory. Then for your accessory I recommand to set in the connector properties as following:

Flow configuration : Calculated

Flow direction : One connector must be set to "In" and the other "Out"

System Classification : "Global" or the same as your entire system if you have set it

Re: Problem with flow in duct accessories

Scott_D_ — Mon, 22 May 2017 10:06:50 GMT

I'm glad I could help.