Flow won't show in the System Inspector

[tikos.mate]

Hello!

I've checked the forum about the problem, bust sadly I didn't find anything.

I have multiple AHU's in different location. The exhaust air system is common, all flow is set to the correct in the duct branching. For design the AHU, I want to check the duct systems Pressure loss, the system are well connected, I can inspect the system, but the AHU is not in the model. I closed all duct ending in the engineering rooms, and set additional flows, only one point is opend. When I select a duct, I can see the flow, and all the mechanical information. When I did the Pressure loss report, two brnaching had a flow rate 0, but a huge pressure drop. When I inspect the system, the two system shows 0 flow rate. All the directions are fine, the two prolematic system is connected, by tap. I attached a few pictures, hope it will help. When I Ispect, the lower level ducts have a blue arrowed inspect, and the upper (from AHU2) have red arrowed.

What can be the problem?

[iainsavage]

The red arrows should signify your index run.

I don't see any air terminals?

I don't follow the logic of the system with the various AHUs connected to one system.

It would be better to upload your model if you can, the screenshots don't say enough without being able to interrogate the model.

[tikos.mate]

The arrows meaning the connectoins tu the AHU. There is no air terminals, because the air came from the AHU. So I got an end cap all the connections, and I set Additional flow, like there is the AHU in the end. All the exhaust air leave the building in one place, because we didn't have more.

I copied the system to a file, I attach it.

I just opend a Default Mechanical template. The strange is, when I checked in that model the Ispector, it works properly. 

[robert.klempau · Accepted solution]

Hello @tikos.mate,

the Model you attached looks fine to me.

It nicely shows the flow.

disconnect some fittings at the point where the flow gets 0.

Then inspect the situation there.

Do you experiencing the same issue when opening the Model.rvt that you attached?

[tikos.mate]

Thank you for the replies! In the model it worked properly, I just deleted some fittings, and reconnect, and it worked perfectly. It was strange that not all fitting change solved the problem.

[iainsavage]

I'm glad you got it sorted.

Regarding your question about red and blue arrows and the comment "The arrows meaning the connectoins tu the AHU", in your image below the red arrows signify the index run (path of greatest pressure drop).

[iainsavage]

The chain of little arrows on the ducts I mean, not the big red arrow that’s been added to the screenshot!