topic Betreff: Calculating Air Flow in Revit MEP Forum

Calculating Air Flow

alfredo.aceves1 — Mon, 24 Apr 2023 16:11:58 GMT

Is there more than one way to calculate air flow for a building in revit? There is one way that I know of, but I am not sure if it is the only way. This method requires running systems load analysis for heating and cooling loads. In the report it gives a an airflow/area value. This value times the area of the rooms gives the airflow.

Betreff: Calculating Air Flow

iainsavage — Mon, 24 Apr 2023 20:11:50 GMT

The air flow generated by the load analysis is the volume of air required to offset the cooling load at the defined temperature difference between supply and room.

For Outdoor Air you can change the method of assigning that value in the space properties, then apply the required values:-

For overall supply rate you can apply a design rate:-

I will however admit that I don't know how those factors affect the results of the loads analysis especially in the Systems Analysis as opposed to the older Heating & Cooling Loads tool.

You can edit the

Betreff: Calculating Air Flow

alfredo.aceves1 — Mon, 24 Apr 2023 20:29:55 GMT

I was more or so focused on the airflow calculation. Specifically, I'm thinking about a program called Trane Trace. I used this for work calculate the needed airflow, however, I was hoping to do this through revit to make the process more efficient.

Betreff: Calculating Air Flow

iainsavage — Mon, 24 Apr 2023 21:38:51 GMT

Betreff: Calculating Air Flow

iainsavage — Mon, 24 Apr 2023 21:52:57 GMT

I just noticed that in the Analytical Spaces schedule the airflow is, as you say, stated as a rate per unit floor area.

To get the actual air flow value you would therefore need to add a calculated value by multiplying that factor by the floor area.

Betreff: Calculating Air Flow

alfredo.aceves1 — Mon, 24 Apr 2023 22:48:41 GMT

This works, thank you. How did you get the air flow parameter to show on the report?

Betreff: Calculating Air Flow

iainsavage — Tue, 25 Apr 2023 11:32:17 GMT

@alfredo.aceves1 schrieb:
This works, thank you. How did you get the air flow parameter to show on the report?

Select the System Load Summary tab

One problem with Systems Analysis, unless they've changed it, is that the calculated data from the Analytical Spaces does not transfer back to the model Spaces, unlike the older Heating & Cooling Loads tool.

The solution appears to be to use Dynamo to transfer the data across from Analytical spaces to model spaces.

https://forums.autodesk.com/t5/revit-mep-forum/model-spaces-not-updated-from-analytical-spaces/m-p/11235080

https://forums.autodesk.com/t5/revit-mep-forum/heat-and-cooling-load-in-revit-2022/m-p/10296247#M78618