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How do you setup pressure control in DesignBuilder?

asked 2020-03-03 04:50:54 -0500

anonymous user


updated 2020-03-25 13:12:55 -0500

I wish to investigate the leakage through walls in a single zone due to pressure difference in DesignBuilder. Is it possible to setup pressure control for a generic air loop in a detailed HVAC setup in DesignBuilder?

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answered 2020-03-03 09:58:39 -0500

Yes, you can apply the calculated natural ventilation option instead of the scheduled natural ventilation option in DesignBuilder. You can read more on natural ventilation modeling in DesignBuilder's help manual or also watch a tutorial video on this topic.

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I have the calculated natural ventilation option enabled currently. The issue is that the air-loop does not result in an amount of air 'staying' in the room, i.e. the air-loop is balanced. I wish to create a positive internal pressure by increasing the supply flow while decreasing the extract flow. I am not sure how to do this part as exhaust fans can be prescribed but they result in negative pressures.

anonymous userAnonymous ( 2020-03-03 10:06:07 -0500 )edit

Ahh, thank you for clarifying. Have you already looked at outputs for air node mass flows and airflow network node pressures to confirm that the zone is balanced and not pressurized?

Aaron Boranian's avatar Aaron Boranian  ( 2020-03-03 10:24:01 -0500 )edit

I have yes. The Mechanical ACH corresponds to the outdoor air requirement set at the HVAC zone. I also used EMS to get output for AFN Node pressure difference which was 0 Pa for all the surfaces. The mass flow across the nodes (from 1 to 2 and 2 to 1) was also 0. The splitter outlet mass flow was equal to the mixer inlet mass flow.

I used actuators to remove leakage due to wind and stack effect (reason for 0 Pa pressure difference and how I can determine if positive pressure is created from HVAC).

anonymous userAnonymous ( 2020-03-03 10:32:38 -0500 )edit

Hello @ES Meyer, Maybe, did you realize how to create positive pressure in a zone/building? I want to do this in DesignBuilder too.

paulcaicedo's avatar paulcaicedo  ( 2021-06-09 10:04:49 -0500 )edit

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Asked: 2020-03-03 04:50:54 -0500

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Last updated: Mar 03 '20