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Modelling Exhaust Fan in DesignBuilder

Hello everyone,

In DesignBuilder I am modelling Type C ventilation, meaning that the supply air is solved by infiltration and natural ventilation (I use Air Flow Network (AFN - Calculated ventilation) for this) and the exhaust air should be solved by a mechanical fan (Detailed HVAC).

The problem arises with the "Exhaust fan" object I put in the zone. Since there is no Air Handling Unit in Type C (the one used in Type D), the Exhaust fan object should work as a separate object. However, when I run the simulation, the program throws me an error: "Zones with an exhaust fan defined in HVAC must have exactly 1 corresponding rectangular external vent from the 'Zone Exhaust Fans' category in the zone (or one of its child zones): 1F:Lounge."

link to a screenshot of the issue: https://drive.google.com/file/d/1UwWljiWzuPOg56MFJ8ojesJU0-pgSIxj/view?usp=drive_link

Screenshot of the issue

Basically the same is stated on the web: DesignBuilder - Exhaust Fans and also here: DesignBuilder - Vents

So I tried to add a grille (vent) to the perimeter wall for each room (zone) that has an exhaust fan, but the error still persists.

Could someone please advise me how to properly solve this problem with exhaust fan and vents?

Thank you.

Modelling Exhaust Fan in DesignBuilder

Hello everyone,

In DesignBuilder I am modelling Type C ventilation, meaning that the supply air is solved by infiltration and natural ventilation (I use Air Flow Network (AFN - Calculated ventilation) for this) and the exhaust air should be solved by a mechanical fan (Detailed HVAC).

The problem arises with the "Exhaust fan" object I put in the zone. Since there is no Air Handling Unit in Type C (the one used in Type D), the Exhaust fan object should work as a separate object. However, when I run the simulation, the program throws me an error: "Zones with an exhaust fan defined in HVAC must have exactly 1 corresponding rectangular external vent from the 'Zone Exhaust Fans' category in the zone (or one of its child zones): 1F:Lounge."

link to a screenshot of the issue: https://drive.google.com/file/d/1UwWljiWzuPOg56MFJ8ojesJU0-pgSIxj/view?usp=drive_link

Screenshot of the issue

Basically the same is stated on the web: DesignBuilder - Exhaust Fans and also here: DesignBuilder - Vents

So I tried to add a grille (vent) to the perimeter wall for each room (zone) that has an exhaust fan, but the error still persists.

Could someone please advise me how to properly solve this problem with exhaust fan and vents?

Thank you.