Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question

Air extraction in wet rooms

asked 2021-02-25 14:46:47 -0600

Giorgio's avatar

updated 2021-03-15 11:53:25 -0600

Hello, in many buildings with natural ventilation is present an extraction fan in bathrooms, toilets etc... which don't have external walls but only share partitions with other rooms. Is it possible to simulate this? With the fan switching on when the room is occupied? I've used the "Fan - Zone Exhaust" but is not working


edit retag flag offensive close merge delete


@Giorgio to clarify, are you trying to simulate airflow from one zone into another zone that occurs with a fan only when one zone is occupied?

Aaron Boranian's avatar Aaron Boranian  ( 2021-03-14 09:22:37 -0600 )edit

Yes basically yes, image an extractor fan in a toilet without windows and connections with external walls, the air should move from the room with the window (let's say the hall) and go into the toilet for the extraction. The schedule should follow the occupation one

Giorgio's avatar Giorgio  ( 2021-03-14 10:00:43 -0600 )edit

1 Answer

Sort by ยป oldest newest most voted

answered 2021-03-15 11:52:06 -0600

This process is usually called transfer air (air moves from one zone into another before exhausted outdoors). This post covers most of the modeling approach in DesignBuilder for transfer air.

To have the exhaust fan operate when the zone is occupied, you will need to do a few things:

  • set the System availability manager coupling mode input field to 2-Decoupled. This will allow the exhaust fan to operate independently of central system fans.
  • create a schedule with values of 1 when the zone is occupied and values of 0 for all other times, then assign that schedule name to the exhaust fan's Availability Schedule input field.
edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer


Question Tools



Asked: 2021-02-25 14:46:47 -0600

Seen: 117 times

Last updated: Mar 15 '21