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Is there a way of modeling fixed outdoor air fraction for VAV systems in CBECC-Com?

asked 2015-06-05 08:08:52 -0600

My hunch is that this is only possible through the Exceptional Design Compliance process, but I just wanted to see if there was a way of doing this within CBECC-Com.

I'm looking to model fixed outdoor air fraction for a system that varies supply airflow (the design OA is greater than the minimum required). My assumption is that CBECC-Com defaults to providing the design outdoor air at all times regardless of the supply airflow rate.

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I'm going to try to use the Scheduled option for the Outside Air Control Schedule Method input and set the min fraction sch to be the outdoor air fraction.

anchapin gravatar image anchapin  ( 2015-06-05 08:24:07 -0600 )edit

After adding the min fraction schedule, I found out that this Outside Air Control Schedule Method is not allowed for compliance analysis simulations.

anchapin gravatar image anchapin  ( 2015-06-05 12:59:07 -0600 )edit

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answered 2015-06-05 12:59:37 -0600

This appears to not be an allowed input for compliance analysis.

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Yes, you are correct, CBECC does not currently support modeling fixed OA fraction systems. If you feel that this capability is important, I recommend submitting an 'Other' issue and specify it as a feature request: This will allow us to formally track it as a possible feature for future versions.

DavidReddy gravatar image DavidReddy  ( 2015-06-05 19:08:49 -0600 )edit

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Asked: 2015-06-05 08:08:52 -0600

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Last updated: Jun 05 '15