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Where could we find Controller:MechanicalVentilation in OS?

asked 2015-03-18 13:24:47 -0500

updated 2017-05-17 12:43:13 -0500

Dear All,

I am trying to close outdoor air during unoccupied mode by defining availability schedule of Controller:MechanicalVentilation. I can successfully do it in EnergyPlus, but I cannot find the controller:MechanicalVentilation in OpenStudio. Is there anybody know where the controller is located in OpenStudio? (I am using version1.5) . Thanks.

Best wishes,


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answered 2015-03-18 15:10:36 -0500

ControllerMechanicalVentilation is associated with the ControllerOutdoorAir object in OpenStudio, but we don't explicitly show all of the ControllerMechanicalVentilation fields in the Application's inspector. Its features are available though. In this case you actually want to set the Minimum Outdoor Air Schedule on the ControllerOutdoorAir as shown in the attached screenshot. This does require version 1.6 though. Prior to 1.6 we recommended setting the Maximum Fraction of Outdoor Air Schedule, but we discovered that does not work reliably.

image description

On a related note, another common use case for ControllerMechanicalVentilation is demand controlled ventilation. This is exposed in OpenStudio from the control tab.

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I was doing this just a few hours ago in the above manner. Documentation for "Minimum Outdoor Air Schedule Name" (scroll down a ways) here

keb gravatar image keb  ( 2015-03-18 15:49:11 -0500 )edit

Thanks for your response. Actually I did try Minimum/Maximum Fraction of Outdoor Air Schedule and found it did not work. Therefore, I transferred to EnergyPlus and found the availability schedule of Controller:MechanicalVentilation could close the outdoor air at night. That's why I would like to find the availability schedule in OpenStudio as well. However, like you said, if OpenStudio 1.6 could set up Minimum Outdoor Air Schedule correctly, that would be great! Thanks very much for your information!

Yan gravatar image Yan  ( 2015-03-18 15:52:08 -0500 )edit

@Kent Beason, Thanks! So have you verified that the "Minimum Outdoor Air Schedule Name" of OpenStudio1.6 does work?

Yan gravatar image Yan  ( 2015-03-18 15:57:14 -0500 )edit

OK. Let me fully disclose. The reason you need 1.6 is because we made a change so that when you set the Minimum Outdoor Air Schedule on the ControllerOutdoorAir, OpenStudio also mirrors this schedule as the ControllerMechanicalVentilation availability schedule when it makes the idf. So if you schedule the min oa schedule to anything other than 1, it has the effect of turning off the mechanical ventilation controller which was interfering with things prior to 1.6. If you really want to see the details of the change ....

Kyle Benne gravatar image Kyle Benne  ( 2015-03-18 16:10:50 -0500 )edit

here they are

Kyle Benne gravatar image Kyle Benne  ( 2015-03-18 16:11:06 -0500 )edit

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Asked: 2015-03-18 13:24:47 -0500

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Last updated: Mar 18 '15