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Night ventilation not working

asked 2021-03-26 14:52:28 -0500

Martinsquare gravatar image

updated 2021-03-26 16:55:29 -0500

I am trying to implement night ventilation into my energyplus model, but it is not working (no change in air temperatures and energy use, etc.) What I did: image description -In which NightventAvail is a EMS adjusted schedule. The output is 1 during nights in the summer months. Other periods it is 0 (checked the output via output:variables) -In which Officemedium HVACOperationSchd is the HVAC schedule. I used the same schedule as was used in the box of 'Fan Schedule Name' in AvailabilityManager:NightCycle. -In which NightventTemp is an EMS adjusted schedule, which varies between 19.75 and 22.75°C depending on outside conditions (checked the output via output:variables).

The problem is that it is not working. I also tried to assign it in the AvailabilityManager:assignmentList like this:

image description

What I also tried was switch the Applicability Schedule Name to an always on schedule, and switch the NightventTemp to a normal schedule value without the use of EMS. All of this didn't work.

I hope one of you knows what I am doing wrong.

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answered 2021-03-28 16:03:02 -0500

I don't think this gives enough information to understand why the simulation is not working, so I'll respond with some generic comments:

Have you reviewed the output to confirm that the fan turns on when needed? and is controlling to the proper setpoint? with full outdoor air?

Normally you can "reverse engineer" the input problem by noting which part of the operation is not doing as you expect.

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Thank you for you reaction. I reviewed if all conditions for nightventilation are met.

  • tempertaure difference between in and outside >2°C
  • Inside temperature above specified 'Ventilation Temperature Schedule'
  • Applicability schedule = 1
  • Inside temperture above lower limit

However, the fan's flow rate is 0 kg/s

Martinsquare gravatar image Martinsquare  ( 2021-03-29 06:59:43 -0500 )edit

If you're willing to send the IDF, I'm willing to take a closer look.... (

Jim Dirkes gravatar image Jim Dirkes  ( 2021-03-29 07:55:05 -0500 )edit

Thank you! I send it to your e-mail.

Martinsquare gravatar image Martinsquare  ( 2021-03-29 08:03:27 -0500 )edit

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Asked: 2021-03-26 14:52:28 -0500

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Last updated: Mar 28