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Designbuilder/EnergyPlus Relief fan

asked 2017-08-11 07:58:01 -0500

kbk78 gravatar image

updated 2017-08-11 07:58:44 -0500

How do I setup a relief fan on the AHU in designbuilder or energyplus. The fan would need to track the outdoor air flow including increased outdoor airflow during economizer mode.

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answered 2017-08-16 14:15:38 -0500

Hi @kbk78

Not sure if you figured this out already. In EnergyPlus, the outdoor airflow is controlled using the object Controller:OutdoorAir . Based on how you want to model the economizer, you can look for the appropriate selection using the E+ I/O ref guide. You can then model the limits according to your system control sequence of operations.

This controller is applied to AirLoopHVAC using a AirLoopHVAC:ControllerList.

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Hope that answers your question!

  • Raghu
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@Raghu, question is about modeling a relief fan not about modeling economizer. The return fan on the AHU moves the return air from the zone to the AHU. But the relief fan exhausts the excess air (that was brought in as outside air) from the return air to the outside to keep the airflow in balance. Though we can include a zone exhaust fan it does not pass through the AHU heat recovery coil and also the exhaust would not increase if the AHU is in economizer mode.

kbk78 gravatar imagekbk78 ( 2017-08-16 15:43:28 -0500 )edit

Could you explain the system that you are trying to model and how you intend to control it?

rsunnam gravatar imagersunnam ( 2017-08-16 15:49:46 -0500 )edit

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Asked: 2017-08-11 07:58:01 -0500

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Last updated: Aug 16