Modelling balanced ventilation with heat recovery [EnergyPlus]

Hi!

I am looking to model a balanced ventilation system with heat recovery, but without linking it to a heating or cooling system. The ventilation system should simply consist of a supply fan, extraction fan and a heat exchanger in between the supply and return ducts to create the heat recovery system (i.e. the heat from the return air is used to pre-heat the supply air).

Looking at the HVAC in the documentation, it seems that all ventilation systems must either be linked to a heating or cooling system, or have no heat recovery at all.

Thanks in advance for your answers!

Gijs_WE

asked 2023-12-04 10:36:35 -0500, updated 2023-12-05 05:58:30 -0500

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@Gijs_WE what simulation tool are you using? Please mention it in the title or body of your post, as well as add a tag so that others can provide better help.

Also, if you can upload your model to Google Drive, Dropbox, etc. and then share a URL for others to download, that would help others provide better solutions.

Finally, can you clarify if there is any outdoor air mixed into the supply air? It sounds like you have 100% recirculation (all supply air is return air, so no outdoor air is mixed in).

Aaron Boranian (2023-12-04 11:43:34 -0500) edit

@AaronBoranian There is outdoor air mixed into the system, in fact all supply air is outdoor air. Only it is preheated using heat from the return air, which is dumped outside of the building (no recirculation). Thanks for your comment!

Gijs_WE (2023-12-05 05:56:56 -0500) edit

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Looking at the HVAC in the documentation, it seems that all ventilation systems must either be linked to a heating or cooling system, or have no heat recovery at all.

No, you can model AirLoops with heat recovery and without cooling/heating coils. Please try it.

If your system has supply/exhaust fans and heat recovery in each zone, ZoneHVAC:EnergyRecoveryVentilator is another option, which does not require AirLoops.

Keigo

answered 2023-12-10 07:25:20 -0500

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I hadn't noticed the EnergyRecoveryVentilator before, I might give that a try and see if it yields very different results. Thanks for the answer!

Gijs_WE (2023-12-11 02:40:23 -0500) edit

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Update 11-12-23: I think I managed to make this work using an AirLoop system. I sized it on ventilation requirement and SPECIFICALLY made sure that the heating and cooling design capacity are set to 0, thus ensuring no heating or cooling will take place. You can find my solution here https://www.dropbox.com/scl/fi/fe4n3o....

Please excuse the mess with the GSHP that is also in there, although you can use that as well if you feel like it ;)

Gijs_WE

answered 2023-12-11 02:34:39 -0500