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Multiple SwimmingPool:Indoor objects do not work

asked 2023-02-04 09:26:05 -0500

Keigo's avatar

updated 2023-02-05 14:50:53 -0500

A bug report. Two or more SwimmingPool:Indoor objects do not work properly.

Let me explain using ExampleFIle: 5ZoneSwimmingPool.idf. Oroginally, the examle file has one SwimmingPool:Indoor object, so it works properly. When I added 4 SwimmingPool:Indoor objects (all 5 zones have SwimmingPool:Indoor objects), only "Test Pool5" met the pool setpoint temperature of 27ºC.

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The order of the objects matter. When I changed the order as shown below, only "Test Pool" met the pool setpoint temperature.

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But the problem is more complicated. I explain using the revised example file with 2 SwimmingPool:Indoor objects just because 5 pools are too much to explain. The hot water plant loop is as shown below. When there are 2 SwimmingPool:Indoor objects,

  • HW SUPPLY OUTLET NODE:System Node Temperature does not meet the Setpoint of 82ºC.
  • HW SUPPLY OUTLET NODE:System Node Temperature and HW DEMAND INLET NODE:System Node Temperature are inconsistent.
  • TEST POOL:Indoor Pool Inlet Water Temperature and POOL WATER INLET NODE:System Node Temperature are inconsistent.
  • TEST POOL2:Indoor Pool Water Temperature meet the Setpoint of 27ºC even if TEST POOL2:Indoor Pool Inlet Water Temperature is lower than 27ºC.

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It's a mess. The bug extends beyond SwimmingPool:Indoor objects to the entire hot water loop, so that zones cannot meet the heating temperature setpoint.

The idf files are here (V22-2-0). You can reproduce the bug.

Personally, I have a few projects with multiple swimming pools, and I don't have time to wait for the future EnergyPlus version to fix the bug... Please let me know if anyone has been able to force multiple SwimmingPool:Indoor objects to work using EMS or other means.

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One makeshift I came up with:

  1. Prepare an idf file which has only one SwimmingPool:Indoor object.
  2. Run simulation and get the annual heating load profile of the SwimmingPool:Indoor.
  3. Iterate Step 1 and Step 2 for all SwimmingPool:Indoor objects.
  4. Replace all SwimmingPool:Indoor objects with LoadProfile:Plant objects for the final idf file.

I don't need to know the water use of the swimming pools. This makeshift may be the most accurate to know the annual energy use at the moment although it cannot simulate the water evaporation and the pool surface temperature.

Keigo's avatar Keigo  ( 2023-02-05 11:47:10 -0500 )edit

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answered 2023-02-05 05:17:18 -0500

Jim Dirkes's avatar

Dear Keigo,

Before E+ had a pool object, I developed a swimming pool calculation procedure that uses:

  • The Shah procedure for deriving indoor evaporation
  • Creating an OtherEquipment latent load that is equivalent to the evaporation
  • Creating an OtherEquipment evaporation (cooling) load that is equal and opposite to the evaporation
  • Using an air loop and heating system with properties matching those specified.

The procedure works well. If you would like more detail, please send an email to me using my UnmetHours contact information

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Thank you for your comment. I'm interested in your calculation procedure, but your profile is blank. Where can I find your email address?

Keigo's avatar Keigo  ( 2023-02-05 06:57:04 -0500 )edit
Jim Dirkes's avatar Jim Dirkes  ( 2023-02-05 08:03:47 -0500 )edit

answered 2023-02-05 11:21:13 -0500

There is a bug report on this very issue. It was recently assigned to an EnergyPlus developer, so maybe it will be fixed for the next release? You might also track the issue and test out any proposed bug fix to make sure it addresses your issues.

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Oh, coincident. I will keep a close eye on the issue.

Keigo's avatar Keigo  ( 2023-02-05 20:09:32 -0500 )edit

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Asked: 2023-02-04 09:26:05 -0500

Seen: 126 times

Last updated: Feb 05 '23