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Zone Sizing Data with Ideal Loads

asked 2018-01-16 04:54:12 -0500

updated 2018-01-16 20:23:47 -0500

I want to quickly output zone-by-zone heating and cooling loads in the HVACSizingSummaryoutput report. The simplest approach I know is to use an HVACTemplate:Zone:IdealLoadsAirSystemobject. Though I can't seem to get my model to output the Zone:Sizing object like the other templates. For example when I replace the ideal loads air system and useHVACTemplate:Zone:VAVon the same exact model Zone:Sizing is created as it should.

I do have "do zone sizing calculation" selected in SimulationControl, and when I manually add Zone:Sizing, my simulation runs and the HVACSizingSummaryoutput report is populated. I just want to understand why the template isn't doing this like it should.

Here is a snapshot of my idf:

image description

and the expanded idf (no zone:sizing object):

image description

I can see that the zone:sizing object should show up in the expanded idf, as it does in the example file HVACTemplate-5ZonePurcAir, but it does not in my file.

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Do you have zone thermostats and design day temperature schedules defined for the zones in your ideal air loads model?

Lyle K's avatar Lyle K  ( 2018-01-16 18:09:22 -0500 )edit

Yes, and I can add a zone:sizing object myself, manually, and it works just fine.

Anna Osborne Brannon's avatar Anna Osborne Brannon  ( 2018-01-16 18:40:01 -0500 )edit

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answered 2018-01-17 02:34:42 -0500

bbrannon4's avatar

You need to have it specified in simulation control, and something set to autosize in the template objects (some airflow or capacity or something), otherwise the simulation doesn't have anything to autosize. Leaving them blank defaults to unlimited, which doesn't call for sizing.

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answered 2018-01-16 06:05:17 -0500

Avi's avatar

updated 2018-01-16 11:37:35 -0500

Expand does create sizing:zone object. make sure you specified in simulationcontrol sizing.

  Yes,                                    !- Do Zone Sizing Calculation
  Yes,                                    !- Do System Sizing Calculation
  Yes,                                    !- Do Plant Sizing Calculation
  Yes,                                    !- Run Simulation for Sizing Periods
  Yes;                                    !- Run Simulation for Weather File Run Periods
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Yes, I have the zone sizing simulation control specified. I tried it on an example file and it works as you said, but it does not work in my file. I must have something else wrong, so I'll keep digging. I've updated the question with more details.

Anna Osborne Brannon's avatar Anna Osborne Brannon  ( 2018-01-16 16:16:22 -0500 )edit

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Asked: 2018-01-16 04:54:12 -0500

Seen: 715 times

Last updated: Jan 17 '18