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Annual heat demand as OpenStudio output variable?

asked 2018-05-08 17:39:43 -0500

Jono's avatar

updated 2018-05-08 20:12:22 -0500

I'm wondering if anyone knows if total heat demand exists as an openstudio output variable, as I can't seem to find it. By total heat demand I mean the sum of: air infiltration losses + building envelope losses + energy to heat ventilation air.

The way I am currently getting this number is by running Ideal Air Loads, then recording that number as the total heat demand. However, when heat recovery is involved, ideal air loads cannot be used, so I have to make an equivalent heating source that is 100% efficient to match the ideal air loads scenario, then add heat recovery equipment. This method is relatively time consuming so wanted to know if there is a built in feature that could be used.

Thanks for your help!

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answered 2018-05-11 01:33:57 -0500

Avi's avatar

updated 2018-05-26 09:08:02 -0500

I believe that if you use the NERL BCL Ideal Air Loads Options measure you can include heat recovery. (if it fails you can try the E+ measure I wrote that works fine for me) Then if you use OS report measure you will have the total annual heat demand as output in the report.

Edit after looking at the model:

I can't confirm your observations , I was able to run your model with Ideal Air Load System option measure and got the following results:

Without ERV:

image description

And with ERV:

image description

I used LaPaz for weather Data and add 1 air change per hour to your's Design Specification Outdoor Object in order to emphasize the ERV effect.

I believe that you should be able to replicate my observation if you make sure you are using proper weather data.

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Thanks a bunch Avi; I'll give both a try.

Jono's avatar Jono  ( 2018-05-11 12:55:37 -0500 )edit

I tried running the measures but I keep getting the following error: * Severe * Sizing:Zone Name, duplicate name=THERMAL ZONE 1

After looking at the in.idf file, I noticed there were two sizing:zone parameters with a "Zone or ZoneList Name" as THERMAL ZONE 1. One was in the middle of the file and one at the end.

Any clue how to resolve this issue?

Jono's avatar Jono  ( 2018-05-17 20:34:49 -0500 )edit

@Jono if you could post a link to your model I will take a look at it.

Avi's avatar Avi  ( 2018-05-18 00:15:14 -0500 )edit

Thanks @Avi. I've uploaded my model here:

Please don't spend too much time on it :)

Jono's avatar Jono  ( 2018-05-23 13:47:50 -0500 )edit

Strange, must have been something to do with my weather file I guess. Look forward to playing with this measure more in the future. Thanks again!

Jono's avatar Jono  ( 2018-05-29 14:17:00 -0500 )edit

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Asked: 2018-05-08 17:39:43 -0500

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Last updated: May 26 '18