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thermal discomfort

asked 2021-08-05 18:14:50 -0500

Melina gravatar image

updated 2021-08-18 13:54:03 -0500

Hello to everyone I've simulated a residential building in EnergyPlus and my zone control is dual setpoint. I want to define any hours as an unmet hour or thermally discomfort when the temperature rises more than 1C from the setpoint in cooling season or when is below the heating setpoint of more than 1C. But I don't know how can I do that! Now I just can see the unmet hours in the results (tables) and it is not useful for me because it counts any second that the temperature differs from setpoint more than 0.2 C.

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answered 2021-08-07 12:12:20 -0500

Melina gravatar image

I found this on bigladder website and my problem is solved:

Zone Heating Setpoint Not Met While Occupied Time: Hours when the zone temperature is lower than 0.2 (default) degrees C below the heating setpoint and when people are present in the zone. To change the reporting range from 0.2 degrees C, see the OutputControl:ReportingTolerances object.

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answered 2021-08-05 20:06:43 -0500

sashadf1 gravatar image

updated 2021-08-05 20:11:02 -0500

I saw in a previous post that you are using ResStock.

If you are using a version of ResStock that uses PAT (v2.2.5 or prior), you can change the setpoint tolerance from 0.2 C up to 1C for both the heating and cooling setpoint by editing the EmptySeedModel.osm file. This should be the seed model file for all your PAT ResStock measures.

Find the EmptySeedModel.osm file in this directory within your ResStock download: OpenStudio-BuildStock-2.2.5\project_singlefamilydetached\seeds. It should be in that location for v2.2.5 because it is in that location for v2.2.4, and the differences between those two ResStock versions are minimal.

A way to reduce unmet hours is to change the Heating and Cooling Setpoint tolerance in the OpenStudio model itself.

Head to the Simulation Settings section, unhide Output Control Reporting Tolerances, and change the tolerances to 1 Kelvin (i.e., 1C) for both setpoints (heating and cooling). Mine are set at 0.556 K (1 Rankine), but from your question it looks like you want them to be 1C.

Output Control Reporting Tolerances in EmptySeedModel.osm

Unmet hours will trigger when the control/thermostat zone temperature differs from the setpoint by more than the tolerance (or throttle zone).

Check the unmet hours in your results.csv file in localResults for ResStock. They should be reduced as the tolerance increases.

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Thank you very much for your responses. Actually, I'm not using OpenStudio right now (maybe I have to in the future) I'm looking for a way to do that in EnergyPlus. Is it possible? About my both questions (Unmet hours within 1C difference with setpoint and using ResStock) is it possible to do with EnergyPlus? Or do I have to learn using OpenStudio?

Melina gravatar image Melina  ( 2021-08-07 11:56:26 -0500 )edit

ResStock v2.2.5 and prior are PAT projects that leverage OpenStudio and the OpenStudio SDK. All the computations (Zone Heat Balance, HVAC, etc.) are done using EnergyPlus (which is the engine), but the actual model is constructed as an OpenStudio model (osm). ResStock's measures like Apply Upgrade and Build Existing Model are OpenStudio measures that affect the osm, not EnergyPlus measures that affect the IDF. The forward translated in.idf file is written to localResults, as is the matching osm file for each datapoint generated.

sashadf1 gravatar image sashadf1  ( 2021-08-08 23:43:53 -0500 )edit
1

Add on:

OpenStudio .osm objects get forward translated to EnergyPlus IDF objects. Sometimes, an EnergyPlus object does not have an equivalent in OpenStudio, but for many E+ objects, there is an OS counterpart.

In this case, you were able to solve your problem by directly editing the inputs in the EnergyPlus OutputControl:ReportingTolerances object. The solution that I posted yields the same result but obtained rather by editing the seed osm file in the OS App.

sashadf1 gravatar image sashadf1  ( 2021-08-08 23:55:02 -0500 )edit

Thank you very much for your explanation. I think maybe I should try using OpenStudio

Melina gravatar image Melina  ( 2021-08-09 10:01:40 -0500 )edit

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Asked: 2021-08-05 18:14:50 -0500

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Last updated: Aug 07