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disproportionately heating loads results

asked 2016-03-30 07:30:33 -0500

ipetidis gravatar image

updated 2017-05-06 08:37:17 -0500

i am student in technical university and i am doing my diploma thesis. i have a problem with the output of heating. The heating loads is very little in compared cooling loads. The results do not match with weather condition for this area! any ideas for this? please if anyone can see the file in the dropbox and give me an advise my email is ipetidis@gmail.com

The dropbox link is simply there for troubleshooting. I am just stuck at the end of the model.

end use consumption

energy consumption

errors and warnings

Link to model.

https://www.dropbox.com/sh/tufydig8ys...

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Comments

1

Sorry to say this, but it is not an appropriate way to ask a question (and we won't send you any email, but you can set your emails preferences so that you will receive an email if an answer is given to you). As with other Q&A sites, this isn't a place where people will do your "homework", at least not from scratch.

Please elaborate on your problem: what are the initial conditions, what isn't working as expected (what did you expect?), what have you tried already? Then we can help.

Julien Marrec gravatar image Julien Marrec  ( 2016-03-30 08:02:57 -0500 )edit

@Julien Marrec Sorry for the posting. I did not mean to imply that i need someone to do it for me (its almost complete) i am just stuck at the end result. The dropbox link is simply there to assist in the trouble shooting.

  • My Heating Consumption is extremely low and i cannot figure out why.
  • for the cooling i set the thermostat to 27 C, and for the heating i set it to 19 C

i tried also to run the model with default scedule sets, constuction sets etc from the library. But the loads chart remains the same.

what could be the issue.

ipetidis gravatar image ipetidis  ( 2016-03-30 10:22:46 -0500 )edit

Number of unmet hours in heating?

Julien Marrec gravatar image Julien Marrec  ( 2016-03-30 11:40:00 -0500 )edit

Did you see the warning about Ground Temperatures?

rraustad gravatar image rraustad  ( 2016-03-30 13:50:16 -0500 )edit

I turn the termostat on in daly base for 365 days of the year. how i can input the values about ground temp in OS or in the IDF file?

ipetidis gravatar image ipetidis  ( 2016-03-30 16:30:13 -0500 )edit

1 Answer

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answered 2016-03-30 18:42:50 -0500

Given the warning regarding ground temperatures, I suspect that zone loads are not representative of your geographic location due to inaccurate heat transfer through the floor surface.

Review the Input Output Reference document for the Site:GroundTemperature:BuildingSurface object.

You can calculate the under slab temperatures using the Slab program in the /Preprocessor folder. See use of ground temperatures and running the slab program in the AuxiliaryPrograms document.

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i changed all the surface in contact with ground to adiabatic , the warning for the ground temp is gone but the pie chart stay same!

ipetidis gravatar image ipetidis  ( 2016-04-01 03:07:25 -0500 )edit

This isn't an answer... it's a comment. Plus, what Richard said in his answer is that he thinks the heat exchange with the ground is underestimated. Changing the surfaces to adiabatic makes thing worse by saying there's no heat exchange

Julien Marrec gravatar image Julien Marrec  ( 2016-04-01 03:12:40 -0500 )edit

Try changing your input file back to using

BuildingSurface:Detailed,
  Zn001:Flr001,            !- Name
  Floor,                   !- Surface Type
  FLOOR SLAB 8 IN,         !- Construction Name
  WEST ZONE,               !- Zone Name
  Ground,                !- Outside Boundary Condition

And then add this to your input file:

Site:GroundTemperature:BuildingSurface,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0;

You should see increased heating energy. Read Section 3 - Ground Heat Transfer in Energyplus found in the AuxiliaryPrograms document.

rraustad gravatar image rraustad  ( 2016-04-01 08:12:34 -0500 )edit

You can also calculate the under floor temperatures using the GroundHeatTransfer objects. Look at example file 5ZoneAirCooledWithSlab. These objects are at the top of that file if using a text editor.

rraustad gravatar image rraustad  ( 2016-04-01 08:36:03 -0500 )edit

i inserted this line Site:GroundTemperature:BuildingSurface,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0,16.0; in the IDF file with text editor , but after i don't know how to run it ?

ipetidis gravatar image ipetidis  ( 2016-04-02 07:33:20 -0500 )edit

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Asked: 2016-03-30 07:30:33 -0500

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Last updated: Apr 01 '16