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best output variable for latent cooling/Heating ?

asked 2016-05-30 08:04:03 -0600

shahin1992's avatar

updated 2016-05-31 09:23:19 -0600

In a previous question asked on this site before I learned how to get sensible heating/ cooling loads but when I gave the output results to my professor he was not happy with them, he told me I need to get also the total latent Cooling/ heating loads so I sum the sensible and latent loads to get the total loads on my model.

What is the best output variable to use to get latent cooling/ heating loads?

I also used the "Zone Total Internal Latent gain rate " and my professor told me it should be the total Latent load not the gain rate.

image description

I'm using Openstudio software.

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link text is not an appropriate caption for a link, you have to modify the thing that's within brackets. please. I think I already told you to get familiar with Markdown, see this one page cheat sheet for starters

Julien Marrec's avatar Julien Marrec  ( 2016-05-30 09:29:58 -0600 )edit

Done, thanks :)

shahin1992's avatar shahin1992  ( 2016-05-30 23:19:18 -0600 )edit
1

Yeah so change "Link text" to something that's explicit.

In a previous question asked on this site before I learned how to get sensible heating/ cooling loads...

Julien Marrec's avatar Julien Marrec  ( 2016-05-31 01:32:41 -0600 )edit

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answered 2016-05-30 09:28:23 -0600

updated 2016-05-30 09:34:32 -0600

Before asking such questions, make sure you check the following resources:

  • See if a similar question hasn't been asked on unmet hours. This question is very similar
  • Check the Input Output Reference guide of EnergyPlus. Each object is described, and includes the output variables that are available. If your model has Coil:Cooling:DX:SingleSpeed objects for example, this section is pretty limpid.
  • Open the eplusout.rdd after a run... it lists ALL the output variables that are available for you, and doing a search on "Latent" will quickly tell you which one you need. See the answer by Aaron to see how to open it from within the openstudio application on the question I linked above or you can also find it in your file explorer. If your model is called "mymodel.osm" it'll be in mymodel\run\5-EnergyPlus\eplusout.rdd

Now, you won't find this at the zone level, as highlighted in the I/O reference guide here there is no output variable for zone latent load.

You'll find this at the HVAC level. I already showed you which one you need in the case of a Coil:Cooling:DX:SingleSpeed for example, here is the same if you're using ZoneHVAC:IdealLoadsAirSystem

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Thank you very much for your reply, first I did check the mentioned question, and that’s why in the attached picture I used Zone Total Internal Latent gain rate as an example but it’s not what I’m looking for, I’m looking for the total latent loads to be added to the total sensible loads to get one number for Cooling/ Heating thermal loads given hourly as in 8760*2.

i don't understand why is it so complicated to get some basic data like thermal Cooling/heating loads!!

shahin1992's avatar shahin1992  ( 2016-05-31 03:31:47 -0600 )edit

these variable can be useful to me but when I use them in openstudio as an output variables I get no data.

image description

I don’t understand why is it very complicated to get a very basic output like Cooling/Heating total thermal load !!

shahin1992's avatar shahin1992  ( 2016-05-31 03:35:29 -0600 )edit

Because you probably DON'T have an ideal loads system in your building. I specifically told you "Now, you won't find this at the zone level, as highlighted in the I/O reference guide here there is no output variable for zone latent load". Seems like Cooling Coil Latent Cooling Rate is what you would likely need. As said, this won't give you zone by zone unless you have single zone systems with cooling coils.

If you do want zone loads, use an ideal loads system.

(When you paste pictures in the comment box, you really have to resize them or it completely messes up the layout)

Julien Marrec's avatar Julien Marrec  ( 2016-05-31 04:08:51 -0600 )edit
1

And I understand your frustration, the learning curve of E+ is steep and it can be cumbersome sometimes to do things that should be simpler. But don't loose your cool and eventually you'll get it.

Julien Marrec's avatar Julien Marrec  ( 2016-05-31 04:11:54 -0600 )edit

thanks very much for your reply but yet i still need total loads for heating and cooling at any level, i asked for the zone level since i already have the Sensible Cooling/ Heating by zone level but if i can get one for total thermal loads " Sensible+ Latent" for the whole building that would be great. i'm asked to deliver these loads as an assignment to my professor and i was asked to use a domestic Japanese software if i couldn't get the data through this program and my Japanese level is yet not good enough so i need to figure out something through Energyplus or Openstudio. regards

shahin1992's avatar shahin1992  ( 2016-05-31 04:47:16 -0600 )edit

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Asked: 2016-05-30 08:04:03 -0600

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Last updated: May 31 '16