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cooling load calculation in energy plus

asked 2017-01-22 07:04:07 -0500

lee gravatar image

updated 2017-04-01 15:29:03 -0500

In EnergyPlus, how to calculate the cooling load? I think cooling loads consist of wall conduction, infiltration, conv,cond,rad to window, and ventilation, and internal gain(human, light,machine). So I think the sum of these are the cooling load.

And in EnergyPlus, output names are:

ELECTRIC EQUIPMENT#Block1:CLASS#GeneralLights:InteriorLights:Electricity [J](Hourly)
BLOCK1:CLASS:Zone People Sensible Heating Rate [W](Hourly)
BLOCK1:CLASS_PARTITION_2_0_0:Surface Inside Face Conduction Heat Transfer Rate [W](Hourly)

is it right the lists of "load" ?

I feel confusing that mean of "energy" and "load". I don't know that what is the output name about "load" in Energy Plus.

Please let me know.

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answered 2017-01-23 07:54:56 -0500

You need to look at the Input/Output reference guide for Zone

The cooling/heating "loads" are the following two variables:

HVAC,Average,Zone Air System Sensible Heating Rate [W]
HVAC,Average,Zone Air System Sensible Cooling Rate [W]

You'll note that we're talking here about sensible cooling.

If you want to get total cooling, you need to look at the HVAC system. If you don't have a specific HVAC system designed in your model, you should put a ZoneHVACIdealLoadsSystem and report the following variables (especially the last one which is the sum of the first two):

HVAC,Average,Zone Ideal Loads Zone Sensible Cooling Rate [W]
HVAC,Average,Zone Ideal Loads Zone Latent Cooling Rate [W]
HVAC,Average,Zone Ideal Loads Zone Total Cooling Rate [W]

If this is for sizing purposes, it's worth also noting is that you should really use the Sizing:Zone objects for this. You'll get a epluszsz.csv file where you'll have a row for each zone where you have a Sizing:Zone, and that specifies the load (see output description)

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answered 2017-04-02 20:04:15 -0500

Samin gravatar image

Hi Julian,

I have problem for calculating heating and cooling load. I am using AFN for natural ventilation and my model does not have an HVAC system. I have read the inputOutput Reference for EP. It says "the Ideal Loads Air System is usually the sole conditioning component: the user does not need to specify air loops, water loops, etc. All that is needed for the ideal system are zone controls, zone equipment configurations, and the ideal loads system component." I tried adding different objects, but either I got the "severe" error and the simulation terminated Or I had some warnings and it did not calculate the loads. Can you please list all the objects I need to successfully calculate heating and cooling load? Your help is much appreciated. Sam

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Hi Sam, this is not an answer, but rather a new separate question. Please check the archive to see if this hasn't been asked already, and if not do open a new question (top-right corner of the website, there's a big "Ask a New question")

Julien Marrec gravatar image Julien Marrec  ( 2017-04-03 01:33:16 -0500 )edit

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Asked: 2017-01-22 07:04:07 -0500

Seen: 4,390 times

Last updated: Jan 23 '17