Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page

# How can I change the unit from kWh to kWh/m2?

Dear All, I am working on a large experiment in which I compare several variables. The results of this project show the energy consumption for heating cooling and electrical system. I get the value in kWh but I need to have the results in kWh/m2.

Obviously, I could divide the value for the floor area, but the experiment is very large so I would do it automatically.

Have you suggestion?

Thanks

A.

edit retag close merge delete

@Antop Just for clarification, are you using EnergyPlus?

( 2015-02-05 13:02:53 -0600 )edit

Sort by ยป oldest newest most voted

Hi Antonio,

I replied to you on jEPlus forum but just in case you haven't seen an answer I'll repeat it here.

For a clarification, you mentioned you use jEPlus+EA. In this case you have an opportunity to do automatic postprocessing within jEPlus+EA by specifying mathematical operations in rvi (or rvx) file (you can do postprocessing by including python script as well).

Total building area can be extracted from sql. If you choose to output simulation results to sql file (by adding Output:SQLite, SimpleAndTabular; object) you would be able to extract the total building area by using SQL query. From top of my head the SQL query should be:

SELECT Value FROM TabularDataWithStrings Where RowName = 'Total Building Area'

However, if I'm wrong, you'll have to check and update the sql query. YouTube video tutorial can be found here

Having the total building area extracted from sql, you'll be able to calculate normalised energy consumptions and use them as optimisation objectives. For example, if your Heating:DistrictHeating output [in J] is c2, and total building area [in m^2] is c4, the normalised heating consumption would be:

Heating; kWh/m2; c2/c4/1000/3600.

Cheers, IK

more

Without more detail about the outputs you're interested in it's hard to provide a specific answer.

However, the LEED Summary section of the HTML output lists the electrical and thermal EUI by end use in Tables EAp2-17. In the OpenStudio application these can be found here:

Results Summary > Reports > EnergyPlus Results > Table of Contents > LEED Summary

Or by navigating to the HTML output file:

osm file directory > run > EnergyPlus > eplustbl.htm or eplustbl.csv

more

the output are: InteriorLights:Electricity InteriorEquipment:Electricity

Heating:DistrictHeating Cooling:DistrictCooling

Could I have the same results in enrgy plus?

( 2015-02-05 11:58:36 -0600 )edit

To follow up on @MatthewSteen's answer, you could add in the Annual End Use Breakdown measure which gives end use and fuel type breakdown normalized by area. In fact the data is pulled from the tables in the EnergyPlus output that Matt referred to. This report displays in IP units (even thought the EnergyPlus tabular data is SI). But it would be easy for someone to remove the unit conversion to make this report SI.

( 2015-02-05 12:09:16 -0600 )edit

@Antop most if not all of those outputs should be in the tables I mentioned above and yes the HTML and CSV output files are produced by EnergyPlus during an OpenStudio run, is that what you're asking?

( 2015-02-05 12:18:48 -0600 )edit

Hello, can you help me in a similar situation? I have the report of Zone Windows Total Heat Loss Rate [W], but i want it in [W/m2]. Is it possible to have that? Thank you.

more

This is a six year old post and your question is a little different, so it would be better for you to ask your question in a new post. Yes, what you want is possible, but will be easier to answer if you provide some more details. Are you looking at area of window or floor area of space? Are you aggregating to the whole building or space, facade, etc?

( 2021-09-25 12:26:01 -0600 )edit

Hello, ok i'll ask in a new post. What im looking for is area of window and its for the all the windows in the house. This is a case with a single family house.

Thanks

( 2021-09-27 10:54:54 -0600 )edit

Hello,

( 2021-10-04 08:58:49 -0600 )edit