ASHRAE Climate Zone Discrepancy

Hello Mostapha,

I am working in a project in Oklahoma City, USA and incorporated the weather data means ddy and epw file of Oklahoma city which comes under climate zone 3A. But the report generated by pollination shows the ASHRAE Climate zone is 5A. Kindly help me with the discrepancy.

Thanks ,

Hi @pradipta, You have to be more specific in this case. What report are you referring to here? Can you share a bit more context for us to be able to recreate the issue on our end? Thank you!

Hi Mostapha,

I am preparing the report for annual energy use from the model. I am attaching the file herewith for your reference. You can see the climate zone is written 5A when it is 3A in actual.

Hey Chris! Can it be because we create the DDY file from the EPW file? Or is there something else going on here?

I have downloaded the ddy and epw file from the link below and simple put the files as asked and this is the report we are receiving. How to fix?

Hey @pradipta ,

This is a result of some automated routines that we have, which try to guess what the climate zone is based on the DDY criteria. We do this because the vast majority of simulations don’t really care about the climate zone that is specified in the OSM metadata but there are a few measures from NREL that fail when it’s not there. The “OpenStudio Results” measure that’s used to make the HTML report there is one of these measures. The climate zone has no bearing on the simulation or the actual energy use results but it still wants to write it into the report for you.

In any event, if you know what your climate zone is and you want it to show up correctly in the report, you can always manually specify the Climate Zone using the Simulation Parameters. Here is how to do it for your case: (25.6 KB)

You see that you can also use this to change the building program from the default MediumOffice. Just be wary not to set the eff_standard_ unless you want there to be a whole separate sizing run to happen before the annual simulation of your model, which will use the sizing info to set efficiencies for all HVAC equipment but will greatly increase the runtime.

Hello Chris,

Thanks for your prompt reply. We appreciate your time.

How important this ASHRAE climate zones are in calculating the total energy of any building type? For our research we consider this criteria quite important and don’t want to mess around with that. As we are working in pollination with Rhino, we are unable to tweak the settings as mentioned above. Kindly see if it can be solved through some easy steps in rhino.

Looking forward to hearing from you.


Hi @pradipta ,

I’ll confirm again that the climate zone that you see in the report there has no bearing on the energy use of the building or the results that you see in the report. It is only there because OpenStudio SDK wanted to add an extra (often redundant) field for it so that it can write it into reports. But, as you can see here, it often creates more confusion that it helps.

Granted, things like your ConstructionSet will have a big impact on the simulation results and, if you are not creating your own ConstructionSet, you should use one of the ones that we ship with the Rhino plugin, which are organized by version/year of ASHRAE 90.1 and ASHRAE climate zone. So the “cimate zone” of your ConstrucitonSet matters. But this is totally separate from the climate zone that you see in the report there.

In any event, if you want to change the climate zone in the report while using only the Rhino plugin, you just need to use the `PO_SimulationParameters’ command. That will bring up a menu where you can change the climate zone in the simulation parameters.

…And just make sure you get the SimulationParameters from the Rhino model when you submit your study to Pollination.

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Hi Chris,

Thanks for your insightful information. It is really helping me to work with the plugin.

I have one confusion, as you said. I was using the `PO_SimulationParameters’ command, but it is not showing me the climate zone and building type in the window box. Do you have any idea why this is not showing the information? Your help will be greatly beneficial to me.

Thanks & Regards,

Hi @pradipta - This is most likely because you are using an older version of the Rhino plugin. Installing the latest version should include additional items.

In case you can wait for a couple of days, we will release a new version of the plugin in the next few days that includes additional improvements to the Simulation Parameters panel.

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Thanks Mostapha,

It is great news. Let us know when we are getting the updated plugin.

Thanks for your help.


Is this possible for you to tell when can I expect the newer version of the pollination, as discussed.


Hi @pradipta - Sorry that I forgot about letting you know. The new version has been released and you can download it from Pollination.

Thanks, Mostapha,

As I am working in the university computer lab and must ask the IT team to change any modifications. I will request you sending me an instruction guideline for downloading and activating the updated version.




You can share these two links with the IT.

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