Overwriting default values written by Honeybee

AMIRTABADKANI · December 29, 2019, 4:04am

Since you have developed the HB components based on some default values for each component where needed, is there any way to overwrite these values through Grasshopper interface by additional strings?

For example, I would like to add other features under “People” object where HB compnent does not fill them by default or there is no input for them. So, when I add the required features as a string to EnergyPlus to fill the idf file, instead of overwriting the default values, it creates a separate object as shown in below image that is not sth I am looking for.

Cheers
Amir

chris · December 31, 2019, 5:35pm

@AMIRTABADKANI ,

Unfortunately, there’s no easy way to do this in honeybee-legacy without writing your own OpenStudio measure or editing code within the “Honeybee_Export to OpenStudio” component like this code here, which is where the People definitions are being created in the OpenStudio model using some of OpenStudio SDK’s methods like you see documented here.

Editing these extra properties should get substantially easier in Honeybee[+] when we release the next version this Spring since we will have a Python API that let’s you change the properties of Python objects themselves (before they are exported to EnergyPlus/OpenStudio). You will be able to do this simply using a GHPython component with a couple of lines of Python. For example, to change a the people latent load (which we won’t expose on any Grasshopper components), you just need to change the latent_fraction property of the People object that is assigned to your Zones. So things should be getting easier in the near future.

FYI, I would not recommend using EnergyPlus’s builtin thermal comfort models on the People object when you can control the inputs more finely using the “PMV Comfort Calculator” as you see in this hydra example.

AMIRTABADKANI · January 1, 2020, 9:05am

Thanks a lot @chris for your reply and recommendation and happy new year!

Of course, for this specific example I made, we can use PMV Comfort Calculator and it makes sense to use it, my main question was more about the logic behind the codes that you answered explicitly and I get it.

Because based on what you said, as another example, if I want to use other “HVAC Templates” like HVACTemplate:FanCoil there is no way through HB Legacy at the moment since if I use EnergyPlus I am only able to model “Ideal Air Load” system and if I use OS I am only able to model “ZoneHVAC” objects that are so detailed.

But, if this can be practical in later version of HB+ it will be superb.

Cheers