Assign Radiant_fraction of Sensible gains

ladybug-tools
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Hello Ladybug community,

I am working on setting up occupant internal loads and I’m referencing a guide (“TASK 56”) which states:

    "According to typical office activity level (1.2 met), human presence causes sensible gains (70 W/person) and latent gains (0.08 kg/h/person) [2]. Sensible gains are further divided into convective (60%) and radiative (40%) contributions."

My question is: How do I correctly assign this 40% radiant fraction in Ladybug Tools?

I understand the total sensible gain is 70 W/person, but I’m not sure where to specify that 40% of this (28 W) is radiativeand 60% (42 W) is convective.

Is there a specific input for “Radiant_fraction” on the Honeybee “People” component, or is this value set in a different way?

Thank you for your help!

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Hi Hamed,

I don’t think that we can modify this value in Ladybug Tools. However, EnergyPlus sets the radiative value at 30% by default. You can modify it in the IDF, under the People object : Group – Internal Gains (People, Lights, Other internal zone equipment): Input Output Reference — EnergyPlus 24.2

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@hamed.sangin Hi! SO I think that if you use the add_str input, and utilize the OtherEquipment E+ object; you should be able to accomplish your goals I believe.
best
-trevor

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Hi @hamed.sangin ,

It is possible to change the people radiant fraction in Ladybug Tools but we currently did not expose it on a component. You can see that the radiant_fraction exists in the Ladybug Tools SDK object for People. So you can currently specify it with a custom GHPython component but, to save this issue from coming up again, I just exposed it on the HB People component.

I just pushed the change here:

… and you can get the updated component on your end with the LB Versioner now, which looks like this:

image
image1393×817 51.2 KB

new_people_component.gh (8.7 KB)

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