How to control natural ventilation with multiple schedules? (Custom Python component - honeybee_energy module error)

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1

Hello everyone,

I am currently doing an energy simulation in Honeybee between two thermal zones: a dwelling with an attached winter garden.

My problem concerns the natural ventilation of the winter garden, for which I would like to assign two opening schedules:

  • One for opening to the outside
  • One for opening to the dwelling

This is not possible with the HB Window Opening component.

I tried to create a Python code with AI help for natural ventilation management. However, a “No module named honeybee_energy” error appears and I don’t know how to remove it. I have already reinstalled Ladybug Tools but the error persists.

I’m attaching a screenshot of my error and the context of my simulation.

So I’m wondering if anyone has already created a component for Honeybee Energy with a Python script for natural ventilation?
And if so, how could I fix this error?

Thank you,
Léa

WInter garden simulation
WInter garden simulation1217×815 105 KB

2

Hi @Lea ,

Check out this post for details:

but the short version is: you have to use the ‘old’ python, not the ‘new’ python.

all the best,
@edpmay

2 Likes
3

Hi @edpmay

Thank you for the quick response, I would not have found this solution on my own!

I just tried using the old Python component and retyped the first line to import honeybee_energy, and no error this time. I’m going to try creating my ventilation component and hope that it works.

Thank you very much!

Léa

1 Like
4

Hello everyone,

I tried to create a Python component to manage the opening of different windows but it doesn’t work even after trying several scripts…

Has anyone successfully managed to customize the ventilation of openings within the same HB room? Even using another method than a Python script.

Or is the only solution to split my winter garden into 2 zones?

Thanks in advance,

Léa

5

I think that is correct, the room’s window_vent_control applies to all of the windows of that room. It is a room-property, not a window-property.

You might check out the Air Flow Network tools and see if they might help you setup your condition? I am not sure if they would, but might be worth taking a look:

Screenshot 2025-11-21 at 9.47.21 AM
Screenshot 2025-11-21 at 9.47.21 AM1920×1148 168 KB

best,
@edpmay

1 Like
6

Thank you very much for your advice! I’ll take a look at this component to see if it makes a difference.

Léa

7

Hi @Lea

Easy one but not sure if this works
Assign the schedule of the exterior apertures in the winter garden thermal zone, and the interior aperture schedule in the adjecent thermal zone. I am not sure if this will work, but it’s the easiest to try.

Complex but sure it works
This parameter is indeed defined in room-level in Honeybee, but is a window-level in EnergyPlus. So I would recommend to :

  1. Let the interior and exterior apertures operable
  2. Set the exterior apertures schedule in all zones
  3. Write the IDF with the “HB Model to OSM” component

The next steps are the harder, which necessites to understand how the EMS work.
4. Open the IDF :
4.1 Create the interior schedule (you can copy paste and modify the existing schedule)
4.2 Modify the EnergyManagementSystem:Program corresponding to the interior apertures

This is a complex operation that requires to fully dive into how AFN (AirFlowNetwork) and EMS (EnergyManagementSystem) work in EnergyPlus. If you fully understand it, you can unlock the power of EnergyPlus

Here are some links to help you

1 Like