Face Energy Flow - HB Thermal Load Balance

Hello everyone,

I am trying to analyze the energy balance of a thermal zone in HoneyBee, but it does not show me the result of the energy gains and losses due to opaque surfaces, the result is zero. Through the custom results, looking for the specific output variable Surface Average Face Conduction Heat Transfer Energy, I can see that the thermal zone has effectively exchanged for the opaque surface.

So does anyone have an idea what I’m doing wrong?

Thank you in advance.

The best!.

Update. I was observing the results, and Face Energy Flow only generates results from glass surfaces. Why doesn’t it generate results for opaque surfaces? I need de opaque surface heat balance.

Maybe @chris you have comments about it.

Thank you in advance.


It is difficult to say without an model. Perhaps the opaque surfaces are set to adiabatic.


Yes, I didn’t want to upload the file because it’s a bit heavy. Now I’ve cleaned it up a bit. Here I leave it.

_Balance.gh (319.1 KB)

Stay tuned to your comments.

Thank you very much.


Hey @cerianipascual ,

I’ll try to check your file but have you tried creating a load balance using the HB Annual Loads component? If that one has the opaque energy flow, then we know it’s an issue with thae wrong outputs requested from E+. Otherwise, it’s an issue with your model as Erik said.

Here’s a sample file for computing a load balance with Annual Loads

Hello! Thank you very much for your comments and suggestions.

I tried to run HB Annual Loads, but it gives me an error: 1. Solution exception:model_to_idf() got an unexpected keyword argument ‘patch_missing_adjacencies’

I was searching on the internet how to fix it, and I found this possible solution, I don’t know if it’s for it: Annual Loads patch missing adjacencies v1.4.1

But the problem is that now I’m afraid to update anything from LadyBug, since I’m about to finish my research and if I update the components and then it doesn’t work, I don’t know what to do.

I’ve checked the model, and of the zones I’m analyzing, none of its surfaces are adiabatic.

On the other hand, HB Annual Loads does not run if I use natural ventilation at certain times of the day?

Thank you very much.

Hello! Updating here.

After reviewing the Thermal Balance code at honeybee_energy.result.loadbalance — honeybee energy documentation. I have seen that the Energyplus output variable ‘Surface Inside Face Conduction Heat Transfer Energy’, which it uses to calculate the OPAQUE_ENERGY_FLOW was not being requested in my model. I thought that like all the other variables you use for the heat balance calculation, it would be requested by default. Now I have managed to obtain the information on the thermal balance, although it still does not close exactly.

In any case, I have the doubt, and surely because of my ignorance on the subject. Why is this variable (‘Surface Inside Face Conduction Heat Transfer Energy’) used in the Thermal Balance, and not others such as Surface Inside Face Convection Heat Gain/Loss, which better represent the heat gained or lost in the thermal zone? It’s probably for some reason I don’t know.

Thank you very much.


This is the source of your problem. The components that you are using on your canvas are not aligned with the version of the Ladybug Tools core libraries that you have installed on your machine. The best way to fix things is to just reinstall Ladybug Tools by running the Pollination Grasshopper single-click installer. This will ensure that all of libraries and components are compatible with one another. Then you can use the LB Sync Grasshopper File component to ensure that the Grasshopper scripts you have developed are aligned with your installation.

I promise you this will fix things and this is much better than trying to force your currently broken installation to do what you want.

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