Water and vegetation features in Honeybee

Hey guys,

I’m trying to model a big glass box with buildings inside like this one:

I would like to investigate the thermal comfort in the “3rd space”. My idea is to introduce water and vegetation features to control the temperatures. Can I model their evapotranspirational abilities with HB?


Hi Christian,

I think your question is very interesting. I think that a possible way to model water with Energy Plus is the following module:

You can find the documentation of it here:

“The Indoor Swimming Pool object is used to describe the indoor swimming pools that are exposed to the internal environment. There are several rules that should be noted regarding the specification of an indoor pool in EnergyPlus. First, the pool is linked to a surface that must be a floor. The pool is assumed to cover the entire floor to which it is linked. If the pool only covers part of the floor in the actual building, then the user must break the floor up into multiple sections […]”


I think it is possible to add this feature to Honeybee.

Hi Chris and Mostapha, what do you think about?


Thanks Antonello!

I will have a look at this. I have posted the same question on Unmethours, in case they have other suggestions.

Link: https://unmethours.com/question/19277/water-and-vegetation-features…

Christian and Antonello,

Very interesting discussion here. Antonello has pointed to the right reference (the EnergyPlus Input/Output reference) for modeling unique building features like the ones you list here. The question of whether you can model these features in the way that you envision depends largely on whether you can find suitable EnergyPlus objects in that web page. The swimming pool seems like it will be sufficient to model the water features but the vegetation may be a bit more complex and you might need to find a substitute.

Since there are no Grasshopper components in Honeybee to model these things, you will have to add them to the HB EnergyPlus model using the additionalStrings_ input on the Openstudio or EnergyPlus components. Here is an example of how to add additional IDF text to a model in grasshopper:


This example is specifically for modeling an evaporative cooling tower, which could be a workaround for vegetation if you get the evaporation of the tower to match your anticipated evaporation from plants in the space (you might have to heavily schedule the cooling tower’s use to do so). Here is another example of using custom IDF text to model a green roof:


The only reason why I think this green roof might to be suitable to model your vegetation is that the E+ reference stresses that this vegetation is only intended for exterior surfaces like green roofs and not interior vegetation. It is also seemingly only intended to model low-lying vegetation and not vegetation from trees, which it seems you might have in your model.

I’m very interested in hearing the answers to the unmet hours discussion as my my suggested workarounds for indoor vegetation are very hacky.