Opening different types of windows in a zone

Hello, everyone!

I am modeling a building in Brazil, and this means a lot of natural ventilation! Iam using the “SET EP NATURAL VENTILATION” to open my glazing area and I have a doubt. I have different types of windows in a same zone, and I would like to know if it is possible to set a different “fractionOfGlzAreaOperable” for each façade in a same zone.


@iris_loche ,

This is do-able but some of the calculations will be hard-coded in your Grasshopper definition given how Honeybee legacy is set up right now.

First, I would note that it is relatively straightforward to set up a zone with both operable and fixed windows like so: (488.3 KB)

To set different windows with different fractionOfGlzAreaOperable, you will have to use multiple Set EP AirFlow components for each group of windows facing a given orientation. For each Set EP AirFlow component, you should use the 2 - CUSTOM WIND / STACK VENTILATION option and input the total area and total height of open windows for a given facade. If you need help calculating these values, you will see in the screenshot above that the readMe! output of the component tells you these variables when you use the 1 - WINDOW NATURAL VENTILATION option.

Here is an example of a script where I set the south window to be 50% operable and the east window to be 25% operable: (498.4 KB)

When we eventually add support for the airflow network in Honeybee[+], this process will become a lot more straightforward and you will be able to assign a fraction operable to individual window surfaces.


Hello, @chris! Thank you very much for your reply.
Well, I understand what you have done. But in my case, I have built the geometry in the EnergyPlus plugin for sketchup and have imported all the zones and glazings to grasshopper as an idf file. In this case is it possible to do it in an easier way?

@iris_loche ,

You can use the Decompose Based on Type component to get the window geometries and use the Separate by Normal component to get which ones are facing a given direction. This will help you come up with the window areas more easily but that is the most help that I can give. There’s no speedy workflow for something that requires such a detailed level of control over groups of individual window surfaces.

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Hi all,

With the new version of Ladybug Tools 1.6.0, I cannot use the same method to set different fractions of operable area for different windows. The operable window surfaces should be set before setting the setpoints and the fraction operable area. So in my case, the last fraction operable is considered for all windows…Could you help me with this issue, please?