Air flow through interior windows

Hello everyone,

I am currently trying to simulate whole-house air flow, but I found that the Honeybee_Set EP Air Flow component only calculates natural ventilation on exterior windows. Is there a way to calculate natural ventilation on interior windows as well? It is important for me to evaluate the effect of cross-ventilation.

Thanks for your reply.

@chfyhpyyy129 ,
You can can get a decent model of a cross-ventilated building by using air walls as your interior surface between zones (where there are interior openings that allow air to pass) and by setting the windDrivenCrossVent_ input to True on the SetEPAirflow component:

Using this method will assume that there’s no resistance to the airflow across the interior of the building. So, essentially, you need some large air walls/interior openings for this to be an accurate model of your building. If your interior opening are small in relation to the openings at your exterior windows, you will likely need to build your own airflow network to account for this resistance using the additionalStrings_ input to the energy simulation component. This is a big task so I’d recommend trying to get the other method to work first if possible.

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Hi, Chris

Thank you for your reply.
The reason why I wanted to create an interior window was that I am trying to study the effect of glazed balcony as buffer zone. The location of the balcony is shown in the picture below. I need to open and close the interior window between the balcony and the living room according to different schedules, for instance, closed during daytime and open during nighttime. Is there a way to model this kind of situation?

Thanks for your help.


It’s still hard for me to understand what you are trying to evaluate here. It doesn’t look like you get much cross ventilation at all in that apartment since you have a lot of interior partitions that would block the flow of air from one side of the apartment to the other. I guess that you could try assuming that all of the doors are open but that still would not be that much cross ventilation since the doors are small.

I also don’t understand why you are modeling the balcony as enclosed. Is this some enclosed green house space or is it open air? If it’s open air, you might be better of modeling it as context shading instead of a zone. If you really think it has so be model as a zone, you could model the window between the two zones as an airwall and adjust the flow between zones according to your day/night schedule using the interzone air flow schedule on the setEPAirflow component.

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Thank you Chris!
The reason why I model the balcony as enclosed is that it is common to have a glazed balcony/conservatory outside the living room here in China, and I want to study the environmental benefits of it. I would try to model the window as air wall and adjust the flow as you suggested.
Thank you again for your help!