Issue with Honeybee Window Air Gap

Hi everyone,

I went into an issue with the Air Gap component and a bit of help would be much appreciated.

In order to make my own Windows Materials, I’m used to create custom materials for a pair of glass and use Honeybee_EnergyPlus Window Air Gap to create the air gap between those glass.

Recently, I checked the U value of these windows (using the EP Decompose component) and was really surprised about the results. I ended up with a U value around 2.3 W/m².K for an air gap and 1.6 W/m².K for an argon gap (with a modified version of the HB_window air gap).

So I’ve been trying to understand what went wrong, and it looks like no matter which thickness I specify for the air gap, the U value is still the same (for the air gap and thus for the EP construction component).

I attached a file to illustrate my problem.

Do you have the same problem by using the file attached ?
Is it related to the EP Decompose Component or is there someting wrong with the Window Air Gap component ? Or something else :slight_smile: ?

From what I understand from this post : U-Value from Windows to Honeybee
HB always assume that the air gap is 1cm when calculating the U-value ?
But which U value Energyplus will use for the calculation ?

Thank you for your help.

Alex (493.9 KB)

@alexandre ,

The issue is that we never got the decompose component to give correct U values for window constructions:
EPWindowMat U Value

It is fixed in the new version of honeybee we are releasing soon but just don’t trust that component’s numbers for window U-value right now.

Thank you Chris, good to hear !