Infiltration model in Honeybee

Hi there!

I am trying to validate some results i get from a honeybee energy simulation, and i am getting high discrepancies whenever i turn on the infiltration (meaning the air-leakage, unwanted infiltration that is supposed to be occurring through the building fabric). Is there a possible way that i could set the energyplus infiltration model coefficients through honeybee? There should be 4 such coefficients: A.Constant coefficient, B.Temperature coefficient, C. Wind speed coefficient (linear) D. Wind speed coefficient (quadratic).

thank you!

Ok i searched a bit more on the possible cause of the error, and it seems that the “energySimPar” component cannot accept other values for “timestep” and “terrain” apart from the default values that are now “6” and “City” respectively. The “terrain” was the one creating the problem!

Hope it helps you great developers!

Hi Iason,

I’m not sure if I fully understand the relation between the first question and this comment. Back to EnergySimulationPar I just did a quick test and it works as expected. You can change both the terrain and timestep and they will change inside the .idf file.

Back to the original post can you help me to understand what is the exact EnergyPlus object that you’re trying to change? Do you have a reference idf file? You should probably be able to set it up using additionalStrings_

Mostapha

Hi Mostapha,

i was checking the idf file and it was not changing neither for timestep nor for terrain. But in your snapshot it looks fine… I am opening the idf with the energyplus idf editor like you do. Here’s the file.

The object i was changing was the infiltration rate on the HB Loads component. But it seems it is working just fine (checked with idf) and my problem was with the “terrain” where i thought it was on 3 but it was stuck at 0.

Can you explain how i can fix it?

Always thanks!

unnamed.idf (46.1 KB)

Hi Iason, I’m not sure if this file is generate with the same script as this discussion but if that is the case your input is set to 0. Am I right?

Yes that is the file,

eventually i put it to zero so i would not be confused. If i change it, there is no difference in the results (e.g. heating energy) and the idf shows the terrain value to be still 0. I Hope i am not confusing you… And the timestep remains constant, as the idf shows, so i also let it be 6 just to avoid confusion.

Ok. I took another look and it’s happening because you’re using a single number for shadowCalcPar input which is wrong and so the component overwrites the values to default. You should use shadow calculation parameters component to define the input parameters.

I added an extra check for the next release so it gives you a proper error message.

You are right!

I didn’t see that, it already says on the energysimPar component that one should use the shadowPar. My bad.

Now it works, case closed!

Thank you for your help!