HB Peak and Annual Load doesn't run

Hi, I installed ladybug tools 1.2.0, everything works (daylight, energy simulation, etc.) except the HB Peak/Annual Load. The error message points to compatibility:

  1. Solution exception:The installed EnergyPlus is not version 9.4.0 or greater.
    Get a compatible version of EnergyPlus by downloading and installing
    the version of OpenStudio listed in the Ladybug Tools compatibility matrix
    1.4 Compatibility Matrix · ladybug-tools/lbt-grasshopper Wiki · GitHub.

But I installed the versions according to the compatibility matrix:
EnergyPlus: 9.4.0
OpenStudio: 3.2.1
Appreciate your help!

According to the compatibility matrix the supported OS is 3.2 (not 3.2.1).
Maybe this is the reason …

Hi Zhou,

I came across the same problem. Only Annual Load cannot work. And when I checked the energyplus version, it returns the time rather the version. I don’t know why.

I fixed the problem by following exactly the compatibility matrix, i.e., OS 3.1.0 and OS Application 1.1.0

Thanks a lot. That’s the solution.

Yes, sorry about that. This is because EnergyPlus changed their command line interface on us between E+ 9.4 and 9.5. There’s a fix for this in the latest development version of the LBT plugin but it hasn’t made it into a stable release yet (it will be there when we release LBT 1.3).

In any case, you should always use the version of OpenStudio in the compatibility matrix as Abraham says.

Hi Chris,

I noticed the HB Peak Loads output peak_cool is smaller than the max value of the cool_bal sum, do you know why?

Yes, I do. The cool_bal sum is a measure of the instantaneous load in the space. You can imagine that this sum would be equivalent to the cooling load if the Room has zero thermal mass. However, almost all EnergyPlus models will have thermal mass (there’s at lest the mass of the constructions) and this mass will soak up the instantaneous load and gradually release it to the air of the room where it can be removed by a cooling system.

In short, this thermal mass will result in the peak cooling coming after the peak instantaneous load and will also mean that the cooling load is “smoothed out” due to the thermal lag. So relationship between the cooling load and the sum of the instantaneous loads will look like the following:

I hope that clarifies things.

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Thank you so much chris!