Workaround for EnergyPlus Construction Layer Limitation

The EnergyPlus documentation is clear that the Construction object cannot support more than ten layers. Are there any workarounds to this that anyone here has had success with in the past? Thank you very much for your help!

Comments

Out of curiosity, what kind of construction are you trying to model that requires more than ten layers?

shorowit (2022-03-03 11:14:47 -0500) edit

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Edit: guess my first answer won't work. Other thing I can recommend is combining layers, a fairly straight forward process for continuous layers (i.e. when you don have to account for thermal bridging), lots of info online on how to do it for discontinuous layers as well.

I think you can update the EnergyPlus idd file to expand the Construction object to include more layers:

...
       \object-list MaterialName
  A10, \field Layer 9
       \type object-list
       \object-list MaterialName
  A11; \field Layer 10
       \type object-list
       \object-list MaterialName

Becomes

...
       \object-list MaterialName
  A10, \field Layer 9
       \type object-list
       \object-list MaterialName
  A11, \field Layer 10
       \type object-list
       \object-list MaterialName
  A12; \field Layer 11
       \type object-list
       \object-list MaterialName

Alternatively, you could combine layers/materials prior to defining them in EnergyPlus.

1.5k

willyJohan

answered 2022-03-03 14:31:24 -0500, updated 2022-03-03 15:59:57 -0500

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Changing the IDD will only affect how IDF Editor will allow you to change input fields, but not how the EnergyPlus engine will use them -- you would need to build a custom EnergyPlus executable after making the IDD changes for those to have an effect on calculation processes.

Combining similar adjacent layers is likely the easier & faster option.