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 | 1 | initial version |
This is one solution you can try. Others may suggest more suitable solutions for your specific needs. Full disclosure, I co-authored the following solution with Dan Macumber.
If you're willing to use OpenStudio (App or SDK) as an intermediate tool, you can try out the Thermal Bridging and Derating (TBD) measure. It will automate the tasks you're describing, aside from customizing the actual PSI-factors you have on hand. A good idea is to first peruse through the online Guide, then maybe go through a handful of UMH posts (here, here and here).
IDF geometry (i.e. surfaces) and constructions, once imported using OpenStudio, remain generally intact (i.e. no information loss). So it's usually safe to:
... before completing your IDF model (e.g. HVAC, lighting). This works well when importing a bare-bones IDF.
If your model is instead in an advanced state (complete with HVAC, lighting, etc.), then the import IDF > apply TBD > export IDF route is certainly trickier. In a nutshell, OpenStudio doesn't import e.g. HVAC, lighting, SHW objects. So you would avoid building directly upon an exported IDF in such circumstances. Instead, you would parse the exported IDF to recover the newly created, surface-specific (derated) constructions/materials. Then use some script-based macro (e.g. Python, Ruby) to replace the initial constructions/materials in the original IDF, with the surface-specific derated materials/constructions from the newly exported IDF. This is fairly straightforward, as TBD relies on a surface's name (e.g. "North Office Wall") to label its new derated construction ("North Office Wall c tbd") and its derated insulated material ("North Office Wall m tbd"). I've helped out EnergyPlus users with this in the past, even IES-VE users. I admit however that this isn't ideal if one is unfamiliar with scripting macros.
I hope this may be of some help.
| | 2 | No.2 Revision |
This is one solution you can try. approach. Others may suggest solutions that are more suitable solutions adequate for your specific needs. you. Full disclosure, I co-authored the following solution with Dan Macumber.
If you're willing to use OpenStudio (App or SDK) as an intermediate tool, you can try out the Thermal Bridging and Derating (TBD) measure. It will automate the tasks you're describing, aside from customizing the actual PSI-factors you have on hand. A good idea is to first peruse through the online Guide, then maybe go through a handful of UMH posts (here, here and here).
IDF geometry (i.e. surfaces) and constructions, once imported using OpenStudio, remain generally intact (i.e. no information loss). So it's usually safe to:
... before completing your IDF model (e.g. adding HVAC, lighting). lighting, etc. This works well when importing a bare-bones IDF.IDF: geometry + constructions.
If your model is instead in an advanced state (complete with HVAC, lighting, etc.), then the import IDF > apply TBD > export IDF route is certainly becomes trickier. In a nutshell, OpenStudio doesn't import e.g. HVAC, lighting, SHW objects. SHW, etc. So you one would avoid building directly upon an exported IDF in such circumstances. Instead, you one would ideally use some script-based macro (e.g. Python, Ruby) to:
This is fairly straightforward, as TBD relies on a surface's name (e.g. "North Office Wall") to label its new derated construction ("North Office Wall c tbd") and its derated insulated material ("North Office Wall m tbd"). ").
I've helped out EnergyPlus users with this approach in the past, even IES-VE users. users (via gbXML). I admit however that this isn't ideal if one is unfamiliar with scripting macros.
I hope this may be of some help.
