Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
This is a surprisingly complicated and thorny topic. Here are a few considerations:
Watch this Youtube video on HP performance, particularly the part where @Neal Kruis mentions how much bad data there is in the NEEP database. They are working to fix it, but I don't know what the current status is.
Review the proposed RESNET Addendum that is meant to standardize best practices on how to model these systems. However, note that it is not final and we have already provided some feedback that is resulting in changes for the next draft.
It's surprisingly tricky to get the EnergyPlus model right if you plan to use the Table:Lookup object to define the NEEP datapoints. There is a lot of rope to hang yourself with, you need to be very careful and triple-check the EnergyPlus results. See my description here for some context on one such issue.
Getting the details right about backup/supplemental heating, crankcase heating, pan heaters, etc., can swing the results substantially.
OpenStudio-HPXML, and therefore all products that sit on top of it (like ResStock), currently allows NEEP-based ccASHP inputs to be directly specified and ensures the EnergyPlus model is appropriately configured. It's in the process of a being updated based on the RESNET Addendum. Another reference is the resdx python library.
Hopefully someday this will all be easier. For example, some people hope that ASHRAE Standard 205 will ultimately provide detailed, model-specific data to drive the energy simulation without the need for substantial assumptions or data extrapolation.
