Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
To go from the EF rating value to storage water heater inputs (tank loss and thermal efficiency), you'll want to use one of the following two models that disaggregate these inputs:
They both give pretty similar results.
Since the UEF didn't exist back when those models were created, they both start with EF as the input. If you want to start with EF, you could use the equations provided by RESNET to convert UEF to EF:
| | 2 | No.2 Revision |
To go from the EF rating value to storage water heater inputs (tank loss and thermal efficiency), you'll want to use one of the following two models that disaggregate these inputs:
They both give pretty similar results.
Since the UEF didn't exist back when those models were created, they both start with EF as the input. If you want to start with EF, UEF, you could use the equations provided by RESNET to first convert UEF to EF:
| | 3 | No.3 Revision |
To go from the EF rating value to storage water heater inputs (tank loss and thermal efficiency), you'll want to use one of the following two models that disaggregate these inputs:
They both give pretty similar results.
Since the UEF didn't exist back when those models were created, they both start with EF as the input. If you want to start with UEF, you could use the equations provided by RESNET to first convert UEF to EF:
Edit: There is now a paper documenting the procedure for using UEF: https://www.ashrae.org/file%20library/conferences/specialty%20conferences/2020%20building%20performance/papers/d-bsc20-c039.pdf
| | 4 | No.4 Revision |
To go from the EF rating value to storage water heater inputs (tank loss and thermal efficiency), you'll want to use one of the following two models that disaggregate these inputs:
They both give pretty similar results.
Since the UEF didn't exist back when those models were created, they both start with EF as the input. If you want to start with UEF, you could use the equations provided by RESNET to first convert UEF to EF:
Edit: There is now a paper documenting the procedure for using UEF: https://www.ashrae.org/file%20library/conferences/specialty%20conferences/2020%20building%20performance/papers/d-bsc20-c039.pdfUEF.
