Rater Field Guide
Modeling and Software Options
The Duke Energy RNC Program accepts REM/Rate and Ekotrope energy models for rebate calculation purposes.
Ekotrope models can be submitted for program incentives using the following instructions:
All REM files processed by the program on or after October 10, 2018 will be processed using v15.7.1. See our News page for the announcement.
How to use the UDRH
Current UDRH (5.20.19)
On This Page:
No RNC homes may be sampled. The program requires 100% testing of homes.
"Look back ratings"
All RNC homes must be inspected at rough-in and final. More details are available here.
Builder Verified Items
All items in a submitted home energy model must be field verified by a rater in accordance with Section 5.1.4 of ANSI/RESNET/ICC 301-2014. This includes lighting, appliances, and ceiling insulation.
Homes that do not meet the HERO infiltration testing targets can meet HERO requirements via the visual inspection pathway. It is expected that homes taking advantage of this option follow the HERO code guidance and complete the visual infiltration checklist as required. REM files for these homes must indicate "Visual Inspection" on the Infiltration page. These homes do NOT qualify for HERO + HERS incentives ($/kWh) - only for the flat $750 incentive.
LTO vs Total Leakage:
Per NC HERO code amendment, a home meets the mandatory leakage requirement when either the ducts' leakage-to-outside or total leakage is at or below 4%.
Deemed Savings Items:
Homes with conditioned or unvented-enclosed crawlspaces will receive 650 kWh of savings in addition to the savings shown in the fuel summary report.
ENERGY STAR washers receive 397 kWh of savings in addition to the savings shown in the fuel summary report.
Rater must verify installation of qualifying washer and model as such in REM/Rate file.
Note that washer inputs must not be adjusted after selecting "ENERGY STAR" in the washer menu drop-down.
Adjusting inputs may result in homes being processed without the deemed savings.
Model these systems as ASHPs/ACs with REM default duct system size (based on sqft served). Set duct location to 100% conditioned and no leakage.
Annual kWh generated by photovoltaic systems is not factored into incentives. Raters may submit REM files with PV systems modeled, however, the program will remove all associated savings during the rebate calculation process. (The UDRH automatically removes PV savings when generating Fuel Summary Reports.)
Partial Slab Edge Insulation:
A slab without a fully insulated perimeter (e.g. no insulation between main body of home and garage and/or porch) should be modeled as follows: Determine the percentage of slab perimeter that is insulated and the percentage that is uninsulated (linear feet). Model two slabs, one insulated and one uninsulated, with areas divided proportionally according to the perimeter percentages.
E.g - 900 hsft slab; 120' perimeter, with 30' uninsulated (25% uninsulated vs. 75% insulated)
Model 2 slabs: 1 slab with 30' perimeter and 225 sf area (25% of 900); 1 slab with 90' perimeter and 675 sf area (75% of 900)
Dual Fuel Heat Pumps (DFHPs):
In REM/Rate, set the equipment to library-type "Air source heat pump" and match the efficiencies of the installed DFHP. Set the equipment in REM to have 0 kW electric resistance backup capacity.
See Ekotrope’s guidance for modeling DFHPs here
Geothermal Heat Pump Water Heaters:
In REM/Rate, set the water heating equipment to "heat pump" rather than "ground source heat pump" and maintain the geoHPWH's EF rating.
Work-arounds require that the home's HERO Performance report be generated with the "true-to-life" equipment modeled. The file submitted for rebate payment should include the work-around modelling described above. Be sure to include a note in REM/Rate about the inclusion of work-arounds.
All equipment incentives must be submitted with a matching AHRI certificate and an invoice from the HVAC contractor that lists equipment size and efficiencies (builder purchase orders are not accepted). Prices may be redacted from invoices at the builder's discretion.
Quality Installation (QI) incentives require that a completed QI checklist be uploaded. QI is required for all 14 SEER ECM installations.