Threshold / Sampled Ratings

Ekotrope and RESNET support Threshold HERS Ratings.  Threshold ratings allow for greater HERS score consistency across a variety of homes by allowing "threshold" values to be set, which are used in the simulation to determine the HERS Rating, but the field test results are allowed to differ from the threshold values so long as they are the same or lower.  

In Ekotrope there is an option in the Project Info screen to select a Threshold or Sampled Rating type.  If the one of these rating types are selected, then Threshold / Sampled should be selected for Infiltration and tested Forced Air distribution systems.

There are two types of ratings that should use the Threshold / Sampled selections for Infiltration and Forced Air distribution

1. Confirmed Threshold Ratings.  These are ratings where every home is tested, but the Threshold value is used for the HERS simulation rather than the tested value.  For these ratings, the Field Tested boxes for infiltration and distribution systems should be populated with the field test values.  However, according to RESNET, it is acceptable to leave the field test value at 0 to indicate that the final model has not been updated with the actual field test value.
2. Sampled Ratings.  These are ratings where only certain units are field tested, and all the units use a threshold value for HERS simulation.  For these ratings, the Field Tested boxes for infiltration and distribution systems should be populated for tested units only.  Un-tested units should have 0 in the Field Test boxes.