Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Based on internet research it seems like gas-fired instantaneous (tankless) water heaters have UEFs up to 0.82.
In ResStock the measure argument water_heater_efficiency_type = EnergyFactor, so I converted a UEF of 0.82 to EF using RESNET's 2017 guidelines (below).
https://www.resnet.us/wp-content/uploads/RESNET-EF-Calculator-2017.xlsx
I assume a Propane Tankless model would fall under "Instantaneous Gas-Fired Water Heater," and therefore UEF = EF.
Since the EF for the Propane Tankless model in ResStock is 0.82, it's reasonable to conclude it represents non-condensing equipment, but it would be great to get confirmation from the ResStock team.
