I got a comment for one of our project which in my opinion is not ccompatibe with ASHRAE. We do not have much time for the response, so I decided to ask about it here.
We modeled System Type 7 with some 3,9 and 10 if required. Main source of heat is Remote Hot Water from municipal grid.
"It is unclear how the hot-water design supply and return temperature diﬀerence (28 deg. C) has been determined for theBaseline model. If following Path 1. ASHRAE Standard 90.1-2010, Appendix G, the hot-water design supply and return temperature diﬀerence must be based on the actual hot-water loop conditions modeled in the Proposed model (which is 20 deg. C in this case)."
Appendix G states:
Hot-Water Supply Temperature (Systems 1, 5, and 7). Hot-water design supply temperature shall be modeled as 82°C and design return temperature as 54°C. " - because of that we modelled 28C.
I am confused now.