All,

I am trying to settle a dispute within our office.

Our design utilizes Fulton Condensing Boilers with a design Return water
temperature of 160 deg. F and an outdoor air reset schedule.

Our dispute is what to enter as the HIR for the boiler. The boiler is
86.5% efficient at 100% fire and 160 deg. F return water temperature,
and 96% efficient at 100% fire and 80 deg F.

It is my understanding from everything I have read that the HIR needs to
be 1.156 which would be 86.5% efficient. Is this correct? Also how
does the default e-quest HIR-fPLR curve function?

Thanks for any help.

Steven C. Tobin Jr., P.E.