Good afternoon all,

I am wondering if anyone has found a good way to model condensing boilers with Trace. From discussions with Trane staff it appears that a new curve could be produced, although I did not receive much guidance from them.

I think one way to do it would be to create multiple boiler plants, the multiple boilers provide a way to do a sort of hot water reset temperature based on OSA.

My thought is that I can create a linear hot water supply water reset based on OSA temperature (using appendix G requirements) from 120?F @ 50?F to 180?F @ 20?F, with each boiler based on a 10?F OSA increment. From these temperature setpoints I would assume that the;

Heating Hot Water return temp = Heating Supply - 20?F (Temp rise from Aerco curve)

I would then be able input the corresponding efficiency at that point for the boiler.

Has anyone had any experience with this? Any advice would be greatly appreciated.

Thanks and have a great day,

Josh