I am modeling a 50,000 sf college cafeteria. The campus central plant boiler will provide steam to the cafeteria through a utility tunnel at basement level. Inside the basement, steam will be passed through a shell and tube heat exchanger to provide heat to the building hot water loop, as well as provide heating as needed in the condenser water loop via a direct steam injection tank and the SHW loop via a steam injection tank.
 
Energy Plus 8.5 has a steam boiler component with associated piping, steam traps, condensate pumps, and steam-to-air coil components. It does not currently support a steam-to-water heat exchanger or steam injection tank components. The available heat exchanger objects are for plant hydronic fluids only. The shell and tube heat exchanger will have an efficiency loss, while the direct steam injection tanks have no process loss (all energy in the steam heats the water) but do have tank losses. Since I can't model the system directly, I'm looking for suggested work-arounds. Could this system be modeled as district hot water system instead? Assuming a representative heat loss for the three steam components could be estimated, could that factor be applied to the district hot water system energy use to provide an adjusted district heat use? The same factor would be applied to the Baseline model output, assuming we use Addendum ai, G3.1.1.3.1, Purchased Heat Only.