Entering a heat exchanger into ISBEM

[tobyB]

I am using the standard iSEBM software and have a new build which is to have a Biomass boiler situated externally to the actual building which is providing heat to a heat exchanger within the buildings plant room, which is then to provide underfloor heating.
The same heat exchanger is to also provide heat to an Air Handling Unit.
At present I have entered the AHU under a single duct VAV with LTHW Boiler as the heat source and Biomass as the fuel type.
The Underfloor heating is currently entered as Central heating using water; floor heating with LTHW Boiler as the heat source and Biomass as the Fuel type.
Is this acceptable or should I request the Heat Exchanger efficiency and input the systems differently?

Many thanks in advance for any assistance