Is there a simple method for modeling a device that flows air at a specific delta T?

Similar to a convection heater, there would be an Inlet Volume Flow and an Outlet Volume Flow, with the outlet temperature dependant upon the temperature of the inlet. I'm not concerned with what's going on inside the device.

It would seem that this would be possible by creating a Dependency formula in the Boundary Condition's Thermodynamic Parameters, but this doesn't appear to be the case. Perhaps I'm overlooking something?

Thanks, Neil