I have a heating only space with forced ventilation unit heaters. I've
tried modeling this space with and without baseboard heaters. When I
add baseboard heaters with the unit heaters, my annual heating
consumption triples. I was not expecting this to have a drastic impact
on the natural gas usage. Does this mean that my model without the base
board heaters is not meeting all of the heating loads? I've checked the
equipment size against the peak demand and it seems adequate and the AHU
schedule does not indicate any hours outside the equipment capacity.
What is causing the apparent change in load between these two models?

-Rod