HVAC PVAV no change in fan energy consumption using demand controlled ventilation?

Hi LadybugTools forum, I’ve been running simulations looking at the difference between the default HVAC templates, and noticed something strange with the calculation of fan energy for PVAV and VAV systems.

When toggling demand controlled ventilation off and on or air side economizer off and on, there is almost no change in fan energy consumption - how can this be?

I would have thought this would have a dramatic increase in fan energy swapping to a CV system such as packaged single zone heat pump (PSZ-HP), could you shed some light on why this is happening?

note all simulations run as single ‘shoebox’ office building with same internal design conditions, only thing I changed was the system type, demand control toggle or airside economizer toggle, and i’m running Honeybee v1.4