Hello. I'm working late tonight and have come across something a little
strange. If someone could explain this to me, I'd appreciate it.

I am modeling a building with system type PVVT (heat pump). Indoor fan mode
during occupied hours is intermittent, night cycle control is enabled. All
other defaults from the design development wizard are intact.

I set up a parametric run to evaluate energy savings from demand control
ventilation, and... my energy use increases! Most of the increase is seen
in boiler energy for adding heat to the loop. I understand that the
ventilation air may need to be heated when the heat pump is not running, but
I wouldn't think that this would put such a load on the boiler, especially
because the overall energy energy needed to condition ventilation air should
be reduced.

Any light on this issue is appreciated.

Thanks,

~Karen~