The Department of Energy published an analysis of the energy savings for the ASHRAE 90.1-2010 standard over the 90.1-2004 version.
The work was done by PNNL using EnergyPlus.
I was examining the results for the 22,500 square foot retail strip mall.
I carefully inputted this building into eQUEST (...I say carefully, to include schedules etcetera, but I didn't shoot for perfection!).
Everything lines up fairly close for the annual energy use in Btus for the different categories.....except the fan energy used (per eQUEST Report BEPS Building Energy Performance). The "Vent Fans" usage is three times as much in EnergyPlus when compared to eQUEST. This is a fairly simple building with Packaged Rooftop units with gas furnaces.
I've noticed this before on occasion when I try to input EnergyPlus modeled buildings into eQUEST, although I can't recall the exact details of other instances.
Does EnergyPlus account for fan usage in a different manner than eQUEST? Perhaps part of the "Space Heating" in eQUEST is dropped into the fan energy usage category in EnergyPlus?
Any thoughts are appreciated.
Mark

Mark Campion