I am doing a model for a two story office building with the windows
making up approximately 30% of the building's exterior. My goal is to
find what type of energy savings the owner can expect by replacing all
the existing single pane windows with double pane, low e windows. When I
change the window type to a double pane low-e window I am seeing savings
that are very small, around 3% of the total building kWh.

For reference, the buildings HVAC system consists of two air handlers
(one per floor) ducted to a VAV system with hot water reheat.

Has anyone else tried to do this type of comparison and if so what type
of energy savings did you find? I have attached my model pd2 and inp
files for reference. Thanks in advance for any information.

Brett West