Dear colleagues,

I wanted to see how Total Electricity and Total Natural Gas Consumption
(furnace) vary with various hvac system parameters. 9 parameters both on
cooling side and heating side were considered and I have varied each of
these parameters individually keeping others constant and observed how
Tot-Elec and Tot-Nat-Gas consumptions vary with them. The system under
study was a simple packaged single zone system with DX coils and a furnace
fueled by natural gas for Abbotsford (Canada) climate.

Surprisingly, when the supply fan efficiency alone was varied, increase in
efficiency resulted in increased consumption of total natural gas. Total
electricity variation was normal with fan efficiency. Also, increased CFM
resulted in reduced total natural gas, while I believe these results are
supposed to be in the other way.

Even after a lot of brainstorming, I could not figure out what is
happening and what is that I am missing.

I am attaching the excel file containing these data herewith. Sheet1 has
Total Natural Gas vs. Supply fan eff. data; and Sheet-2 has Tot-Nat vs.
CFM.

Please suggest/correct me on what I was missing here.

Thanks a lot in advance!

Venkata Ramakrishna P