Something doesnt sound right. What if it is a hot year, what if with
with the new system you run it longer and cooler to get the utilities
way up. How does he know you wont open your windows to get your rebate
and upgrade.

He should be checked out with allot of refrences and Court records to
see if anyone has brought suit. How long has he been in business, under
Any name.

How old is your unit, what seer, did it cool good, to much or to
little. Did a load calculation get done.

What is your new unit and seer.

You could easily crank the unit and open windows to not get an 30%
savings, How will he know, then what does he do?

If you are getting a very high seer unit and your old unit has a very
low seer savings could be
50 - 75 % not 30 %