Customer was reburishing his building and asked us to add VAV boxes to all his rooms. We put in 101 vav's and took control of 3 AHU's adding VFD's. He didn't want to pay the extra cost to get wall sensors with occupancy buttons and add scheduling. He also didn't want us to take over 12 FPBs, the pumps, the chiller, the other 2 AHU's, and all 8 split-systems.
3 months after we finished the install the customer asked us to come back and put controls on 4 splits and the other two air handlers. I asked him what changed his mind about adding the other equipment. He showed me his electric bill for the month.
His energy use from last year to this year dropped by almost 40,000Kw.