New Office Remodel = poorly insulated??

A year and a half ago, I purchased a 35 y.o. building, gutted and remodeled the entire structure for a new professional office (dental). The original walls, sub-floors, foundation and half the roof were retained. Everything else was built new: insulation, electrical, mechanical, water/sewer, etc.

During the first year, the following problems have popped up: The A/C units can't keep up when the outside air temp rises above 80 F. It is important to maintain about 72 F because of a number of procedures in our dental laboratory and when outside air gets above 80, the temp rises inside. Usually peaks at about 78F. Electrical costs are also way above the norm for a 2800 sq ft building.

I hired an engineer who did the math, equipment load, insulation R-values, tonnage of the two A/C units.... and everything should "be working just fine." The contractor, the mechanical company and the engineer (who also works for them on large projects) all state everything is OK..... Meanwhile, we can't keep the temperature down to a comfortable and necessary range at any expense. The systems are just not performing properly.... even if they are brand new. I suspect significantly inadequate insulation and air leakage.

What should I do? Who can I turn to to get proper, valid advice about our situation. Are there independent engineers who have a "green" perspective to aid in determining a solution to our dilemma ?

Thanks for any input you may have.

Geoff
Augusta, GA