commercial service calculations

[DaveBowden]

I'm bidding a job for a pharmceutical distributor. General offices and areas to fill orders.
The building is just over 4600 sq feet. There is one 4500W water heater, 76 receptacles, and 72 2X4 3 lamp lay-in fixtures. There are also 4 a.c. systems. They are heat pumps (4600VA per compressor) with 10kW auxilliary heat strips.
My questions are:
1. Since this is not a dwelling unit, is there any derating available for the a.c. systems due to having 4 separately controlled units?
2. Is there any derating available for the heat pump strips ( 65% af auxilliary strips with heat pumps?
The engineer and I are disagreeing over the service calculations. It is single phase.

 

[bob]

Do you think the service the engineer specified is too large?
1. no
2. no

 

[DaveBowden]

The property owner is paying for the tenant build out. He doesn't want to spend any more than he has to.
The engineer included 48.05 kVA under the classification of "spare" in his load calculations.
He is in the process of recalculating it because he originnally thought it was going to be three phase.