Rebecca,

The additional pressure drop through the heat exchanger and its filters has an electrical energy penalty that can sometimes (actually, quite often) cancel out cooling energy savings. I suggest checking these pressure drops to make sure they are realistic. I would also see if the air could be allowed to bypass the heat exchanger when not needed, such as for economizer operation, to reduce the number of hours that the extra pressure drop is experienced.

Keith Swartz, P.E., LEED AP