A rack arrangement for a data center includes at least one row of racks including a plurality of computer racks and an air handler rack. Each computer rack includes a computer rack frame including a housing unit for housing computer equipment. The air handler rack includes an air handler rack frame, a heat exchanger and at least one fan. The at least one fan is configured for pulling air into the air handler rack via an air inlet side and discharging air via an air outlet side of the air handler rack, directing air through the heat exchanger. An air inlet side of any one of the computer racks and the air outlet side of the air handler rack are on a cold aisle side of the at least one row of racks. At least one selected rack is stacked atop the air handler rack.