Techniques for cooling in a data center are provided. In one aspect a computer equipment rack is provided comprising one or more air inlets; one or more exhaust outlets, and one or more of: an air inlet duct mounted to the computer equipment rack surrounding at least a portion of the air inlets, the air inlet duct having a lateral dimension that approximates a lateral dimension of the computer equipment rack and a length that is less than a length of the computer equipment rack, and an air exhaust duct mounted to the computer equipment rack surrounding at least a portion of the exhaust outlets, the air exhaust duct having a lateral dimension that approximates the lateral dimension of the computer equipment rack and a length that is less than the length of the computer equipment rack.