An HVAC&R system that includes a first pumping device configured to circulate a first volume of a first two-phase medium, a second pumping device configured to circulate a second volume of the first two-phase medium, a first plurality of secondary HVAC&R units, a second plurality of secondary HVAC&R units, a first primary HVAC&R unit, and a second primary HVAC&R unit. At least one of the first plurality of secondary HVAC&R units is operably coupled to the first pumping device. At least one of the second plurality of secondary HVAC&R units is operably coupled to the second pumping device. The first primary HVAC&R unit is operably coupled to at least one of the first plurality of secondary HVAC&R units and the first pumping device. The second primary HVAC&R unit is operably coupled to at least one of the second plurality of secondary HVAC&R units and the second pumping device.