A computer system is described of the kind having a frame and a plurality of server unit subassemblies that are insertable into the frame. Each server unit subassembly has a chassis component which engages with a frame component on the frame. Heat can transfer from the chassis component to the frame component, but the server unit subassembly can still be moved out of the frame. In one embodiment, an air duct is located over a plurality of the frame components. Heat transfers from the frame components to air flowing through the duct. A modified capillary pumped loop is used to transfer heat from a processor of the server unit subassembly to thermal components on the frame.