Computer cooling

The description relates to cooling electronic components, such as computing devices. One example includes a rack defining a volume and multiple sealed chassis modules removably fluidly coupled to a two-phase condenser tank via a vapor coupler and a liquid coupler. Individual sealed chassis modules can contain one or more electronic components immersed in two-phase coolant that when heated by operation of the electronic components experiences a phase change from a liquid phase to a gas phase and travels to the two-phase condenser tank via the vapor coupler and is cooled in the two-phase condenser tank until experiencing a phase change back into the liquid phase. Individual sealed chassis modules can be decoupled from the two-phase condenser tank without releasing two-phase coolant and an entirety of the multiple sealed chassis modules and the condenser tank are contained in the volume of the rack.