Embodiments of a canister for a negative pressure wound therapy systems and methods for operating the systems are disclosed. In some embodiments, the canister includes a receptacle for receiving wound exudate. A filter stack is interposed between the receptacle and the pump assembly and provides a fluid flow path therebetween. The flow path is more easily navigable by gas than by liquid, thereby allowing the pump assembly to apply a negative pressure to the canister without aspirating wound exudate into filters housed within the filter stack.
