An appliance includes an outer wrapper having a plurality of walls that define an external surface and an inner liner. A trim breaker seals the outer wrapper to the inner liner to define an insulation space. A vacuum port is disposed on the external surface of the outer wrapper. A channel is in fluid communication with the vacuum port and extends along at least one of the plurality of walls of the outer wrapper. An insulative material is disposed between the outer wrapper and the inner liner. A filter media is disposed along the channel such that air can be drawn from the insulation space past the filter media, into the channel, and through each vacuum port.