A door assembly comprising: a first body having an internal first cavity; a second body having an internal second cavity and including a channel; a hinge element projecting from the first body, the hinge element having an internal hinge channel in fluid connection with the first cavity; and a pin projecting from the second body, the pin extending into part of the hinge channel to pivotably secure the hinge element and second body to one another such that the hinge channel aligns with the channel in the second body and forms a fluid connection between the first and second cavities adapted to receive a conduit extending from inside the first cavity to inside the second cavity via the hinge channel, wherein either of the first and second bodies (1, 2) is a door, and wherein the second cavity is defined by a single hollow extrusion comprised in the second body, the channel in the second body being an extruded channel defined by and formed within the cross-section of said extrusion, characterised in that: the extruded channel is interrupted by an opening into which the hinge element projects so that the hinge channel and the extruded channel align with one another to form a vertical shaft; a thread is tapped along the extruded channel at an end of the extrusion, the pin having a corresponding threaded portion that engages with the tapped thread when the pin is inserted into said end of the extrusion and along the extruded channel to support the hinge element; and at least a portion of the hinge channel is substantially T-shaped so that the conduit is receivable to extend from inside the first cavity to inside the second cavity via part of the hinge channel and the pin extends into the other part of the hinge channel. a first body having an internal first cavity; a second body having an internal second cavity and including a channel; a hinge element projecting from the first body, the hinge element having an internal hinge channel in fluid connection with the first cavity; and a pin projecting from the second body, the pin extending into part of the hinge channel to pivotably secure the hinge element and second body to one another such that the hinge channel aligns with the channel in the second body and forms a fluid connection between the first and second cavities adapted to receive a conduit extending from inside the first cavity to inside the second cavity via the hinge channel, wherein either of the first and second bodies (1, 2) is a door, and wherein the second cavity is defined by a single hollow extrusion comprised in the second body, the channel in the second body being an extruded channel defined by and formed within the cross-section of said extrusion, characterised in that: the extruded channel is interrupted by an opening into which the hinge element projects so that the hinge channel and the extruded channel align with one another to form a vertical shaft; a thread is tapped along the extruded channel at an end of the extrusion, the pin having a corresponding threaded portion that engages with the tapped thread when the pin is inserted into said end of the extrusion and along the extruded channel to support the hinge element; and at least a portion of the hinge channel is substantially T-shaped so that the conduit is receivable to extend from inside the first cavity to inside the second cavity via part of the hinge channel and the pin extends into the other part of the hinge channel. the extruded channel is interrupted by an opening into which the hinge element projects so that the hinge channel and the extruded channel align with one another to form a vertical shaft; a thread is tapped along the extruded channel at an end of the extrusion, the pin having a corresponding threaded portion that engages with the tapped thread when the pin is inserted into said end of the extrusion and along the extruded channel to support the hinge element; and at least a portion of the hinge channel is substantially T-shaped so that the conduit is receivable to extend from inside the first cavity to inside the second cavity via part of the hinge channel and the pin extends into the other part of the hinge channel.