Air conditioning assembly

An air conditioning assembly for an environmental chamber, the air conditioning assembly comprising:

• a suspended ceiling for suspending below a structural ceiling of the environmental chamber to create a plenum space therebetween, said suspended ceiling being configured to cover a substantially horizontal plane of the environmental chamber while leaving a first perimeter gap adjacent to a first wall of the environmental chamber, and a second perimeter gap adjacent to an opposing second wall of the environmental chamber;
• a substantially vertical wall for covering a vertical plane of the plenum space, the substantially vertical wall being disposed between the first and second walls;
• at least one fan within the plenum space, said at least one fan being configured to draw air from one side of the substantially vertical wall to the other side, and therefore configured to draw air from the environmental chamber and into the plenum space through the first perimeter gap, and to blow air from the plenum space and into the environmental chamber through the second perimeter gap;
• and
• at least one air conditioner in fluid communication with the at least one fan, configured to condition the air flow passing through said at least one fan;
• wherein the at least one air conditioner comprises an altitude simulator for changing the oxygen content of the air flow, and the first perimeter gap and the second perimeter gap are configured such that they span along substantially the entire edge of the suspended ceiling such that, in use, the air conditioning assembly is configured to create substantially laminar air flow throughout the environmental chamber.