vice versa and the ceiling tiles be changed to increase or decrease the area of high density filtered air inlets floor 20 is designed and constructed to be a load bearing floor the floor is designed so that equipment can be placed directly on the perforated floor at any location within the clean room 90 regardless of the size of the clean room because equipment can be placed and supported anywhere on the perforated floor equipment can be moved into and out of the clean room at will and can be placed in any location within the clean room moving equipment into or about clean room 90 does not require the dismantling of a raised floor nor the assembly or moving of a costly support platform upon which the equipment must rest equipment can easily be moved into or out of clean room 90 on an air palette without compromising the cleanliness of the clean room an air palette can easily move across the perforated floor by placing thin sheets of air impervious material such as thin sheets of plastic or metal over the floor grates as a temporary measure while the air palette passes over the grates in addition all facilities lines such as gas lines chemical lines power lines and the like can be routed from the equipment through the nearest opening 22 to the facilities room below this is in contrast to the conventional raised floor clean room in which facilities lines are routed underneath the raised floor thus in accordance with the invention facilities lines need not be routed across the floor and thus need not impede the movement of equipment across the floor in a preferred method the clean room in accordance with the invention is constructed as follows the facilities room 30.