Shimizu Corporation announced that it has developed a displacement air cleaning system that applies displacement air conditioning technology which offers superior performance in ventilation. This system was developed to contribute to higher clean room productivity and energy savings. This system blows clean cold air toward the clean room floor, replacing the air in the room that has been warmed by the internal heat generated by production equipment and other sources, thereby cooling the room and cleaning the work area. The chief characteristic of this system is that it does not require the installation of air conditioning equipment in the ceiling of the clean room so it can maximize use of the room height in a clean room, enabling installation of bigger production equipment with higher productivity. It can also provide steady ventilation at lower air volume circulation and provide tremendous energy savings. This system is intended for clean rooms in plants that manufacture electronic devices and other types of manufacturing that require a relatively low degree of cleanliness. The product life cycle in electronic device industry is becoming shorter and how to shorten the lead time needed to update a manufacturing line is a major issue. Meanwhile, increasingly larger production equipment is being installed in clean rooms to achieve higher productivity, and air conditioning equipment installed on the ceiling presents an obstacle that prevents new production equipment from being installed in some cases. A new clean room would need to be built in such cases, leading to a delay in equipment operation and this could result in loss of business opportunities. The company therefore developed a displacement air cleaning system in clean rooms as a new type of air conditioning system that offers superior energy savings and can make maximal use of ceiling space. This system has vents that blow clean cold air in the lower part of the walls and air exhaust vents from the room on the upper part of the walls. It is not necessary to have air conditioning equipment on the ceiling so this can raise the effective ceiling height by a minimum of one meter. Moreover, the clean cold air directed at the floor from the blower vents has a low wind speed and a different specific gravity than the air in the room. This causes thermal stratification as the clean air pools in the lower part of the room, which enables limiting the area to be air conditioned to the work area, up to around two meters in height. The heat generated by the production equipment and people also generates an updraft in the room, transporting the fine particulate matter that is floating in the work area to the top of the room, where it is exhausted through the exhaust vents. This reduces air circulation by about 30% compared to existing air conditioners that blow cold air from the ceiling and agitate all of the air in the room. Applying this system to the construction of new clean rooms in addition to existing clean rooms will enable the construction of low-cost facilities with lower ceiling height. Shimizu intends proceed with proposals that target application to the renovation of existing clean rooms and to new construction projects.