Raised access floors

In some cases, raised floor voids can be used as a plenum for air-conditioning systems. In such cases there will be an air pressure differential between the air within the plenum and that within the office itself. While conditioned air is usually distributed via flexible ducts and special nozzles in selected floor tiles, excessive air leakage through panel joints can render the system inefficient, so special attention needs to be given to panel joints. At one level, neoprene tapes around the edges of tiles may be sufficient but. in areas that are likely to be accessed regularly, wear and damage to the tapes could be a problem. Alternatively, stringers fitted with gasket seals can be fixed to the pedestals so as to provide an effective seal around the entire perimeter of the tile.

Airtightness testing is usual as part of the commissioning of the building prior to completion. While the manufacturer may provide air leakage data based on laboratory tests, field tests of the as-installed floor would give a better indication of actual performance and would assist in the diagnosis of additional leaks through service penetrations, cut perimeter tiles, etc.