SL-90-07-1 -- Raised Floor Air Distribution - A Case Study PDF

Describes a raised-floor air distribution installed throughout a a three-storey 800 m² office building in Windsor, England, as a result of a comparison between underfloor and conventional overhead systems. States the selection of the type of floor outlet took into consideration the risk of draughts and cold feet and balanced these against supplying sufficient air to meet the peak cooling load. Twist outlets measuring 150 mm were selected with an airflow rate of 12 L/s at a supply temperature of 18degC. This supply temperature suited the 'free cooled' chilled water available but limited the supply air temperature difference. The effect of stratification was utilised to increase this difference, but not totally due to other restrictions. Two thirds of the air was exhausted via the floor, and great difficulty was encountered sealing the duct wall between site-constructed supply and extract plenums. States the system has proven draught-free and satisfactory in operation since July 1988.

KEYWORDS: Air distribution, case studies, UK, offices, elevated, floors, air flow, air conditioning, underfloor, performance, comfort, designing.