Book - School of Science and Technology

424 Air distributionVelocity profiles:straightTwistFloor outletDirt basket(hit and miss damperoptional)Duct connectingcylinder (optional)Figure 15.23 Typical floor outlets (Krantz)of outlet is about 12 litre/s, and the supply temperature should not be lower than 5 K belowthe occupied zone temperature, and less in the case of displacement ventilation. Outletsshould be positioned clear of furniture and not closer than 1 m to the nearest work station.For computer room applications, where underfloor distribution is employed, the outletsnormally take the form of a 600 mm 600 mm floor plate either perforated or with a fixedlinear grille over the face; both types may be fitted with opposed blade regulating dampers.The volume handled by a 600 mm square plate would be of the order of 200±300 litre/s.Desk-top outletsThere are many designs for these devices, some of which are shown in Figure 15.24, andthey are usually used in conjunction with a floor distribution system. The purpose ofdesktop terminals is to provide occupants with considerable control over their immediatemicro-climate. In practice, the air flow quantity supplied in this fashion would be limitedto about 14 litre/s. Similar devices may be used in other applications, such as at the rear oftheatre seating.