13.10 Connecting the unit to air ducts
FLEXIBLE JOINT
GENERAL RULES
For a correct installation of the ductwork it is recommended to:
•
design the duct so that the air speed never exceeds 4-5 m/s, for the purpose of noise containment;
•
provide suitable brackets to support the ducting to prevent their weight from bearing on the unit;
•
always use a flexible joint between the unit and the ductwork;
•
provide an electrical earth cable to bridge the flexible joint, to ensure the duct and the unit are electrically equipotential;
•
before bends and branches, provide a straight duct with a length equal to at least 2.5 times the diameter of the duct to
avoid drops in fan performance.
DUCT
Fixing of air ducts
EN
35