Duct-mounted or suspended fans vary in size, configuration, and horsepower. These variables, coupled with location and application, will help determine the correct isolation and restraint solution. Fans will often require a solution for both airborne and structure-borne noise.

Neoprene Hangers or Spring Hangers with Neoprene and Bottom Cup provide vibration isolation for suspended equipment. The neoprene element isolates from high frequency vibration and eliminates steel-to-steel contact.

Neoprene coated up-stop washer provided for seismic applications to protect against damage.

Utilizing the uniquely designed BulletLockTM securing mechanism, the BulletBraceTM is the fastest adjustable cable restraint system on the market.

Custom designed restraint solutions to be used for various structural types, including BulletClampTM. Other difficult structures to be noted are trusses, pan deck, thin concrete deck.

Design Considerations

Structure-Borne Vibration

Problem: Suspended fans can transmit vibration through the rod hangers into the structure that can create serious noise problems.

Solution: Spring hangers. If space will allow, SHRB with neoprene element under spring and separating structural attachment is ideal.

Seismic Requirements

Problem: Horizontal and vertical forces applied at the center-of-gravity of the unit require proper design of the attachment of the unit and/or vibration isolators to the structure.

Solution: Properly designed cable or solid restraint system to be installed. Cable system required when unit is isolated.

Problem: Net uplift forces on units with spring hangers can cause damage and lead to failure of spring hangers.

Solution: Spring hangers with up stop limit washers to be used.

Problem: Forces are determined by a number of factors including: project location, site class, risk category, component importance factor and equipment location equipment relative to the overall height of the building.

Solution: Certified anchorage calculations must be submitted to verify loading conditions are met for each piece of equipment.

Problem: Structural attachment may have limited capacity or be difficult to attach.

Solution: Custom designed restraints to be used for various structural types, including BulletClamp. Other difficult structures to be noted: trusses, pan deck, thin concrete deck.

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