Vibration isolators for FCUs, chillers, pumps, AHUs, and rooftop plant.

An FCU is ceiling-suspended, so the isolator sits in the hanger rod rather than under the unit and is selected on the load carried at each hanger point, not the total unit weight. Rubber hangers cover light point loads on small cassette and ducted units; spring hangers are used where the load is higher, the drop rod is long, or the ceiling void sits above an acoustically sensitive space such as a bedroom, ward, or meeting room. The first few pipe and duct supports leading away from the unit should also be isolated so vibration does not bypass the hangers.

A grommet or rubber bush at the fixing only breaks metal-to-metal contact and offers very little deflection, so it does little for the low-frequency vibration an FCU fan produces. A rubber hanger fitted into the drop rod gives measurable deflection at light point loads, and a spring hanger is used where more deflection is required. Treat a grommet as a supplement to a hanger isolator rather than a replacement for one.

The most useful information is equipment weight, operating RPM, number of mounting points, floor type, pipe connection layout, and any specified deflection or isolation efficiency.

Spring mounts are normally used for heavier or lower-speed rotating equipment where higher deflection is needed. Neoprene pads are suitable for smaller equipment, higher-speed machines, or slab-on-grade locations with lower isolation demand.

No. Flexible connectors help prevent vibration from transferring into pipework, but the equipment itself still needs suitable mounts, pads, or an inertia base depending on load and RPM.