Centrifugal Fan Anti-Vibration Pad – Vibration Isolation Mounts for Industrial Fan Bases

Component Overview

Every centrifugal fan generates vibration or oscillating force when running at operating speed. This constant vibration, caused by slight imbalances in the impeller, air pressure and drive-train loads, travels through the fan's base and hits its main structure. Without proper insulation between the fan and the floor, its vibrations can travel through the concrete to the building's structure, pipework and other sensitive machinery. As a result, the building's structure gradually weakens, annoying noise pollution spreads in the surrounding area and the life of the equipment connected to the fan decreases very quickly. A Centrifugal Fan Anti-Vibration Pad is a resilient material such as rubber, neoprene or steel springs that is placed between the fan base and the floor. It works on a simple principle: the natural frequency of the pad is kept well below the operating frequency of the fan. As a result, the vibration gets stuck in the pedal instead of spreading throughout the structure.

This is in accordance with AMCA International and ASHRAE technical regulations that the isolator natural frequency should be 40% or less than the minimum operating frequency of the fan. Also, when installation on the upper floor or roof, another strict criterion must be followed to minimize floor resonance, the static deflection of the isolator must be at least 10 times greater than the deflection of the supporting floor itself. The exact amount of static deflection required of the isolator is directly proportional to the fan's RPM. For example:

960 to 1,450 RPM: Fans at this speed require spring isolators with static deflection of ~12 to 25 mm.

Above 1,450 RPM: If the fan speed is higher than this, a rubber or neoprene pad with ~6~12 mm deflection is sufficient.

Below 600 RPM: Low-speed fans require a lot of isolation to handle vibration. Therefore, ~40-50 mm high-deflection spring isolators are required for these fans.

Rubber anti-vibration pads and rubber-cork composite pads are a great choice for mounting small to medium-sized fans on ground floors or in basements. The main advantage is that they do not need any height adjustment and can very efficiently block high-frequency noise or vibrations at a reasonably modest cost. For medium to large fans, open steel spring isolators are the normal choice. Due to their high static deflection, the required low natural frequency can be easily achieved at normal fan operating speeds. But for roof installations, earthquake-prone areas, or areas exposed to high winds, restrained spring isolators-IBC compliant-must be used. The inbuilt limit stop prevents over travel and guarantees 100% isolation performance. The structure or floor on which the fan will be installed must be at least 10 times stronger than the isolator. If the isolator deflects as much as it lowers and the floor deflects the same amount, the whole isolation system will fail or become useless. Each Centrifugal Fan Anti-Vibration Pad is therefore selected based on the weight of the fan, the operating RPM and the type of floor on which it is to be installed. This can easily ensure correct static deflection and maximum isolation efficiency.

Primary Industrial Uses

Combustion & Burner Industry

Oil, Gas & Petrochemical Industry

Automotive & Painting Industry

Marine & Shipbuilding Industry

Tobacco Industry

Agriculture Industry

Textile Industry

Glass Manufacturing Industry

Pulp & Paper Industry

Food & Beverage Industry

Ceramics & Brick Industry

Packaging Industry

Compatible With

Y-Series, X-Series, W-Series Centrifugal Fans

Rubber and neoprene pad options for standard installations.

Induced Draft and Forced Draft Fans

Heavy-duty spring isolator options for large base frames.

Belt Drive Centrifugal Fans

Spring isolators with leveling adjustment for drive alignment maintenance.

Rooftop and Upper-Floor Fan Installations

Restrained spring isolators; IBC seismic compliance available.

All centrifugal fan types

Selection by fan weight (kg), operating RPM, and floor type.

Available Types

Rubber anti-vibration pad	ground floor / basement; small/light fans; high-frequency noise break
Rubber-cork composite pad	light to medium duty; improved damping over pure rubber
Neoprene mount	HVAC and AHU applications; 5~12 mm deflection
Open steel spring isolator	medium/large fans; 12~50 mm deflection; height adjustable
Restrained spring isolator	IBC compliant - rooftop; seismic zone; wind-load rated

Type	Static Deflection	Best Application
Rubber Anti-Vibration Pad	3~6 mm	Small/light fans; ground floor or basement installations
Rubber-Cork Composite Pad	4~8 mm	Light to medium duty fans; improved damping over pure rubber
Neoprene Mount	5~12 mm	HVAC and AHU applications; non-critical floor installations
Open Steel Spring Isolator	12~50 mm	Medium to large industrial fans; any floor level
Restrained Spring Isolator (IBC)	25~50 mm	Rooftop fans; seismic zones; wind-load rated installations

To order: Contact us with your fan model, total fan + motor weight (kg), operating RPM, and installation floor type (ground slab / upper floor / rooftop) for correct isolator selection.

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