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Three ways to reduce fan noise


May 1, 2020

Whether it’s to enhance driver comfort or comply with increasing emissions regulations, reducing fan noise has become one of the most important considerations when designing engines for trucks, construction machinery, mining equipment, agricultural tractors, generators and more.

Here are three ways to make it happen:

1. Spec a larger fan and run it a lower speed.

It’s no secret the fan can be the largest source of engine noise in an application. The faster it’s turned, the louder it is. So if there’s room for a larger fan — which by itself can facilitate more airflow — you can spec it into your engine design and spin it at fewer RPMs.

2. Pair the fan with a variable-speed drive.

Using the latest engine cooling technology, variable-speed drive delivers cooling only when needed, and only as much as is needed.

How? By using a pulse-width modulation signal derived via the inputs from the engine’s ECU. This signal actuates an internal valve, controlling the clutch, and allowing more precise cooling for systems such as the hydraulic oil circuit, air conditioning unit, and of course, the engine coolant.

When cooling is optimized, the fan doesn’t spin any faster than needed, and only operates at top speed when necessary — thus resulting in lower decibel levels.

Horton’s LCX series uses viscous technology to achieve this.

3. Choose a fan designed to emit less noise.

This is where the different customization options for engine cooling fans can come in handy. By tweaking factors such as material, blade count, diameter and blade shape, engineers can manipulate how much airflow passes through to the engine. The right balance of cooling ensures under-hood components stay safe from temperature swings — all while eliminating unnecessary noise.

[RELATED: Noise a central concern among manufacturers at Conexpo/Con-Agg 2020]

Taking these steps can help original equipment manufacturers align with policies such as the European Union’s Outdoor Noise Directive. The United States’ Occupational Safety and Health Administration is expected to push for similar legislation in the coming years.

With the right cooling system in place, OEMs can be more than ready.