Fan Silencers for Industrial Fan Noise Reduction
You’re probably not going to be looking for a lot of “peace and quiet” on the shop floor, but you and your employees and colleagues are working there for hours at a time. You might even need to have a conversation, or just hear yourself think. Industrial fans can add to the noise level, but fortunately, you can accomplish industrial fan noise reduction by way of a fan silencer.
Calculating Noise Levels
Without getting too technical here, there are three units of measure related to industrial fan noise levels, including:
- Fan Sound Pressure (Lp)
- Fan Sound Power (Lw)
- Decibels (intensity of sound (dB))
The Air Movement and Control Association (AMCA) provides testing standards for fan Lw levels, which are derived through calculations best done by your application engineer and/or an acoustical engineer. According to a June 2017 article in Processing Magazine, typical industrial noise levels from a fan application can range from about 70-120 dB. You will also find an in-depth discussion of fan sound measurement and calculation in the article, titled Understanding Fan Acoustics.
Your fan manufacturer should be able to give you a strong start by providing you with the expected sound power and pressure levels their fan will deliver based on its surrounding conditions. Then, based on your application, we will often recommend a fan silencer to handle any application-specific industrial fan noise reduction requirements. Put simply, we can hear the difference.
Safety: How Loud is Too Loud?
Each person has a different interpretation and level of tolerance for excessive noise. You might not be satisfied until your music is “turned up to eleven” while your friend might be blasted out of the room at five.
But, according to the Occupational Health & Safety Administration (OSHA), there are some noise level thresholds that employers must listen for, measure, adjust, protect and/or moderate based on length of exposure.
According to OSHA’s website, “OSHA has established permissible noise exposure limits to help avoid the standard threshold shifts in working. If the noise level exceeds 85 dBA on a time-weighted average, a hearing conservation program is required. The actual exposure limits are given in Table 1. (Review OSHA’s occupational noise exposure 1910.95 for a full explanation.)
For an interesting and fun way to think about and compare sound levels, check out the infographic in this World’s Loudest Noises article from The Air Conditioning Company. Be prepared – it is noisy!
Fan Silencer for Industrial Fan Noise Reduction
An open fan inlet or outlet is a common culprit behind excessive noise levels. An inlet and/or outlet silencer can adequately reduce the noise levels for many of these applications. There are other factors and solutions to consider, but we will address those in future posts.
Factors in selecting inlet fan silencers include the kind of fan (centrifugal or axial), the configuration of your ductwork, the allowable drop in pressure, and of course, how much industrial fan noise reduction is required. At the discharge of the fan, you’ll need to also consider velocity, pressure and temperature control, as well as material handling requirements and corrosion resistance.
Once you assess all of these factors, you will be ready to select the optimal fan silencer for industrial fan noise reduction.
Hear it from the Application Engineer
Senior Application Engineer Chet White provides a demo in this 20-second video.
When you’re ready to start your project, reach out and connect with one of our application engineers to discuss the details of your specification.
Related Content on Industrial Fan Applications
There are many factors to consider in every industrial fan application. We’ve seen it all. Here are several other articles that might be of interest as you think about your application:
- FAN SELECTION: HOW TO TELL US WHAT YOU NEED
- INLET BOX: DO YOU NEED ONE IN YOUR CENTRIFUGAL FAN APPLICATION?
- INLET AIR DENSITY CALCULATIONS FOR CENTRIFUGAL FAN APPLICATIONS
- CENTRIFUGAL FAN DISCHARGE: DETERMINING THE OPTIMUM POSITION
- PROCESS OF ELIMINATION: FAN VIBRATION ISOLATION CONSIDERATIONS