Fan noise is oftentimes overlooked when choosing a fan. Fan noise will vary by fan type, flow rate, pressure and fan efficiency. Other factors such as walls, floors, ceilings and other equipment will have an effect on noise reflection and absorption to varying degrees as well. Here are a few tips you will want to consider and understand before selecting a fan:
OSHA Exposure Limit
From a safety standpoint, OSHA’s (Occupational Safety & Health Administration) permissible exposure limit is 90 dBA based on a time-weighted average over an 8-hour day. Similarly, NIOSH (National Institute for Occupational Safety & Health) recommends limiting the 8-hour exposure to less than 85 dBA. It’s also important to know that decibels are measured on a logarithmic scale, which means that a small change in the # of decibels will result in a huge change in the amount of noise and potential damage to a person’s ear. For example, a thunderclap measured at 120 dBA can be over 30 times as loud as the noise at 70 dBA.
Understanding Decibel Levels
The ear is a sound pressure receptor. To get a feeling for decibels, look at the table below which gives values for the sound pressure levels of common sounds in our environment. When making noise comparisons, keep in mind that noise measured at 120 dBA for an extended period of time can cause pain or possible hearing loss.
|Outdoor/Indoor Noise||Sound Pressure Decibel Level (dBA)|
|Jet aircraft at 50 ft. away||140|
|Threshold of pain||130|
|Threshold of discomfort||120|
|Chainsaw at 3 ft.||110|
|Disco at 3 ft. from speaker||100|
|Gas lawn mower at 3 ft.||90|
|Diesel truck at 50 ft. at 50 mph||80|
|Vacuum Cleaner at 10 ft.||75|
|Normal Speech at 3 ft.||70|
|Heavy traffic at 300 ft.||65|
|Large Business Office||55 *|
* Americraft industrial fans are NOT well suited for an office environment.
The Americraft fan dBA levels can range anywhere from the low 70’s to high 90’s at 10 ft. If noise is an issue, consider using a larger fan at a lower speed (rpm) or a belt-driven fan. Feel free to contact our office if you have any questions about a specific model. We would be happy to help you in all aspects of your air moving requirements.