There are many things to consider when choosing a fan or blower. In this article, we will discuss features such as Reactive chamber-type silencers, flexible coupling, and CFM rating. Additionally, we will discuss the differences between the two types of noise. After reading this article, you should be able to determine which one is right for you. But first, let’s look at the fundamentals of fan noise.
Reactive chamber-type silencers
The pitch line velocity (PLV) is a criterion for determining the correct silencer type. The higher the rotary speed and gear diameter, the greater the PLV. Normally, the PLV is calculated as the ratio of the rotary speed to the gear diameter and is expressed in feet per minute. In many cases, the PLV is critical to the reduction of blower noise, as the blower will generate objectionable high frequency noise, and will cause shell ringing or tank hammer. This means that a combination chamber-type silencer is necessary.
The lobe passing frequency of a reactive chamber is approximately 40 to 50 dB. This frequency is the range of frequencies for which the silencer should be used. A reactive chamber is designed with multiple small tubes connected by a large chamber. The noise produced by the blower or fan passes through each tube, reflecting back toward the source at the junction. The amount of transmission loss is proportional to the lobe passing frequency of the device.
The most effective way to reduce blower vs fan noise is to install a high-pressure, reinforced flexible coupling between the fan and the pipe ducts. Generally, these couplings should be installed three to five diameters away from the blower to reduce transmission losses. However, there is a downside: flexible couplings can also cause major acoustical leaks. However, because transmission loss through a flexible coupling is so low compared to a heavy-walled pipe, the problem can be solved by wrapping the coupling area with dense foam.
Regardless of the type of coupling, you need to ensure that it will meet your requirements for air handling and noise. Most manufacturing and industrial departments use a combination of blowers and fans for their air-handling needs. However, the most important thing to consider is the amount of noise produced by each. The more noise your fans generate, the higher your operating costs are. That’s why it’s important to understand the difference between these two types of air-handling units.
To find out which type of air circulation fan is best for your needs, you must first understand the difference between CFM and dB. In short, CFM stands for Cubic Feet per Minute, and refers to the amount of air that a fan can move in a minute. Higher CFMs mean more air movement, and consequently more noise. Both types of air movement fans can cause noise, and the quality of the fan and its overall design can affect its noise level. Another factor affecting fan noise is the speed settings. The faster the fan, the more air it will move and the higher the noise level.
Air flow rates are measured in cubic feet per minute (CFM) and cubic meters per hour (M3/Hr). This measurement is equivalent to the actual flow of air through a given fan, but the difference between CFM and dB is more apparent with blowers. The difference between CFM and dB is not so much a matter of style, but of function. For example, a high-end fan needs to move more air in four or more cases.
Blowers and fans produce very different levels of noise, but both types move air at a higher pressure. This means that there is no direct comparison between blowers and fans. However, you can use this information to find out what features you should look for in each type. Below we discuss the different factors that can affect the noise produced by these two types of fans. Depending on your needs, you may want to look for a fan with higher CFM and a lower noise rating.