PS: The dB readings were bouncing around between 16 and 22 mostly, and higher than that breathing normally. I do not have any screengrab software on my phone (I run it with minimal software and maximum restrictions), what screengrab software would you recommend for Android that is free and would be suitable for this App. My final problem was that I used the built in option and e-mailed myself what I thought would be a screengrab, it sent me a URL for the software □♂️ The second is that I had two PC's on, I turned off the noisier of the two (a Brix) and the overall sound level measured did not change at all, but it was clearly obvious to me, so it looks like I will have to do some testing with the dB measurement levels. The first is that it was picking up my breathing, I had it about 9" in front of my nose, whilst I was seated in my typical position, I had to breath very shallowly, this can be easily fixed by me positioning the phone where my head would be and moving away a distance for the measurement. Let us help you solve your fan and airborne noise problem.I just measured my PC from where I am sitting, so the sound level as I hear it. We at Eldridge work with fans and sound every day when we are engineering and solving industrial and marine ventilation and noise control problems. Which fan would you want? Fan A that is 81 dBA at a distance of 15 feet or Fan B that is 84 dBA at the same distance? Not much difference decibel-wise, but in reality, Fan B is will sound 2 times louder than Fan A! There is an old axiom that holds true when it comes to reducing fan noise: “Quiet is expensive.” However, you are always better off to start with a quiet fan to begin with than to try and silence a noisy fan.Īlso, it’s important to keep in mind we are dealing with logarithms here, so an increase of only 3 dB will effectively double the intensity of the noise. We can even add noise from other equipment to these values to determine the combined noise effect and then how to silence that down to an acceptable level. Once we have this measurement, we can apply silencing techniques, insulated wraps, sound enclosures, or whatever is required in order to reduce the noise of the fan. Then we would back calculate the sound power level at a specific distance used for the sound pressure level measurement:įan Sound Power Level (L w) = Fan Sound Pressure Level (L p) + Delta (Room Effect) The only practical way to arrive at a Sound Power Level (L w) is to take Sound Pressure (L p) readings at each of the eight octave band center frequencies in a laboratory setting. In general terms Sound Power Level (L w) cannot be directly measured. However, there is a problem measuring the Sound Power Level (L w) of a fan. In order to determine fan noise, Sound Power Level (L w) is what the acoustic engineer needs-something that is constant all the time no matter what the fan’s operating environment might be. Sound Pressure Level (Lp), on the other hand, changes depending on the environment in which the fan operates. Sound Power Level (L w) is like the sound fingerprint of a fan. Sound Power Level (L w) = the logarithm of the ratio of the actual power of the sound to 10(-12) watt reference. Sound Pressure Level (L p) = the logarithm of the ratio of the actual pressure to a common reference value of 0.0002 microbars There are four (4) very common terms used in acoustics:ĭecibel (dB) = one-tenth of the logarithmic unit (Bel) by which noise is measured and evaluatedĭBA = A convenient single number low frequency weighted dB scale for judging the loudness of a sound that more closely correspond to the threshold of hearing of the human ear. For example, a fan operating inside an uninsulated building is going to seem much noisier with its sound bouncing off the walls like reflections off a mirror than the same fan operating in the middle of a Texas cattle ranch. Aside from the design of the fan, speed of the fan, pressure the fan develops, volume of air going through the fan, there are external factors such as the environment in which the fan operates. I may like classic rock & roll music, but to someone else-it’s just noise.ĭetermining how noisy a fan is and what to do about it is not as straightforward as one might think. Noise is relative to the ear of the listener. So, what’s the difference between sound and noise? Simply stated, noise is unwanted sound. Fortunately, sound is governed by natural laws so we can measure, predict, and use it to our advantage just like the fan performance is governed by the Fan Laws. Capable of blasting 5,300 cubic feet of air per minute, this powerful option is well-suited for both indoor and outdoor use. Interestingly, “sound happens” whether or not anyone is around to actually hear it.
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