Calculating Decibel Levels with Increasing Fans

[shemer77]

I was wondering how I would go about calculating decible levels with increasing fans. Here I'll explain
1 fan is 45 decibles but we know that 2 fans is not 90 decibles, so I was wondering how i would go about calculating how many decibles 8 fans is.

 

[mathman]

Decibels are on a log scale. Ten decibels (one bel) means the energy of the sound is ten times as much. For 2 fans add 10log2 ~ 3. For 8 add 10log8. The log in this equation is to base 10.