At full throttle, we have measured the noise level of our fans to be near 94 dB, (measured from four feet behind the fan at full throttle). In addition to the lower dB measured, we have received many anecdotal reports that VENTRY Fans simply produce a less severe sound than other blowers. There are scientific reasons for this having to do with our propeller blades and open flow guards.
It is a fallacy that more propeller blades mean more air. Multiple blades stir the air rather than push it, wasting energy in the form of noise. This is called “form drag” or “eddy making drag” and is due to multiple tips and greater surface area. The propellers on all fans, even VENTRY Fans, make the vast majority of the noise, not the engines! See also the Propeller page and the Guard page for more on noise.
Click here for a 1-min video proving how solid shrouds would decrease fan performance.
Note that different brands of PPV Fans vary significantly in how loud they are even though they use the same Honda engines.
Beware: The noise a fan produces is NOT an indication that it is blowing more air, more forceful, or working better. Noise is often a sympton of wasted energy. The bigger the engine and less efficient the prop, the more energy is wasted and the louder a fan will be. This is related to the other common mistake made when shopping for fans: assuming the higher horsepower fan moves more air.
Fire fighters sit and chat next to a running VENTRY Fan . Click image for larger photo. Click here to go to the gallery.
Ventry Solutions disagrees with the following arguments which have been about fan noise...
TRUE STORY: We once had a fire department call us and complain that their VENTRY Fan was not working very well. Why did they think that? The VENTRY Fan was not making “enough noise!” They just assumed that to be effective, fans also had to be painfully loud. Not true! Not with VENTRY Fan!
Have you ever heard of a firefighter (or anyone else) asking for a tool to make more noise? Due to reverberation within the structure, it can be very difficult to ascertain a noise’s direction and can increase the interior crew’s disorientation! We recommend turning on the VENTRY Fan Safety Light instead relying on noise. A light at the end of the tunnel guiding you out of the structure is much more comforting than a painful racket.
Secondly, fan noise can definitely interfere with communications and should be minimized wherever possible. Crews are often near the fan and must be able to hear.
Reduced noise levels are just one of many benefits of VENTRY Safety Propellers. For more about our props, click here.