Whisper Aero wants to revolutionize electric aviation with propulsion systems 100x quieter and 20% more efficient than anything else on the market. While it's working on that, it's thrown together a quiet, powerful, efficient leaf blower as a demo.
It's not a bad place to start; both aircraft propulsion systems and leaf blowers need to shift bulk air, and both are too frickin' loud to be used near my bedroom window before 10 am.
Whisper's technology, as we explained when the company came out of stealth, centers around its "propulsion disc." This metal fan uses a small diameter to keep blade tip speed down, a large number of blades to generate high thrust at lower RPMs, and a shrouding ring around the outside to keep the whole thing strong and stiff.
The densely packed blades also move the "blade passage frequency" well over 16,000 Hz, pushing a lot of the associated noise up out of the range of human hearing – but not high enough to annoy dogs. The noise-deadening effect looked pretty convincing when demonstrated at propeller scale.
But what about at lawn care scale? The Whisper team threw a prototype leaf blower together to find out. And while it looks disturbingly like those pee bottles they give you in hospital, it delivered strong results – at least, as reported by Whisper Aero. Check a video out here.
Back-to-back against competitive electric blowers from Makita, Ryobi and Stihl, it recorded 45 dBA at 50 feet, some 12 dB under the quietest of the competition and perceptually less than half the noise.
But it also pushed 875 cubic feet per minute (CFM), well up on the Ryobi's 672 CFM in second place, and used 1,080 W of power where the Ryobi used 1,148 W, moving more air with less power. The Makita blower, for reference, used 1,500 W and pushed only 634 CFM, presumably losing a lot of its power making 61 dBA of noise.
Whisper isn't going into the business of leaf blowing; as with the propulsion systems it wants to license its tech to manufacturers. Indeed, according to TechCrunch, it's already "in talks with a few potential partners" to make that happen, with hopes to have a product rolling out by 2025.
If the riveting video linked to above wasn't enough leaf blowing for you today, the company has also produced a handy POV version that really puts you in the blower's seat. Check it out here.
Source: Whisper Aero