Less noise, no fumes – testing cordless leaf blowers

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ReNew reader Colin Dedman puts the latest generation of lithium-ion cordless leaf blowers to the test and is blown away by how far they’ve come, though price and run time can be an issue.

Why would you buy a cordless leaf blower? Why would you buy a leaf blower at all? For the most sustainable living, shouldn’t we rake up all our leaves and debris by hand, and clean out our gutters by crawling around on the roof?

For those of us with rainwater tanks, cleaning the gutters frequently is a necessity rather than a luxury, to ensure that precious rainwater ends up in the tanks rather than spilling out of a blocked gutter. For many years I cleaned up the leaves by hand, while cursing the weekly scream of my neighbour’s two-stroke leaf blower. Then my aging back convinced me that if you can’t beat them, join them, so I purchased my own screaming $88 petrol blower, that does clean the gutters and patio well. But I hate using it on account of the noise, fumes, hard starting and mixing/storing of two-stroke fuel. There must be a better way.

Corded electric leaf blowers are quieter, always start first time and can potentially use renewable electricity, but the inconvenience of a long extension cord rules them out for me. What about the electric cordless blowers then—are they just ‘toys’ as many people think?

Here I blow away the myths, by subjecting a variety of cordless blowers to a series of standard tests so you can judge which blower, if any, is suitable for your needs. I’ve included two mid-range petrol blowers and a corded blower in the tests for comparison.

Measuring blower performance
Some manufacturers would have us believe that the all-important parameter is the air flow rate in cubic metres per hour, while others boast of their impressive discharge velocity in kilometres per hour or metres per second. In reality, both are important.

The most useful single parameter to measure a blower’s effectiveness is the blowing power in watts (W), being the power of the moving airstream, as this relates directly to the ability to shift stubborn debris and move a lot of leaves and debris in a short time. The blowing power is less than the input power, due to inefficiencies in the motor and fan.

Manufacturer published values of air flow and velocity have not been included, because they are sometimes incomplete or inconsistent. In one case the specifications printed on the box were different to in the user manual—both can’t be right! Other issues include quoting the peak rather than average velocity at the discharge nozzle, and quoting the higher flow rate without the nozzle attached. Therefore, to enable meaningful comparison of competing blowers, I’ve measured the air flow rate, velocity and blowing power according to ANSI Standard B175.2, using calibrated equipment, and tabulated this for all the blowers tested, providing a resource for comparison of blower performance.

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