Ask someone looking to buy a snow blower whether they prefer a single stage or a two stage model and you’re likely to get a blank stare. Many buyers just don’t know what that means.
That’s reasonable; few sellers emphasize that aspect of the design very much. They tout auger width, power, and the more obvious features like electric versus gas-powered. Nonetheless, which of the two types you select can have a big impact on ease of use and the effectiveness of your plowing.
Single Stage vs Two Stage, Explained
Nearly all electric snow blowers and most gas-powered models feature a single stage mechanism. That means, the auger (the spinning blades, usually metal, similar to a very old-fashioned manual lawnmower) scrape the snow and push it up through the chute.
In case you’re not sure, the “chute” is the tube on top – usually moveable through 180 degrees – that ‘exhausts’ the snow and directs it away from the plow path.
That single motion can certainly be powerful enough to push up to six inches or more of dry or even moderately wet snow up to 20 feet away. If there isn’t too much ice, and the unit has a powerful motor/auger, even that can be effectively handled.
By contrast, a two-stage snow thrower (usually found on larger, gas-powered models) adds an impeller behind the auger and below the chute hole. This spinning fan takes in the snow the auger scrapes up and forcefully blows it up through the chute. The net result is the ability to draw up and expel heavier snow, farther.
Why It Matters
There are other aspects to the 1-stage and 2-stage design than simply the ability to throw mush and ice or throw any type farther. Most snow blower models that have a two-stage design are accompanied by other differences as well.
There’s the most basic difference to begin with: electric vs gasoline-powered. It would be a very rare electric model that included an impeller. They generally don’t have the power to drive an impeller in addition to the auger and aren’t designed to move heavy snow far distances.
If you’re interested in an electric snow blower – because they’re generally lighter, quieter, produce no fumes and (obviously) require no fuel – you’re almost always going to be limited to a single-stage design. Gas snow blowers, on the other hand, are typically more powerful and frequently feature larger augers and intake housings.
Two-stage snow blower designs also typically don’t have a housing/auger that scrapes the ground. So, they’re much less likely to draw in gravel or loose dirt. Single-stage models often go right to the ground. If you plow only sidewalks or even snow atop grass, that’s not a concern. If you try to clear a gravel-laden driveway or street, it might be.
Two-stage models also often feature a chain or belt drive that makes the snow thrower self-propelling. Single-stage snow blowers often (but not always) require you to supply the force to move the unit forward. Even so, the rotation of the auger will usually help pull the blower forward as it digs through the snow, even without a drive mechanism.
Most reviews will specify the type. Deciding which version to get is, of course, a matter of balancing cost, size, and personal circumstances.