Take a look at these two vacuums below. See a major difference? Indeed, the purple one has a much larger head. But why is that? Does it mean that the suction coverage area is bigger? Well… no, not necessarily.
The purple one is bigger because on the head of the machine is an extra motor. This extra motor’s job is to spin the roller on the machine. This allows the primary motor on the machine to focus on just generating suction, resulting in a more powerful machine. For those of you who have read my post on rollers, you’ll know why they’re important. If not, click here!
Most of these duel motor machines have a switch to turn on one motor or both, because you might not want your brush roller furiously clawing at your bare wood or scratch sensitive floors.
However, having two motors is the leading cause of price raises in vacuums. This is the main reason why an upright usually costs less than a canister vacuum.
There are also a few uprights that have dual motor, but all of these are commercial machine, and there are only very few of them out there. The Oreck on the left has a single motor, while the Procare on the right has a duel motor. They say that a dual motor machine compared to a machine with a single motor has double the suction, which makes sense when you think about it.