Water vacuums

When it comes to suction, conventional vacuum cleaners tend to... suck, for want of a better word. Bulging bags and clogged filters progressively reduce the airflow and the suction, making it impossible for them to pick up more dirt effectively. Without filters, however, they blow quite a lot of the finer dust (the harmful particles known as PM10s, smaller than 10 microns) back into your room; so, instead of "vacuum cleaning", they are simply "dust rearranging": sucking in dirt and blowing it back out so it settles somewhere else. That's a particular problem for people with asthma or dust allergies.

What's the solution? One option is to use a water vacuum, which uses a tank of water to trap the dirt instead of a bag or conventional dirt bin. The dusty incoming air fires into the water tank, where the dirt is held in solution. The moist air that leaves the tank is then spun around to remove the water (a bit like in a Dyson), producing clean air that flows back into the room.

Here's how a typical water vacuum works:

Air is sucked in through the brush bar in the usual way.

A powerful motor (not shown) pulls the air through a water tank, where most of the dirt is trapped.

The moist air continues through the tank, spiraling past plastic plates, which help to separate out the water droplets from the air that carries them. The water drips back down into the tank.

Clean, dry air exits through an outlet on top of the machine.