i measured a vaccum cleaner.
most of the electrical pollution came from its long power cord.
you could replace the cord by a shielded cable with twisted wires.
the shield is to be grounded to get rid of the electrical fields.
twisted wires produce weaker magnetic fields.
I can vouch that grounding the metal shell of an electric motor will reduce the electric field a lot. I tested it on a grounded Air King desk fan that I liked better than most others, using a "cheater" to remove the ground connection. I think the E-field was at least doubled without the ground, but I'd need to re-check to be sure. Anyway, it was a big difference. Magnetic fields were still really bad.
Another option would be a whole-house vacuum, but I've found that older Electrolux models have a lot of low-frequency noise on the wires in the hose (which power the brush attachments and turn on the central vacuum when you flip the switch).
both grounding the motor and using shielded cable will help, the first measure may be more effective.
pulling out the cable totally and keeping most of it as far as possible away will of course also reduce the electric and magnetic fields where you are.
if the cable is coiled up in the vacuum cleaner, it is too close and this coil will produce magnetic fields in addition from those from the motor and the cable.
most of the magnetic field likely comes from the motor, the rest from the cable when a current runs and from an eventual coil.
by the way, any plugged in cable, also when nothing runs, emanates an electric field.
You're right that finding a vacuum that's already grounded would be ideal. Just make sure that it doesn't have digital controls.
It's a little tricky to add grounding to a motor unless it was designed for it. My Air King fan has a screw hole in the iron part of the motor, which is where the ground wire attaches. Light ballasts sometimes have the same configuration. I can post a picture if that would help. The best way to connect that to the ground in your wall outlet is to buy a grounded replacement cable at a hardware store and hook it up to the motor's power terminals and the grounding screw.
If there isn't already a place for a ground wire, then I think the best solution would be to wrap a strip of metal screen around the motor. (Vacuum motors get *very* hot, and I think that sheet metal or aluminum foil would block airflow and cause it to overheat.) Then you would just need to add a wire from the screen to the ground in your wall outlet, but doing that in a safe way is a little bit hard.
Adding a ground connection to the iron part of the motor would be difficult because it's made of layers that are insulated from each other by a ceramic coating that wrecks drills.
Yeah, I'm not a vacuum cleaner fan either. We have one, and it doesn't bother me electrically, as far as I know, but the smell and sound bother me so much that I have to leave the room whenever it's in use (and for a while afterward). I think I'm allergic to it. I can see why dogs don't like them, with their powerful ears and noses.
Yeah, brooms are great. Even those vacuums that don't use electricity are cool.