Vacuum Cleaners Discussions

Technically, the Rainbow vacuum was the first to not lose suction.  It uses a more primitive dual cyclone design with water as a pre-filter.   If the Rainbow didn't have such a ridiculously high price and clumsy power nozzle, it would be a pretty good vacuum.  I don't know why they require you to hold a button down to keep the power nozzle operating.  One would think that they would use a simple 2-way switch.  All that on/off cycling can't possibly be good for the power nozzle motor.   The Rainbow uses an innovative brushless motor.  It would be a pretty good $800 vacuum with a better power nozzle. 

Just, Rainbows don't have "digital motors" by which I think you really mean brushless reluctance motors. Rainbow uses and has always used very conventional commutated universal motors. The current motor is a small single stage motor, not the big two stage motors of old. They have very weak airflow and suction compared to modern canister vacuums. My E2 barely pulls my BAIRD meter off the bottom of the scale at 0. An old Electrolux Silverado pulls the BAIRD meter up to 7 and my modern Kenmore Elite pulls the BAIRD meter off the scale past 10. Also, 90 cfm airflow is only so-so. Most modern canister vacuums produce more. A simple Pro-Team back pack vacuum pulls 110 cfm. An old Hoover Dimension 1000 pulls more than that. As for filtration, water vacs still need HEPA filters because all of the dust entering the water chamber is not entrained in the water. Very light particles get past the motor and require HEPA filtration to capture. A modern bagged canister vacuum using a good cloth HEPA dust bag and filters does every bit as well.