
SEBO
AIRBELT E3 Premium
Ultra-durable, 10-year warranty, but expensive with short cord.

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Bissell PowerForce Helix. Great suction and when set to the **bare floor setting**, its suction is amazing especially for the price! https://www.ebay.com/itm/317695278433?
Ngl the best dog hair vacuum I’ve owned is a cheap a$ one from walmart. It never clogs and nothing has broken on it after a year of use. Previous ones I was breaking belts like crazy cause of my shepherd’s hair. It’s this one, $59. BISSELL PowerForce Helix, Bagless, Upright Vacuum, Pet Friendly, Scatter-Free Technology, Helix Dirt Separation System, Lightweight, 3313, Blue & Black
I agree with Flat\_Direction, I think your students would benefit the most from using the most common vacuums they will come in contact with. The cheap Eureka and Bissell stick vacuums are not what people commonly buy to clean carpets. The Eureka Airspeed is most like the average bagless vacuum. The most common vacuums are Bissell PowerForce Bagless and Shark Navigator vacuums. Sadly most box stores don't sell bagged vacuums and canister vacuums are rare so I wouldn't get them for your students. Bissell PowerForce Helix #3313 $59 (walmart) Shark Navigator NV380 $118 (walmart) With the Bissell PowerForce, Shark Navigator, and Eureka Airspeed your students can practice emptying the bin, checking the filters, and using a hose and tools. The little stick vacuums don't have a hose and tools and their bins/filters are not the common bagless upright design. Hope that helps.
We buy Bissell PowerForce Helix for 70 to 90 bucks and treat them as disposable as an expense. We mostly do commercial work and usually get at least a year out of them before the beater brush wears out. Been doing this for 35 years, we used to buy expensive heavy duty commercial vacuums but maintaining those got to be an issue. We just came off a trade show vacuuming 12,000 square feet every day for a week, the Bissells were dependable and never failed. Just my opinion of course.
We used to buy expensive commercial vacuum cleaners but we switched over to inexpensive residential vacuums years ago and treat them as a disposable expense. The last 10+ years we've been using Bissell Power Force Helix bagless. It's a Walmart exclusive that's available for 67 - 90 bucks. We buy one for each job and leave it on site. They usually last a couple years with heavy use. The filters are easy to clean or you can buy replacement filters cheap and just replace them occasionally. By the time the beater bar or belt wear out it's time for a new one.
I got a bissell powerforce Helix from Walmart and it’s amazing. I used to stick with shark but this bissell sucks up everything and makes the carpet look like new (and I have a husky!) I even bought the handheld bissell to go with it They’re like 120 at Walmart
Definitely don't go cordless for work. I really liked the clients vacuums that I used that were shark brand and had lights on the bottom. They worked good and felt very nice to use. The long skinny ones would be good if you have a lot of clients that want under furniture done or tight spaces. I have a basic shark pet vacuum that i bought years ago in my home and i love it. Still works great. I had a Bissell powerforce helix provided by work and honestly that worked pretty good. No fancy features, but it was light enough to carry with a good handle and did most jobs well with regular maintenance on the vacuum (you definitely need to clean the filter weekly if you clean daily) edited to add that last sentence

SEBO
AIRBELT E3 Premium
Ultra-durable, 10-year warranty, but expensive with short cord.

Numatic International
Henry Canister Series
Budget king, super durable, but heavy and poor on carpets.

SEBO
AIRBELT D4 Premium
Durable, powerful, long cord, but heavy and pricey.

SEBO
FELIX Premium
Durable, powerful, good for allergies, but heavy with awkward attachments.

Miele
Classic C1 Cat & Dog PowerLine
Durable, powerful, quiet, but very expensive, short cord.

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
SEBO - AIRBELT E3 Premium

Ranked #1
Numatic International - Henry Canister Series

Ranked #1
Dyson - V15 Detect Series