Bill - I don't have the exact CFM & waterlift numbers for the Miele C3 canisters right on hand, I will have to do some digging around & see what I can find. But, then again, might I remind you that you yourself claim to know this....after all, it was YOU in your reply posts 25 & 26 that claims to have the actual numbers.
As for your testing & the Baird meter, again I do appreciate your tests & find them interesting. I was not aware you use a digital anemometer in addition to the Baird meter as part of your tests. However, I still do not believe the Baird meter, regardless of how it is used to test a vacuum or which vacuum is being tested, & do not believe it can be relied on as a accurate measuring tool to measure vacuum airflow, & as I said above, it is designed to produce false airflow number designed to make a Kirby look good during a in-home demonstration. It's bad enough, I personally think it should be banned!
Regarding the correlation between high waterlift & high airflow CFM numbers for vacuum motors, & how you need high waterlift to produce high airflow CFM, I was referring directly to clean air vacuum motors, the type used in canisters & clean air uprights. I was NOT referring to direct air motors, as there is hardly any produced anymore, & those that are don't publish those numbers.
Furthermore, the Hoover Tempo & Hoover Convertible you point out as your examples are actually BAD examples, & go to prove even more what I am talking about here. What your testing DOES NOT account for, & this is crucial, is how well the cleaner maintains it's airflow as the bag fills. Regarding direct-air uprights, the ONLY ones that don't drastically lose airflow as the bag fills are ones that have a bell-shaped powerhead, such as Kirby, Royal, & the designs used by GE & others in the 30's & 40's. The other designs....side mounted motor with fan on one side/belt on the other, such as Oreck, Hoover Elite, Eureka Bravo, etc....& bottom mounted fan & belt, such as Eureka F&G & Hoover Convertible, all of them lose their power VERY QUICKLY, with the bag being only 1/4 or 1/3 full before they lose 60 to 70% of the airflow they have. Most bagged clean-air uprights, with some exceptions are just as bad, due to gravity. With the vast majority of them, dirt enters the top of the bag, falls to the bottom, & starts building up on top of the motor vent & pre-motor filter inside the bag, which in turn suffocates the motor & chokes off the airflow, again most having only 60 to 70% airflow left with a bag being only 1/4 or 1/3 full. Canister vacuums, on the other hand, do NOT have this issue, since the bag is on it's side inside the vac, which means they maintain their airflow better than clean-air uprights. Provided the canister in question has a properly designed bag chamber, & HEPA Cloth bags are used, it will outclean a clean-air upright & match the performance of a Kirby or Royal. The only exceptions are bagless uprights, & some newer designs that avoid the bag coming into contact with the pre-motor filter, such as the Kenmore PowerFlow/Panasonic OptiFlow system. Ever wonder WHY Hoover made such a large bag for the Dial-A-Matic, yet they made the actual usable capacity of the bag so small? They knew what impact a filling bag would have on airflow & the vacuum's power to clean properly!
So, Bill, your statement above that a canister vacuum's airflow will be worse than a upright is FALSE! And if you REALLY think your statement is true, then I challenge you to go ahead & take 10 identical uprights, put them in people's homes, have them use them normally as they would to clean otherwise, & then check back in a couple of weeks & test their airflow with partially filled bags. I guarantee if you tested those cleaners with partially filled bags, you wouldn't be so impressed with their performance!
Even your own testing even proves you wrong! In your test results, you show that a 1980 Electrolux Olympia One has a PN CFM density of 3.55, beating out a Kirby Heritage II with 3.33 & a Kirby G6 with 3.54, & coming pretty close to matching a Kirby G5 with 3.69 & Kirby G4 with 3.61. Considering this is isn't even a modern canister vacuum, & has only 85" waterlift, I can only imagine how much better PN CFM a modern Miele, Sebo or Riccar/Simplicity canister would have.
And by the way, my opinion comes from REAL LIFE EXPERIENCE. My Mom, when she was alive, had her own cleaning business for over 37 years, & we both cleaned many commercial & residential properties together, & we used pretty much everything available for residential & commercial use. You name it, I have seen & used it!
I'm not just someone with a hobby who decided to "test" things at home, I have REAL experience using both uprights & canisters, & I know what the heck I am talking about! So, let's see your testing reflect results with REAL LIFE test results, & then we'll talk! Maybe next time you'll think before you challenge someone who REALLY knows what they're talking about.
Rob