Bypass motor with most airflow

[wyaple]

Replies

Mikko,

What a drop in airflow from your "bag saver"! From a 6 to a zero. That would mean:
93 CFM (a "6") - 46 CFM (a zero) = 47 CFM loss due to the cyclones.

Mark,

It's pure physics. Cyclonic machines will always sap airflow because they make the air "do extra work".

Examples:
Dyson DC14 cyclone loss is 43 CFM
Dyson DC25 cyclone loss is 45 CFM
Hoover Windtunnel 2 Pet cyclone loss is 58 CFM
Hoover Windtunnel MAX cyclone loss is 48 CFM

Bill

 

[mike811]

Airflow = cleaning performance

It was clear to me that the bag saver steals suction, but shocking was how much. There is many nice bagless vacuums what I like (like the Shark Rotator), but this just make me think. I have tested all my vacuums with deap cleaning (shag rug) and airflow is straight related to the pick up performance. Higher airflow vacuums just deep clean better.

 

[sebo4me]

The Baird meter has shown that bagless cleaners have low airflow due to the action of the cyclones yet the Shark gets a Silver award from the CRI which is a high level and the Shark Powered lift away gets a B rating for carpet pick up in the EU, the ratings go from A to G so that is a high rating too.

I'm a little confused. How can a cleaner with such low airflow still get a high ratings?

 

[sebo4me]

I agree Sebo could update their "Domestic range" and add more features but whether they will is a different matter!

I do like the E3 Premium. If I were to choose between that and the Miele PN model i'd choose the Sebo.

I understand Go Vacuum stopped selling Miele in favour of Sebo. There is a reason why

 

[mike811]

Testing it

So I made a video showing how much the cyclonic system in the bagless Electrolux UltraFlex steals the airflow.
First I measured it with the air going through the cyclone.
Then I measured the airflow bypassing the cyclone.
Cyclone in use result was 5 and without it 8. So 85 cfm trought the cyclone and 104 cfm without the cyclone. Drop was 19 cfm. Not too bad in this vacuum cleaner.
I also tested the turbo brush spin speed. This needs airflow and suction. There was also drop in the spin speed with the air going through the cyclone.
Next is going to be deep cleaning performance test with lof cfm vacuum vs high cfm vacuum.

 

[sebo4me]

So it is possible to manufacture a bagless cleaner that still has decent airflow. Still a loss in CFM but respectable.

 

[crazykirbydude]

Or...

The Electolux Model 30!!! It pulls more than my Dyson, and you can run it until the bag is PACKED! The best part is, they are pretty much indestructible. You can get one on EBay for something in the range of $40. I really love mine!

 

[wyaple]

Mikko,

What is the power usage of your Electrolux UltraFlex? 85 CFM through the cyclones is probably a record! My Dyson DC14 can only do 77 CFM (measured through the hose), but that's using 1296 Watts (brush roll spinning on carpet).

Bill

 

[mike811]

Bill

Well now it uses 2100w motor. Original motor was only 700w (EU regulation model). It felt too underpowered. So when I got a bad vacuum for free with good motor, I swapped it. Performance increase was huge, but so was the noise level. I should have bought the original Electrolux motor It would have been much quieter and better quality + it would had same dimensions than the old 700w motor. Those +2000w vacuums were common before EU regulations.
However the end result was nice what it comes to performance.

 

[wyaple]

Well no wonder you have reasonable cyclone airflow then...



Let's do an efficiency calculation, shall we?

2100 Watts / 85 CFM = 24.7 Watts per CFM for your UltraFlex
1296 Watts / 77 CFM = 16.8 Watts per CFM for my DC14

I can only imagine how poor the airflow was using only a 700 Watt motor. I'd guess something like 30-40 CFM, which would be very difficult to vacuum with. I'm still amazed that such a large motor fit. Did you have to make many modifications to get it to fit?

Bill

 

[mike811]

Bill

2100 motor is bigger in diameter and it didn't fit straight on. I had to cut some parts inside the motor compartment.
There was also problem with the motor mounts. It was very hard to get it sit right and I had to made new front gasket for it.

2100w motor what I use in it now is from the cheap vacuum. It's so called screamer motor. A bit annoying to my ears.
UltraFlex is designed to be used with the 700w motor. So all airways are designed to be efficient as possible to compensate the small motor.
US model UltraFlex has a 12amp = 1300w motor. Suction in it is 250 airwatts. 700w = they don't tell.

Mike