Inside Airvolution...

[vintagehoover]

A couple of months ago, I posted photos of the inside of Vax's 'No Loss of Suction' system. Here's Hoover's own take on Dyson's multi-cyclonic separator, known as 'Airvolution'.



The complete Airvolution cyclone chamber, removed from the cleaner



With the top flipped up to reveal the pre-motor filters



Pre-motor filters







The inner workings consist of a shroud, 2 Riser Ducts, and 12 V-Cell Separators





Exploded view of all componants

 

[watsonw]

Jack,

In your opinion how does the performance compair with the Dyson system ?

Regards, Walter.

 

[vintagehoover]

Hi, Walter -

I've extensively used the Dyson system, the Hoover system, and the Vax system, so I feel relatively well-qualified to answer your question!

In my opinion, Dyson's system is the most efficient, and with good reason; it's been improved continuously over 30 years, and Sir James and his army of design-engineers have already developed and patented all the best technology. Dyson Root Cyclone technology is protected by no less than 820 patents.

However, both Hoover and Vax have made very reasonable attempts at developing systems which do approach the efficiency of Dyson's.

I think that after Dyson, Vax's 'No Loss of Suction' system seems to be the next-best contender. At least, after continuous use in a number of houses since I acquired it in February, the pre-motor filter of my Mach 7 remains relatively dust-free. Wondering if the fine dust had simply passed right through the filter, I took the cleaner apart, and wiped around the inside of the motor-casing with a black cloth. There was no trace of fine dust inside the compartment, or in the air-ducts. And the post-motor filter was only discoloured by a slight trace of carbon emissions.

Hoover claim 95%+ separation-efficiency for their 'Airvolution' design. In practical terms, this means that 5% or less of the total volume of dust picked up should go through to the pre-motor filter.

However, after a single use, the Hoover's pre-motor filter is noticeably more discoloured with very fine dust than either the Dysons or the Vaxs'. To demonstrate, here are a few more photos. When I took the photos I've posted above yesterday, I cleaned all the parts as I went along, then washed both the filters. Today, I've used the Slalom to vacuum my grandparents' house. It got about an hour's use, and covered 8 rooms. The dust reached, but did not exceed, the max line.

Despite the dust build-up, however, I must stress that there was no appreciable drop in cleaning performance.



Dust in the chamber...



Tipped out on an A4 sheet of paper...



Unsightly dust...clinging fluff...damaging grit...



Fine dust, a few grains of grit, and a strand of hair, which have passed through the system...



And finally, the fine dust on the foam filter, which sits underneath the HEPA filter.

 

[bagintheback]

vintagehoover, why do you think there is that much dirt on the filter? At least it trapped it!

How many cyclones do the Vax and Hoover have? I believe the dyson has 8?

Like my user name, I like a bag in the back!

Nathaniel

 

[vintagehoover]

There's actually only a light layer of dust on the surface of the first filter. Compare the total amount of dust that the cleaner picked up with the amount which made it to the filter - not a lot, is it? In reality, the fine dust has little to no effect on performance until around 3 months-worth builds up. Then you wash it and you're ready to go again. And as you say, it's trapped in the filter. Very little gets through the HEPA filter, and even less through the post-motor filter.

The Vax has an outer cyclone, followed by 7 high-efficiency cyclones. The Hoover has an outer cyclone, followed by 12 high-efficiency cyclones.

As for the Dyson, it depends which model you're talking about. There are several variations of the Root Cyclone design.

Bagged and bagless cleaners have their strengths and weaknesses. I don't feel the need to pick one or the other. They're not political parties!

 

[joe22]

God bless the guys in marketing for comming up with the word, 'Airvolution' joe

 

[kirbyduh]

which

dyson cyclone system is the most effective?

 

[rolls_rapide]

I would imagine that the 'Root Cyclone + Core Separation' version (also known as 'Level 3 Root Cyclone') is the most efficient.

The intermediate stage allows larger particles, such as grit which can get past the shroud, to be separated out before going near the multitude of small, high efficiency cyclones.

As for Jack's view on the Vax versus Hoover efficiency, the Vax models have airflow baffles in the vortex finders of the small cyclones (as do Dyson). The Hoover 'Airvolution' does not appear to have any baffles. (Baffles stop the central airflow in the conical cyclones from spinning, thus increasing airflow efficiency).

 

[vintagehoover]

Rolls_rapide - I agree about the Level 3 Root Cyclone being the most efficient. And thanks for making the point about the cyclone baffles - you're correct, the Hoover system doesn't have these, which is possibly why more fine dust gets through.

I'd rank the separation efficiency in the order:

1st - Dyson
2nd - Vax
3rd - Hoover

But again, I'll stress that in normal use, the claim 'no loss of suction' rings true for all of them. If there is a decline in suction or airflow, it's negligable, and not enough to affect performance.

I definitely think for anyone selecting a bagless cleaner, it's essential to choose one with multi-cyclonic technology. For me, it's what makes the bagless system a viable option. I wouldn't recommend a filter-based bagless system to anyone. The compromise on performance during use, and the maintenance required to keep performance optimum, is too high.

 

[turbo500]

Jack, that is exactley what I detest about bagless cleaners. Given the exceptions metioned, most bagless cleaners just use the filter based bagless system and after vacuuming just half a room, you've already lost suction. Also I find emptying any bagless cleaner and cleaning the filters to be a very messy and unhygenic job. I know you are a fan of some bagless cleaners. I think they are very interesting machines with good performance (apart from the stupidly soft brushes on the Vax) - especially to see what comes out of the carpet on a daily basis. But I cannot abide having to empty them and clean filters. All the dust just seems to poof back up in my face - even when empyting outside into the wheelie bin. I'd sooner just drop a bag in the bin and save the mess. I was helping a friend out recently who'd been in a car accident and couldn't vacuum as she injured her back. I used her DC07 and when I emptied it, I got COVERED in very fine dust and ended up breathing a lot of it in and taking most of it back into the house with me. I just find this a very annoying process.

 

[watsonw]

Jack,

Many thanks for taking the time to give such a comprehensive
account, I knew you'd know.

Regards, Walter.

 

[rolls_rapide]

"All the dust just seems to poof back up in my face...&

I know what you mean - I generally end up sneezing. It tends to do that even more if you have just finished cleaning and then go to empty the cyclonic bin, as the plastic of the cyclonic bin will have frictionally applied an electrostatic charge to the dust. Best to leave the bin for a day, then empty it before the next cleaning session, as the static charge will have dissipated by then.

Trying to empty into a plastic bag (a la the Dyson 'Allergy' method) is just as awkward, as you have to juggle the bin, the bag and the trapdoor as you try to keep a tight grasp of the plastic bag. When you consider that this method puts a plastic bag into the environment, it really does make a conventional paper Hoover bag much more environmentally friendly after all.

 

[vintagehoover]

I think I live in some alternate universe, where I treat vacuum cleaners well, and they treat me well in return! I don't find emptying Dysons messy - they're probably the cleanest of all bagless cleaners to empty. Hold the canister over an outside bin, pull the trigger, and the dust falls out from the base. I've never noticed any significant quantity of airborne dust - although to be fair, I don't have any dust-related allergies. Click the base shut again, and if any fine dust has stuck to the outside, wipe off with a cloth. Put simply, if I encountered the same issues with bagless cleaners as some other people do, I wouldn't use them as often as I do!

I find it odd that people protest about particles of dust on the outside of a cyclone canister - wipe it off!! We use dusters to wipe dust from shelves, table-tops etc, without making a fuss about it. Dust is everywhere, on everything, and we're breathing it in all the time - along with other general atmospheric pollution!

And I can't say I agree with the enviromental benefits of bags, either. If they're bleached paper, they're made by chopping down trees and adding chemicals. And if they're Miele 9-layer fleece bags, they're going to take centuries to biodegrade! At least plastic shopping bags are there already. And unless you take the time to recycle them, they're going to end up in a landfill anyway. Might as well put them to some use!

 

[turbo500]

Jack, maybe you've just been lucky. Certainly every Dyson I've ever emptied has blown a significant amount of dust back at me. I've even tried leaning right into the bin and doing it but I still get fine dust all over me. I had a bit of an annoying thing happen once when emptying my gran's DC04. The bin was almost full and I tip out all the dust into the bin and because it was windy, ALL the dust blew straight back onto me - but that was my own stupid fault lol. The one thing I agree with on the Oreck infomercial's is that bagless is unhygenic as all the dust particles - including dead skin flakes and dust mite droppings - just ends up all over you. As for the dust on the cylinder - well that doesn't bother me so much. I get dust on my Sebo, Miele and Henry. I think most of it is dust in the air that clings to the outside of the cleaner due to the static caused by the machine and not dust blowing out of the vacuum and it is easilly cleaned. It is just a bit annoying having to put a clean t-shirt through the wash and having a sneezing fit JUST because I emptied my vacuum.

 

[rolls_rapide]

But they're not - that went out when they stopped making the bright yellow bags. Today's bags are usually unbleached brownish paper.

 

[rolls_rapide]

That was weird! I put a subject drift header, posted, then I was asked to log in. It posted, but removed the header!

 

[vintagehoover]

Ok - well, they're still paper, bleached or unbleached! And once they're all full of dust, it's not like you can recycle them.

 

[riccarlover]

Jack does make a very good point...

Going bagless is a green way to go!!!
That is one thing that is nice about having a bagless machine. No bags to throw out and its like starting out with a fresh bag every time you dump it (which most people dump it after every use).
Clayton

 

[kirbyotronic]

"It tends to do that even more if you have just finished cleaning and then go to empty the cyclonic bin, as the plastic of the cyclonic bin will have frictionally applied an electrostatic charge to the dust."

Just a small idea, would it help to throw an anti-static dryer sheet into the bin and run the cleaner?

~Alex