Dysons again

[Andrew Gabriel]

Just found my DC07 is HEPA. Like you, I didn't want that but it was on offer at over £100 off, which made it much cheaper than the non-HEPA version. Had forgotten about that.

Well, you're describing my non-HEPA filter perfectly ;-)

Same on my DC07. However, curiosity just got the better of me, and I levered the cover off. This reveals it is the post-motor filter which is the HEPA filter on my DC07 -- it says so all over it;-) It is stained darker on the filter surface where the main airflow goes into it. This stain comes off on fingers, and I suspect it is material worn off the motor brushes -- looks like that. There are three filter components inside the HEPA filter, and the middle and outlet ones are still bright white. In my DC04 (definately non-HEPA), the post motor filter is much simpler.

[Mike Clarke]

Oops I stand corrected.

[Snip]

Thanks for pointing out my error. In the absence of any other obviously conspicuous filter I'd just jumped to the conclusion that the great big yellow thing was the HEPA filter that they boasted about in the brochures. Since the HEPA filter wasn't a major issue for us I'd not bothered to confirm this. With hindsight I don't imagine you could get HEPA quality filtering from the single layer element under the foam. I've since come across an illustration of the HEPA filter on Dyson's site and it's certainly looks much more like the business.

[Mary Fisher]

Q: what does HEPA mean?

Mary

[Andy Hall]

High Efficiency Particulate Air filter

More than you ever wanted to know at

[Mary Fisher]

Ah, thanks.

Mary

[Andrew Gabriel]

High Efficiency Particulate Air [filter].

Years ago, they were used on the non-sealed disk drives we used to use, which relied on positive air pressure through HEPA filters to keep dust out. The HEPA filters had to be changed every 6 months, and they were treated as a low level biohazard because they trapped bacteria, and hence used ones had a rather high concentration of bacteria inside them.

Like I said in an earlier post, I would not have bought that feature except it was very much cheaper by virtue of a special offer. I'm very much a believer in the modern obsession with hygine being responsible for increase in various diseases, and that the immune system needs to be exposed to a wide variety of things to keep it working properly.

The only dirt which seems to have got trapped in mine is that generated in the vacuum cleaner itself after the cyclone and washable filter, i.e. dust from the motor brushes, which considering how much it's been used and how little there was, was really quite insignificant. (Actually, the HEPA filter is designed to filter out dust far too small to see, so it might be that it is being more effective than is visible by eye.)

[graham]

I think the story goes like this...

James Dyson invented a new type of wheel barrow called the ballbarrow.

The manufacturing plant used to spray the ballbarrows with paint. They found it necessary to use a cloth filter attached to an extractor fan to remove paint and vapour in the atmosphere.

Unfortunately, the cloth filter would become blocked with paint. Every so often they would have to stop work and clean the cloth.

Dyson looked around for an alternative solution. It was suggested that they use a cyclone unit.

Dyson climbed over the fence into a wood yard and saw that a cyclone device was being used to separate out the saw dust from the clean air.

Whilst cleaning the house with his vac one day, he thought that the idea of a cyclone could be used to make a bagless cleaner.

I think he has made something like 5,000 prototypes.

I read his autobiography a few years ago. I think the problem he had was finding a way to trap certain types of large dirt (like fluff) that might normally pass through the cyclone and into the filter.

Dyson successfully sued Hoover and other manufacturers for copying his idea.

Graham

[Alan Vann]

(snippage)

A couple of people have mentiond Constellations[1] recently which reminded me: Did anyone see the news article a couple of weeks back? - The one about the guy who'd just spent 8 years inventing a vacuum cleaner that hovers on a cushion of air......

Alan

[1] An aunt had one in the sixties. Used to fascinate me when I was a kid)

[Bob Eager]

Do you have a reference?

BTW, there's a Constellation in the Science Museum...

[Andrew Gabriel]

I went to an exhibition in the V&A some years back, and they had a living room setup for each decade through the century (this was last century;-). The 1960's room had a constellation in it. I remember thinking what poor shape it was in -- mine which was still in use as the main vacuum cleaner then was in much better condition.

They come up on ebay sometimes. Hoover also produced some gimmicks after the same style -- there's a Hoover constellation expanding tape measure which is functional and looks like a minature version of the vacuum cleaner. (Never had one, but seen them a couple of times.)

Oh and yes, I learnt about hovercraft as a child pushing the thing up and down my parents' hallway. I also have a young childhood memory of sitting counting the number of consertina sections in the hose, and each time I got to the end of a decade, having to ask "what comes after 49?", "what comes after 59?", etc. (I recall the total was 115 -- I could check if I was right, except the hose got shortened a few times over the years when it wore through at the ends.) So this machine clearly played quite an educational role in my early life.

I expect today's 3 and 4 year olds all know the principles of cyclone filtration instead ;-0

[Alan Vann]

It was an article in the Daily Express, probably during the recent Inventor's show in London. The recycling wagon's been, so I don't have it anymore and the Express don't have old news on their site (that I can find) but this is the same story:

Express had a picture, but bunging airrider into Google gets this: wonder if anyone's told him yet? :o)

Alan

[Bob Eager]

Surely they must know...!

[StealthUK]

The biggest problem is people not cleaning filters regularly. That applies to any bag-free vacuum. IME they have to be cleaned far more often than stated by the manufacturers. Yes, you save on bags but you have to monitor your use and spend time next to the sink.

Still, at least you don't have to try and discretely remove the dust from a used bag with your fingers over the refuse bin when you've run out of new ones!