A room for dropping things on carpets, a big smashing machine and very clean bathrooms... Rhodri Marsden takes a tour of Dyson's nerve centre

My friend Tim threw a Christmas party last year. He throws one every year, but last year's was particularly memorable; not just for the festive carousing in the living room and kitchen, but more because he'd installed a Dyson Airblade in his bathroom. As household status symbols go, this vastly eclipses a Smeg fridge or a walk-in wardrobe and Tim knew it. While airily avoiding any questions about how much the thing had cost him, he encouraged guests to "have a go", as if it were some kind of fairground attraction. Which it kind of was. More hands were dried more efficiently and at a lower cost to the environment during that shindig than at any previous party Tim had thrown, which isn't something I've heard him boasting about, but maybe he ought to.

During a tour of Dyson's research and development facility in Malmesbury, Wiltshire, I'm politely asked by Sam Bernard, their head of Commercial Product Development, if I've ever used an Airblade. Fortunately, there's no need for me to recount my Christmas party story, because I'd used one five minutes previously. Dyson HQ's toilets all carry large signs asking you to try it ("Your hands will be dried hygienically in 10 seconds") and after I've watched Bernard's presentation detailing the bacterial nightmare of old-fashioned hand dryers, I feel the urge to visit the Airblade for a second time.

"Traditional hand dryers don't dry your hands," he points out, almost unnecessarily; it's something we've all been painfully aware of for decades.

"Not only that," he continues, "they heat up dirty air from the room and then blast it back out again. The Airblade filters the air first, wipes the water from your hands with 'air knives' – the width of an eyelash – and traps the water within the unit." The case for the Airblade is closed later in the facility's microbiology lab, where scientists Karen Hall and Josephine Hoenderkamp subject me to a faintly humiliating test which reveals the disgusting amount of bacteria present on my hands and how much of that remains on wet hands after washing.

"Hand drying is as important as hand washing," says Bernard.

He's employed by a company that produces a hand-dryer, but you can't argue with the science. I wash my hands again. And dry them. Again.

It's unusual for such a facility to have its own microbiology lab that tests for bacteria and breeds dust mites, but many things about this place are out of the ordinary. For starters, it's festooned with vacuum cleaners, Dyson's best-known product; they hang decoratively from the walls, sit unobtrusively in corners and are even displayed in plastic boxes set into the walkways. Secondly, it's massive. Dyson came in for much criticism nine years ago when, in a cost-cutting exercise, it transferred its manufacturing facility from Wiltshire to Malaysia with the loss of 800 jobs. But the subsequent success of the company has prompted a massive expansion in research and development. £42m was spent on R&D in 2009 and in 2010 Sir James Dyson ordered that figure to be doubled, thus doubling the number of engineers recruited in the UK. "I seem to spend most of my time interviewing people," laughs Bernard. As we move slowly around the building, there are clearly large areas where prying eyes aren't welcome and thumbprint recognition technology is deployed to keep nosey parkers firmly out. In addition, each room is quickly checked before I'm allowed in, just in case someone has left a top-secret prototype lying around.

"Lots of our initial work is still done with cardboard and glue," says Bernard. "People do tend to run about testing them. Oh and the fire alarms go off fairly regularly, too."

The idea of stubbornly confronting persistent failure is one that seems to be drilled into Dyson employees. A quote by Edison appears on one wall: "I've not failed," it reads, "I've just found 10,000 ways it won't work." And while the story of Sir James's rise from arts graduate to billionaire inventor and government adviser is ultimately one of success, it's strewn with innumerable stories of him getting things wrong.

His first invention, a boat called the Seatruck that could deliver heavy payloads in rough seas, involved endless, tedious hours dragging planks of plywood behind a Land Rover on the beach. The dual-cyclone vacuum cleaner that eventually made his name was inspired by the design of a timber mill, but needed 5,127 prototypes before it was deemed ready – and even then no-one would buy the patent. "The industry model at the time was predicated upon selling replacement Hoover bags," says Bernard, wincing slightly. "Sorry – that's the only time you'll hear the H-word in this building, I promise."

The Japanese, however, were more receptive and success in the far East saw Dyson launch his own company back in the UK.

One room here is still dedicated to furthering the science of picking up debris from carpets. A machine designed to evenly spread and grind dirt into the floor is operated by Senior Test Technician John Merchant, while behind him hangs an array of floor coverings that would be the envy of any carpet showroom. "Different parts of the world have different floors – hard wooden ones in Japan, nylon carpets in the USA," says Merchant, "so we produce different machines for different markets." On the shelves sit jars of lentils, rice and miscellaneous objects that might be encountered by the average vacuum cleaner, although no jar of Welsh border collie hair which, according to John, the photographer, is "a nightmare". While he seeks advice from Merchant, I nip out to the mechanical test area, the centrepiece of which is a £25,000 machine that smashes products into the ground at high velocity in order to establish their strength. "This would obviously be a very tedious job for someone," says design engineer Leigh Ryan, "and one that would be prone to error through people getting tired and bored. So this is the best way of testing for wear and tear."

The sound of plastic slamming into hard surfaces becomes a familiar one throughout the day. "It's therapeutic," says Bernard. "We like to get interviewees to hit products; to jump up and down on them. It's all part of trying to make things better."

The word "better" is something of a refrain at Dyson. People like stuff that's better, we're told, and that's the ethos behind the huge sums invested in research and development.

Dyson engineers, says the blurb, are more interested in how things work than how they look. "To be honest," says Bernard, "we've launched some ugly products. But we've never launched anything that doesn't work."

Indeed, a planned Dyson vacuuming robot went as far as a press launch before manufacture was halted because it wasn't up to scratch. Work apparently continues on it. Bernard believes that this quest for perfection over schedules has been crucial to the success of the company. "Our rivals are very slow to innovate. The vast majority patch up the same components in new packaging and present that as a new product," he says. "The only other company I can think of that has a similar model to us is Apple and look at the success that both of us have achieved."

When you get 550 mechanical engineers, industrial designers, microbiologists and product designers together under one roof, ideas come thick and fast. "We're openly encouraged to pitch ideas," says Leigh Ryan, "but it has to be kept on track. You know – focused. You won't get anyone coming into a meeting saying: 'Oh, let's make a flying car'." In fact, a recent focus of Dyson's research has been on something that most consumers would deem incredibly mundane: the motor. Digital, brushless motors were crucial to the development of the Airblade and also the Air Multiplier, the company's bladeless fan. "Five years of development went into the Airblade motor," says project manager Matthew Childe. "It runs at 100,000rpm – five times the speed of a Formula 1 car motor – and it doesn't wear out in the way traditional motors do. The first motor we ever ran at the kind of speeds we needed for the Airblade lasted 10 seconds before it exploded." Tom Blower, a Dyson design engineer who's probably sick of gags being made about his surname, details the green credentials this new motor brings with it. "It's smaller, but delivers better performance. Doing more, with less. So the Airblade's the only hand dryer that comes with the Carbon Trust's Carbon Reduction label." As Sir James says, refusing to put up with ageing, redundant technology is what drives progress forward. While post-work analysis amongst engineers in their local, The Smoking Dog, would be of scant interest to most of us, we're the ones who end up benefitting from their discussions. One question, though – why doesn't The Smoking Dog have an Airblade in its toilets? "Mm," says Bernard, smiling. "We should probably do something about that."