Personal printers are grossly inefficient compared with network printers - burning extra power which dwarfs the toner bill and bloats companies' carbon footprint, according to Dell.

The company claims personal laser printers cost €85 per year in power costs alone, compared with €5 per user each year for a networked printer. Users continue to provide them because they are simply unaware of the costs involved, says Dell's research.

Seventy-nine percent of IT managers simply don't know the cost of running their printers, according to a Dell survey of small-to-medium businesses in the UK, France and Germany. Ninety percent of managers don't restrict printing in any way, and more than half of them (58 percent) don't even know how many printers they have in their organisation.

"There are thousands of personal printers out there, because IT staff feel people need them," said Stephen Burt, Dell's European imaging business manager. Around 40 percent of these in business are personal laser printers, he said which are power-hogs: "The power costs are much greater than the toner costs."

Laser printers are inefficient when they are lightly used, because the drum mechanism is kept hot for half an hour after each use, in case of further printing, he said. A group of thirty users with personal mono printers will use 17,000 kWh of power per year, costing €85 per user, he said - figures which assume three hours printing each day, and the power consumption of a comparatively efficient modern laser such as they Dell 1110.

A single networked printer could replace all thirty personal printers and print the same number of pages for only 1,000 kWh per year, which works out at €5 in power costs. Consumables would also cost less for the networked printer.

Centralised printing could also manage the arrival of colour lasers, which are now becoming cheap enough to use across the organization, said Burt. Networked printers are more likely to have controls that can ration colour printing to certain users, so it is used where it will be effective.

Currently at number eight in printer market share in Europe (and number six in colour lasers) Dell hopes economy and efficiency measures will move it up the league table. Higher placed manufacturers such as HP are often felt to be focusing on selling more ink and toner.

Comparing efficiency of colour printers could become easier with the arrival of new ISO standards to compare printer yields, including ISO 24712, a set of colour test pages. "You can now compare colour printer yields between vendors," he said. Till now, printer makers have been free to define their own test pages, allowing them to achieve unrealistically high yields.

Lexmark's recent inclusion of Wi-Fi as standard in lower-end printers, is misplaced in devices which are rarely mobile, said Burt: "Ninety-eight percent of people don't use Wi-Fi," he said, asking why the majority should pay for a feature which can add an extra £50 to the price of a printer. Dell offers Wi-Fi with optional USB dongles. "When 98 percent of people want it, it will be a standard."