Fläkt Woods has raised the bar for fan manufacturers worldwide, utilising turbo-machinery technology it has achieved landmark EN12101-3 certification for 400°C for 2 hours (F400) on its range of large axial fans up to 2.8m in diameter by successfully testing a fan 1MW 1,500 rpm, 2.24m in diameter.
The test of the Fläkt Woods fan with steel blades and steel hub is a significant development in fan technology.
Tested at the TST facility in Spain, the 2-hour test at 400°C is in accordance with the requirements of EN12101-3. The test was witnessed by representatives of Cobra and 2IT Engingenieria, Spanish civil engineering companies.
While the largest of the fans from the new range are used in tunnel and metro application, with the 400°C requirement being driven by a need to operate in the event of increasingly large fires, the certification has important implications for fans used for retail as well as office uses.
Increasingly, fire designers and engineers are raising the boundaries of fire standards, so fans have to operate at ever-higher temperatures. Previously fans were considered safe if certified for 300°C for 2 hours, but now the market is moving towards a need for 400°C for 2 hours.
This test on the most highly stressed example in the range, with the greatest power requirement allows for a complete range of fans to be certified up to 2.8m diameter. Presently, there is little actual requirement for a 1MW example, but Fläkt Woods recognise that the boundaries are ever increasing, so this is looking to the future in range terms. Generally the fan size in a tunnel or metro application is increasing. It is also believed that Fläkt Woods is now the only manufacturer to have successfully tested a 2.24m diameter fan, running at 1,500 rpm, with a 1MW motor.
The increase in speed from 1,000 rpm (6-Pole) to 1,500 rpm (4-Pole) is significant as it allows additional pressure development. Additional pressure development enables the 2.24m diameter fan at 4-Pole speed to be used in applications were designers might previously have specified a two-stage fan. A single stage fan will always be lower cost than a two-stage fan at a specific duty point, and as such the 2.24m diameter 4-Pole fan can be a more competitive solution.
Commenting on the success of the tests, Geoff Sheard, Fläkt Woods' Vice President Fan Technology, said:
Designers are increasingly specifying for larger and larger fires, and so although in the past a fan that could operate during an emergency clearing smoke at 300°C for 2 hours was acceptable, today, we see more and more designers demanding fans capable of operating for 2 hours at 400°C. This new range of fans that we have certified is not a development of a historic product range. This is not an incremental improvement on what we have done in the past and is not based on traditional fan technology. This new range of fans is based on turbo-machinery technology and is therefore a quantum leap in fan engineering.