Making Buildings Safer
FläktGroup subsidiary, Fläkt Woods, has chosen Danfoss HVAC VLT® variable speed drives (VSDs) for its new high temperature fan/VSD range.
Packaged solutions in the range comply fully with EN12101-3:2015 which came into effect on 8th April 2017 and offers three options for the control of fans that must continue to operate during fire events. These are to use a fully tested and certified high temperature fan/VSD package, to bypass the VSD controlling the fan motor during fire events, or to de-rate the fan motor by 20 per cent and fit a voltage waveform filter. Whilst they could already offer the second and third solutions, Fläkt Woods considered that, in most applications, the first option would offer significant benefits in terms of increasing building occupant safety.
Andy Cardy, product manager for Axial Fans at Fläkt Woods, says:
“Bypassing the VSD during a fire event means that the fan must run at full speed, which makes it difficult for designers to implement their required smoke control and extraction strategies.
"And using a non-certified fan/VSD package means fitting an oversized motor and an expensive filter that may well cost more than the VSD. With all of this in mind, we decided to go ahead with developing a tested and certified fan/VSD solution."
For the VSDs and advice on motor selection, the Flakt Woods called on the resources of another acknowledged leader in its field, Danfoss Drives. The decision to work with Danfoss was based on the company’s outstanding reputation for innovation and product quality, its extensive experience in the HVAC industry and its supportive approach to helping achieve the goals of this important project.
Engineers from Danfoss worked closely with their counterparts from Fläkt Woods for more than two years, investigating and evaluating all of the permissible options for controlling fans during fire events. Ultimately, they developed the package solution comprising Fläkt Woods fans and Danfoss VSDs with operating parameters specifically selected for this demanding application. After the development work had been completed, the finalised product offerings were subjected to rigorous third party testing at BSRIA, as required by EN12101-3:2015, with the Danfoss engineers continuing to provide support throughout the test period.
The success of the testing programme has made Fläkt Woods the first company to bring a certified fan/VSD packaged solution to market, with Cardy adding:
"We see this as an important breakthrough in building safety because knowing that they will retain full control over fans during a fire event gives designers many more options for efficient and effective smoke control.
"We are, of course, very pleased to have achieved certification for assemblies that include our fans, but we’re happy to acknowledge that the HVAC VLT® VSDs from Danfoss Drives are also a crucial component of the package. In a nutshell, the success of this important project is the result of the happy marriage of products from two companies that are equally committed to safety, quality and innovation."