Fire, Smoke and Weather Sealing for Door Assemblies
What's the difference between a brush smoke seal and one with fins?
Brush seals were the first on the market (in fact, Lorient were the first to introduce them, back in 1979!), and hence they have popular appeal as the traditional smoke seal solution. Although they are still effective as smoke seals, the Building Regulations have moved on since they were introduced, most notably with new requirements in the last few years for doors to provide acoustic containment, and also be easy to operate to allow access for all. With so many doors now needing to conform to these new requirements, the brush-style smoke seal is simply not up to the challenge any more. Brushes are particularly poor at providing acoustic containment, as the brush fibers allow air to pass straight through, and therefore sound too. They also provide plenty of friction, which makes doors more difficult to operate.
Fin-style seals provide a much more modern, comprehensive and indeed hygienic solution. They have better acoustic containment properties (particularly ones with dual fins) and much lower frictional resistance.
It's important though that the fin seal remains continuous around ironmongery for both acoustic and smoke containment - but this can be a challenge if the seal has centrally positioned fins. Offset fins make this much easier. This is why Lorient have introduced the DS and Finesse™ seals, with offset dual fins, for a complete acoustic, smoke, fire and low-friction solution.
The durability of some fin-style seals has been questioned in the market at times - but Lorient have extensively tested the DS, cycling it 1,000,000 times (10 times the usual industry level) on a full-size door assembly, without failure. As long as the seal is correctly installed, and the doors are suitably maintained, it will provide years of reliable service. The Finesse™ seal has been similarly tested too. It's unique in the industry, as its fins start at the base of the product and wrap around the sides of seal, both helping to hold it securely in place in the groove, and provide extra durability.
Please refer to the product pages highlighted for more information.