CALMFLOOR® damper for amazingly easy office to lab conversions

Written by Aleksandar Pavic.

FSD Active’s new CALMFLOOR® damper is rapidly garnering interest from architects, engineers, and property developers alike, all keen to maximise its benefits for their own varied applications. We demonstrated recently how CALMFLOOR can revolutionise the existing design concept for a typical high-frequency ‘laboratory floor’. CALMFLOOR dampers can enable standard low-frequency suspended floors, normally used for commercial premises such as offices, to provide a suitable environment for a typical life-science laboratory, in spite of the significantly more stringent vibration response factor (R) of R<2 or less than 8000 mips root-mean-square (RMS) in the North American practice. In practical terms, R<2 means that the floor feels solid and that human floor occupants will, to all intents and purposes, really not feel much, if any, of the omnipresent walking-induced vibration, as appropriate in traditionally busy laboratories.

Figure 1: Top – Response factors for a standard steel-concrete composite office floor featuring very long spans over 16m floor. Maximum response factor over 10. Bottom – Response factors for the same office floor with 13 CALMFLOOR units placed at floor vibration ‘hotspot’ areas. Maximum response factor reduced to below 2.

Results from detailed FE modelling and vibration serviceability simulations of a standard low-frequency office floor with an area of over 3000m2 and spans of over 14m are presented Figure 1 (top). This contour plot shows that when subject to human walking, response factors potentially as high as 10.7 could be reached. This is well in excess of the limit of R<2 with around 20% of the floor area failing the criterion i.e. has R>2 , typically around mid-spans.

However, with only 13 CALMFLOOR dampers distributed strategically throughout the floor at vibration ‘hot spots’, the floor’s maximum response factor reduced over 5 times to within limits of R<2  – see Figure 1 (bottom) contour plot of R factors with CALMFLOOR locations indicated by violet diamonds. No structural modification whatsoever would be required to accommodate these 13 CALMFLOOR (Figure 2) dampers weighing only 70kg each. No other vibration control solution commercially available today could enable such an effective and elegant floor vibration control solution.

This exercise demonstrates nicely how powerful the CALMFLOOR floor vibration control solution is in making sure that a standard low-frequency floor can finally be used to support a standard R<2 laboratory. This is a major achievement and game-changer in lab designs enabled solely by the novel floor AMD technology. CALMFLOOR eliminates the need for heavy, deep, short span, and high-frequency floors which would typically be otherwise required to facilitate R<2 laboratories. The common design approach today requires disproportionately large amounts of the embodied carbon of well over 1,000 kgCO2e per 1m2 of the standard laboratory floor. This alternative to CALMFLOOR dampers is increasingly being seen in the UK, USA, and elsewhere as simply unacceptable given the climate emergency we now sadly find ourselves in.

calm floor product
Figure 2: Our only 380mm high CALMFLOOR damper attached directly to a web of a composite floor steel I-beam.

In addition to the economic (lighter, thinner floors, squeezing more floor levels within the height restricted multi-storey building envelope, etc.) and accompanying substantial sustainability benefits that CALMFLOOR provides, flexibility for the customer is another key benefit:

  • the number of CALMFLOOR units used can be easily reduced and tailored only to particular locations and level of vibration reductions in them required, in particular, if not the whole of the floor area requires, say, R<2;
  • units can be introduced at will and whenever convenient for conversion of open-plan areas to laboratory usage without affecting construction program;
  • units can be moved around in the future to facilitate another tenant at a much lower cost compared with other options such as Tuned Mass Dampers;
  • units can be introduced after the tenant moves in and precise floor utilisation is known, and
  • units can be removed to restore the office-like floor utilisation if needed.
Aleksandar Pavic

Aleksandar Pavic

Alex’s particular internationally recognised expertise is in vibration serviceability of long-span floors, footbridges and grandstands, which are occupied and dynamically excited by humans. He is also a Managing Director of Full Scale Dynamics Ltd, FSD Active’s sister company of consultants specialised in commercial state-of-the-art dynamic testing, monitoring, design and performance assessment of civil engineering structures.