MCC will improve safety, lower energy and capital costs, providing a more sustainable containment solution
A new concept in containment control for fume cupboards and for broader containment applications was unveiled at the Labs of the Future conference organised by S-Lab in Nottingham.
Presented to delegates by Mike Dockery (Sui Generis), Roy Allwood (Labway Services) and Mark Dawes(Halton Products), the concept of Measured Containment Control (MCC) is said to present a new direction in the control of laboratory containment devices which improves safety, lowers both revenue (energy) and capital costs, and represents a more sustainable design solution.
Dockery said: 'The ventilation rates of lab containment devices have traditionally been set on a basis of empiricism and ‘best guesses’. Sustainability has been addressed by the replacement of constant volume control with Variable Air Volume (VAV) although this in itself introduces further predetermined estimations that can adversely affect safety performance.
'Alternative and objective control approaches are now available that seek to overcome the deficiencies of more traditional systems.'
The basis of MCC is that VAV control can be more effectively achieved, in terms of both safety and energy efficiency, by means of direct measurements of contaminants within fume cupboards.
This principle typically uses VAV modulating dampers that are controlled by signals from contaminant and/or condition (e.g. volatile compounds or particulates) sensors in the exhaust duct connection, with optional readings from within the fume cupboard itself.
By means of continuous measurement of contaminants, MCC will permit the effective use of turndown ratios of 10:1 or even higher compared to the more traditional VAV ratios of 3-4:1. When a fume cupboard sash is a fully open for set-up activities (clean conditions) a conventional VAV installation is likely to be exhausting at its maximum rate, whereas MCC will operate at maximum turndown.
In the event of an incident in a fume cupboard involving a major release of contaminants the natural response of a user is to close the sash whereupon a conventional VAV installation will reduce the exhaust volume. In such circumstances it is frequently reported that fume escapes into the lab, particularly when over-optimistic turndown ratios have been used.
MCC will automatically do the opposite in terms of exhaust volume (going up to a maximum) and will dramatically improve containment and safety.
A further consideration is that, while dependent on individual operating conditions, it is estimated that the daily exhaust volume requirement of an MCC-fitted fume cupboard is likely to be 25% that of a traditional CV fume cupboard and 50% of the conventional VAV equivalent.
This step-change in ventilation demand is being achieved while improving safety since hazards are being effectively and continuously monitored.
There is also the potential to expand the concept to other containment devices such as isolators and more.
ContainAbility, a venture recently set up by Dockery and Allwood, seeks out partners with which it can work to introduce new thinking and innovative solutions. Allwood said: 'MCC is one such development and our strategic partner for the development of this concept is Halton.'
Founded in Finland, Halton has developed ventilation systems and controls for lab and containment devices for many years, including conventional fume cupboard VAV.
Successful testing of prototypes has already taken place at the Halton Innovation Hub in France and intellectual property protection has been put in place with a patent pending.
Dawes said that the speed of response of the system under prototype testing at Halton’s French facility exceeded expectations: 'It was virtually instantaneous from the first release of contaminant', he said.
He added that other benefits of MCC will include extensions to the operational life of filters used in containment devices and a reduction in the numbers of (potentially hazardous) filter change operations that are necessary.
The system will also be available for retrofit to existing labs. Dawes added prototypes are currently being produced and refined and will undergo rigorous testing before being launched next year as part of the Halton Vita Lab range under the product name VLM.
It is expected that product specific details will be released at S-Lab's next annual event in York in Summer 2017.