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The Future of Operating Theatres – Howorth Installs New Screenless UCV Canopies at Southmead

2 October 2012

A 21st century operating theatre needs to allow for flexibility of equipment choice and changing work practices, but also to look sleek and streamlined.  This was what Southmead Hospital, part of the North Bristol NHS Trust, wanted when it was fitting out 16 new operating theatres as part of a recent major PFI re-development, and Howorth Air Technology’s new Screenless Exflow Evolution ultra clean canopy met the brief perfectly.


The Trust had seen screenless canopies being used in other European countries, and knew the design offered the benefits it wanted in its new operating theatres, primarily future-proofing and flexibility of use.  When main contractors, Carillion, initially approached Howorth, the company did not offer a screenless option, but determined to design one especially for the project, which would out-perform anything else on the market.  The decision to use screenless canopies was made late into the build programme, so the fact that Howorth’s design did not require bulky low-level recirculation ducts made it particularly attractive, as the design offered by competitors’ products meant installation would have been very disruptive on site, as well as requiring a major redesign of the theatre.


Carillion waited for Howorth to complete design and testing of the screenless unit, now called the Evolution, which was witnessed and approved by the Trust and Carillion in January 2012. Installation is due to commence in October, with project handover in late 2013.


The Evolution retains the basic construction of Howorth’s existing models, the Exflow 28 and 32, but some innovative engineering at the air discharge means that the system’s performance has been recreated and in many way improved, without the need for the traditional partial walls, or the additional requirement of potentially bulky low level recirculation ducts, remote fans or chilled water cooling coils that many competitor models require.  This means the systems is also suitable for retrofits as well as new builds.


At the system’s core are patented Passive Coanda and Active Coanda systems, designed to replicate the controlled airflow of a solid side screen.  The Evolution has been independently validated, and found to exceed the performance requirements of HTM 03-01, particularly with regard to the non-entrainment test.