The best ideas are usually the simplest. Recognising that vacuum insulation in Thermos flasks is a great way of insulating the contents, it is a simple step to advocate vacuumbased insulation for other applications. Unfortunately, the simplest ideas are rarely the cheapest, and this is one of the reasons - notwithstanding the exacting production standards - which have meant that vacuum insulation has not really taken off in the construction industry.
However, given the imminent arrival of Part L, Stephen Dench of Visionary Architects believes that the time has come to apply this idea to external cladding systems. He has been granted a patent on his 'invention', called 'the energy saving vacuum panel system'.
The panel comprises two layers of a solid grid-structure of square-section lengths of EPDM, separated by similar EPDM spacer bars to form a framework. This volume is overlaid by an 'outer skin' to form a sealed unit. The unit is sealed, save for a nozzle-feed from the internal void to the outside which is attached to a pump.
At present, there is no prototype to assess the physical sizes of EPDM members, nor thickness of the skin which will be required to self-support the panel and to withstand the pressures of evacuation of the internal volume, without buckling or even distorting the external skin. Similarly, no tests have been carried out to quantify whether leakages will require top-up intervention of the pumps, via permanent plenum feeds (a similar process - but in reverse - to that of the ETFE inflatable roof 'pillows' at the Eden Project).
The panels are designed to be fitted into a curtain wall-type situation, fitting the panels between thermallybroken mullions. Theoretically, says Dench, 'the panels can provide a Uvalue of 0.001W/m 2/K' and will have excellent sound-attenuating properties, 'of 90-120dB'.
Dench, who studied at Hull School of Architecture, won a scholarship to the Bauhaus in Dessau and worked with FaulknerBrowns in Newcastle, was also an architectural technician for five years. The idea of vacuum-packed cladding has been a dream of his for many years.
'Buckminster Fuller's dome over Manhattan, Erskine's Arctic projects, Paolo Soleri's work and the Columbia University's Biosphere 2, led me to think that a totally sealed buildingenvelope shield would enable energy efficient architecture to be considered in any climate, ' he says.
Dench recognises that he desperately needs to get the scheme off the drawing board and is searching for a partner and funding agency. As with most early-stage innovations, the current status of technical detail leaves a lot to be desired and a lot of criticallyappraised and peer-reviewed work needs to be done urgently. But if satisfactory funding for prototypes and technical trials is found, if a coherent professional team can rationalise the various elements, and if realistic aspirations can be made for its phased application, this could be a significant idea in the making.
For more information contact Stephen Dench, Visionary Architects, tel 020 8940 7769
APPLYING FOR PATENTS
The process of applying for a patent is as follows (although we recommend that individuals contact the Patent Office for specific details):
Provide a full description of your 'invention'on a standard form, and receive your application number and a record of the filing date.Unless already provided at the original filing date, file your claim and request a search (for a fee of £130) within 12 months.
Any objections need to be responded to within the time specified in the search report and, if this is cleared, the Patent Office will publish your application after 18 months.
Within six months of publication, request an examination (fee £70) and reply to the resulting examination report within the time-limit stated therein.
Elements of this process may be repeated (for up to four-and-a-half years) until your application is agreed, at which time the Patent Office grants a Certificate of Grant.
Renewal fees of £50 per year (rising to £400 in the 20th year) are then payable.
Contact the Patent Office to request its free pamphlet, The procedure for granting of a UK Patent. Tel 08459 500505.
From 1996 to 1999, the number of British patents registered rose by 23.9 per cent, from 3,339 to 4,138.The total in the US rose by 35.7 per cent to 25,333; there was a 51.4 per cent increase to 18,190 in Germany and in Japan the rise was 28.7 per cent, from 11,357 to 14,617.
Data from the Design Council