Press Releases

New Cladding Panel
Architect, Steve Dench, has patented a photovoltaic vacuum cladding panel after five years of research and design development. His new invention has photovoltaic cells on the external face and acts as a shield with almost zero thermal U value. Surrey-based Dench, a sole practitioner trading under the name of Visionary Architects, also aims to market the panel for insulating domestic and industrial products such as refrigerators and vehicles. He is talking to manufacturers about the potential of the product and hopes to set up a series of prototype projects at the National Physical Laboratory in Teddington, Middlesex.
The Architect's Journal (14 June 2001, p. 10)

Steve Dench's solar power cladding panels
Architect, Steve Dench, has developed and patented a solar energy-generating cladding panel with a U-value close to zero. The panel works on the same principle as a thermos flask, with a vacuum inside the panel that prevents the transmission of heat and sound. EPDM rubber, an excellent insulator, separates the two skins of the panel, which will be only 30-35mm apart.

The panels are designed to fit within standard cladding systems, and Dench envisages other potential markets, including fridge insulation, because the system's compactness increases the internal volume available. The National Physics laboratory in Teddington has made positive noises about the system and Dench is in talks with two parties interested in taking the idea forward. He is hopeful that further testing can be carried out later this year if funding becomes available and that the system will be on the market within the next couple of years.
Building magazine (27 July 2001, p.59)

Progress is patently pending
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 vacuum-based insulation for other applications. Unfortunately, the simplest ideas are rarely the cheapest, and this is one of the reasons - not withstanding 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 thermally-broken mullions. Theoretically, says Dench 'the panels can provide a U-value of 0.001W/m2/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 Desau 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 building-envelope shield would enable energy efficient architecture to be considered in any climate.

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 critically-appraised and peer-reviewed analysis 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.
The Architect's Journal (6 September 2002, p.39)