2003 IRISH SCIENTIST YEAR BOOK

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University of Ulster
Philip Eames
Centre for Sustainable Technologies
The Centre for Sustainable Technologies (CST) undertakes both applied and fundamental research in the areas of Solar Energy and Energy in Buildings, River Hydraulics and Hydropower, and Sustainable Materials and Processes. Research work is undertaken in collaboration with industry, research establishments and other university research groups in Ireland, the UK, Europe and worldwide.

Current research in the area of advanced glazing includes two Engineering and Physical Sciences Research Council (EPSRC) funded projects - 'Fabrication of Durable Edge Seals for Cost Effective Evacuated Glazing' and 'Vacuum Window Design Optimisation and Thermal Comfort Implications', and an EU-funded project 'Electrochromic Evacuated Advanced Glazing' - ELEVAG.


An example simulation of phase change materials used to reduce temperature rise on the front surface of a finned container.

A patented edge sealing technique developed at the University of Ulster permits the production of high performance low heat loss evacuated glazing at temperatures of less than 200�C. The low temperature of manufacture allows both tempered glass and high performance silver-based low emittance coatings to be used in manufacture. Maintaining a vacuum of less than 0.1 Pascal in the sealed unit permits mid-pane U-values of down to 0.6W/m2K to be achieved. The three research projects seek to:

(i) determine the optimal means of cost-effective vacuum glazing production to provide a glazing life/durability of over 20 years
(ii) examine the performance of installed vacuum glazing with particular emphasis on building occupant comfort and the effects of real conditions on system performance
(iii) develop and characterise a combined electrochromic evacuated glazing to give a very low heat loss glazing that can be switched from transparent to opaque.

Research in the area of building integrated photovoltaics is supported through the EPSRC funded projects 'Improved Solar Cell Performance in Building Integration' and 'Demonstration of a Quantum Dot Concentrator', and an EU-funded project IDECONTE. Using non-imaging optics allows low levels of concentration of solar radiation in the range of 2 to 2.5 to be achieved without a system tracking requirement, thus making systems ideally suited for static building fa�ade mounting. Both reflective and refractive dielectric asymmetric concentrator systems have been designed, fabricated and characterised. For monocrystaline silicon a 10�C rise reduces solar to electrical conversion efficiency by approximately 5%.

Three methods to minimise this temperature rise for building integrated concentrator systems have been investigated:

(i) the use of phase change materials integrated into the photovoltaic (PV) panel
(ii) the use of enhanced natural convection to remove heat
(iii) the potential of developing spectrally selective films to reflect wavelengths of light not utilised by the PV.


An example simulation of air flow and temperatures for a concentrating building fa�ade integrated photovoltaic system.

Using ray trace models for optical behaviour prediction and computational fluid dynamics models for simulation of combined heat and mass transfer (developed in-house and extensively experimentally validated over the last 16 years), detailed theoretical analyses have been undertaken and indicate that for the UK climate it is possible to maintain PV temperatures below or at the characterising temperature of 25�C for most of the year.

Phase change materials permit large amounts of energy to be stored at a pre-determined temperature in a more compact space compared to sensible energy storage. In an EU-funded project, PAMELA, phase change materials are being micro-encapsulated by BASF so that when in a suitable carrier fluid they can be pumped in a similar way to water with a much greater heat carrying capacity at a set temperature per unit volume. Detailed theoretical models and large scale experimental systems to determine real performance for heating and cooling in buildings and solar thermal applications are being developed at the University of Ulster.

Contact: Professor Philip Eames School of the Built Environment, University of Ulster,
Newtownabbey, Co Antrim BT37 0QB;
Tel: 02890 368244; Fax: 02890 368239; E-mail: [email protected]