SOLAR THERMAL TECHNOLOGIES

Buildings contribute highly to CO2 production Big Differences between countries as a function of climate and living standards Growth is linked to energy demand. However recent technologies permit to disassociate …...

Solar and Energy Efficient technologies have penetrated to the market.

Solar buildings rely on both traditional,energy conscious architectural practices and very recent developments which supply architects and building engineers with an ever-increasing catalogue of components and concepts Such as advanced windows and better insulation materials, solar cells and collectors, heat pumps, daylighting, integrated lighting and shading control systems, free nocturnal air cooling, pre-heaters like air heat recovery and air-to-ground heat exchangers for preheating in winter and cooling in summer, phase change materials..., just to name a few examples. Some concepts convince through their simplicity, others impress by their technical fineness. New powerful simulation methods allow architects and engineers to model the interplay between these components in the design phase of a building.

Tremendous improvements on transparent materials

New Advanced Cooling Systems and Techniques

Massive Use of new Technologies decrease the cost

Solar Houses may be economically optimized

and do not present any additional cost

New Designs have decreased the heating demand as low as 15 to 30 kWh/m2/yc

New Designs have decreased the cooling demand as low as 5 to 10 kWh/m2/y

A serious trend to decrease the energy consumption

Future developments The problem of energy and global environmental quality of buildings is complicated and should not been seen as isolated phenomena. On the contrary it has to be studied in relation to the problems of indoor and ambient environmental quality.

Future developments 70 % of the energy consumption of buildings is spend in urban environment. In particular the thermal and optical phenomena as well as the air quality in the urban environment determine, almost completely, the energy consumption as well as comfort and quality conditions in buildings. Recent technological developments on the field of solar energy in buildings including passive heating and cooling techniques as well as daylight systems, permit to seriously decrease the energy consumption, improve thermal and visual conditions in buildings as well its indoor air quality. However, there is a lack of knowledge on the optimum integration of these techniques in urban buildings

Future developments Application of passive solar systems and techniques and in particular of the cooling techniques while are well known and scientifically comprehensible under undisturbed conditions, present important problems when have to be used in cities and incorporated in urban buildings. mainly because of : a) The dramatic variation of the energy potential of the sources and sinks, (i.e.. air movement).b) The restrictions because of the urban limit conditions. c) The particular climatic phenomena, (I.e. pollution).

Future developments Energy spend by new constructions is less than 1 % of the total energy consumption of the building’s sector. Problems of high energy consumption and not appropriate indoor air quality are mainly presented in old and medium age existing buildings of specific characteristics. There is a need for a more concrete knowledge of the specific energy consumption of each building sector as well as of the specific energy targets by type of building.

Future developments There is a need to further develop appropriate methodologies to evaluate from the technical and economical point of view, the possible retrofitting scenarios of urban buildings as well as a need to develop labeling methodologies

Future developments A European frame program to investigate and develop solutions to decrease the rapid penetration of air conditioning is absolutely necessary