Research, Development and Demonstration of Microprocessor-Controlled Sunspaces with Air-Circulation, Passive Ventilation, Shading and Insulation Systems as a Device for Energy Efficient Heating of Buildings

摘要

Utilisation of solar energy has been absolutely vital for man, animal and plant alike from the dawn of time. Historic cultures, like the Greek, are known to have utilised passive solar energy in buildings in a more sophisticated way to sustain a relatively comfortable life style. One of the best-known historic passive-solar-architecture settlements is Olynthus, constructed around 400 BC. The Greeks understood to construct dwellings that were orientated and designed to maximise passive solar gain during the colder months of the year and to prevent overheating during the summer time. It seems that this development was supported by legislation that guaranteed the right to unobstructed sun exposure. Apparently it was not allowed to locate a site for a building that would cause shading to another. Later these techniques were forgotten and during the 20th century architecture underwent a dramatic revolution due to the discovery of new technologies and the availability and perceived abundance of fossil fuels, leading to building design with diminished consideration to integration and utilisation of environmental factors. The era of such architectural freedom is now being challenged. Economical and ecological pressures indicate that the current situation is not sustainable. For some advanced designers this has led to experiments in architecture and building management systems. Obviously, when ambient local factors receive more attention, a building and its construction will have to be assessed in, and relative to, its environment. Ireland has a very mild but damp climate compared to most other European countries; factors that will have to be kept keenly in mind when comparing building techniques and introducing measures to increase sustainability. McNicholl and Owen (McNicholl and Owen (1996), "Green Design (Sustainable Building for Ireland)") state, "The renewable with by far the greatest potential to meet energy needs in Irish buildings is passive solar energy. Our temperate climate and surprisingly high level of solar radiation mean that a substantial percentage of the fossil-fuel based energy currently consumed by building services could be displaced." They further suggest creating buffer spaces in buildings by locating cool rooms on the north side of a building and by placing unheated conservatories or sunspaces on the south. Predictions of the expected gain from such measures are not made, most likely because of the great number of variables affecting the performance of conservatories etc. However, the authors claim, "during the heating season a south-facing sunspace or conservatory will collect solar energy and, by acting as a buffer space, reduce heat losses. It can also be used to preheat ventilation air. This can be a substantial benefit. Raising the air temperature from 4°C (outdoor temperature) to 12°C, for example, can halve the ventilation heat load. It is essential that the sunspace can be closed off from heated areas of the building when necessary."