To demonstrate the potential of unheated covered streets in educational establishments by reducing the annual energy consumption in the main circulation and amenity spaces in part of the new Dublin City University (formerly the National Institute for Higher Education, Dublin) complex by the use of unheated "glazed" sheets.
The construction of the street has not encountered any major difficulty. The only real point of difficulty has been in the design of a smoke ventilation system for the covered street. The planning permission stipulated that this should comply with the Greater London Council's Technical Information Note - "Fire Safety for the Atrium". This note stipulates that, where smoke extraction is to be by natural means, then automatic smoke vents shall be installed on the roof and shall comprise an area of 10% of the floor area, and that en equal area of low-level automatic inlet ventilation shall be provided. In the opinion of many specialists in the field, this stipulation of 10% of floor area lacks any scientific basis and the areas required for extract vents and particularly inlet vents are higher than would be required using any of the modern design methodologies.
In order to avoid possible delays, however, it was decided to comply with the Planning Permission as written.
The monitoringsystem was installed in 1989 and monitoring commenced in November 1989. Analysis of the data is ongoing.
NIHE is building a major extension to its existing facilities on a 40 hectare site. The development consists of a number of long, shallow plan, 3 floors high buildings 8.1m apart. Streets formed between the buildings would be enclosed by glazed roofs end walls, and interconnected by links through the ground floor level of buildings at their ends.
The complete development is divised into 3 stages: this project is however, confined to the first 2. The first stage consists of an office block and library: the area between these two will be a glazed street of 8.1m in width and 11m height to apex. Phase 2 buildings will have streets of similar width, widening out to multiples of 8.1m in some areas, have a pitched glazed roof of 13.5m height to eaves and 16m to apex. The street roof and end walls would be sealed by clear double glazed units.
The unheated streets would normally be at a temperature higher than outside due to heat gains from adjacent building occupancy, lighting and solar gain. Street facing walls will be constructed as internal walls thus saving on building fabric costs while still achieving a reduction in energy consumption.
Street temperature would be sensitive to air movement between the street, adjacent buildings and the outside. A number of simple methods for controlling air movement are being considered with a view to achieving a good balance between heat recovery, simplicity of operation and capital cost. Glass covered street area is 14% (5,800m2) of total (51,000m2) proposed floor area. Street heat gains from adjacent buildings plus solar gains through the glazing will be transfered by a series of small modular roof mounted air handing units drawing air from the street.
The project, in 4 phases, commenced 8/11/85 and will end December 1990 at a total cost of IRL 13,433,000.