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ENERGY
Building Design Massing and Orientation In winter, insulation will be crucial. The large expanses of glass should be covered at night to avoid radiative losses. The benefits of glazing for solar gains in winter will be limited to the S, SE and SW. The ancillary office areas are not ideally orientated with regards to the summer solar path. The area in which solar gains will be most critical, the offices (sedentary occupation in combination with high internal heat gains from computers). Ideally, this space would be oriented along the E-W axis, to minimise the Westerly exposures (lower-angle, afternoon sun in the summer, the hottest time of the day).
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Vertical Shading
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6pm
If current orientations are maintained, solar shading should be provided, ideally according to the sketch opposite. A natural ventilation/ cooling strategy for the offices could involve stack ventilation with a negative-pressure device which can be integrated with shading:
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Shading With such high levels of solar radiation at the site of the new Music Centre solar control is vital if it is desirable to eliminate or reduce the need for mechanical cooling or air conditioning.
Prevailing summer wind
By the use of external shading devices such as overhangs or vertical finned elements we can shield the internal space from receiving excessive solar gain and therefore maximise the amount of glazing in the faรงade to improve daylighting and occupant well being.
Summer sun path 12pm 3pm
9am
Winter sun path 12pm
Prevailing winter wind
The Israeli Vocal Music Centre Initial Environmental Considerations
ENERGY
Sustainable Design Daylighting
Thermal Mass The use of heavy weight materials in the building is paramount in the design of a naturally ventilated building in this climate. Heavy weight materials provide levels of thermal damping so that the building fabric can absorb heat during hot summer days. With carefully designed night-time ventilation strategies the building fabric is then cooled down at night when the outdoor air temperature is much lower.
North facing rooflights to the auditorium spaces can provide excellent levels of daylight to the space whilst limiting solar gain. These rooflights should be adjustable so as to control levels of daylight in the space below and to even go as far as complete blackout if so required.
Summer sun
The positioning of these rooflights should also be coordinated with the acoustic design for the space so as to eliminate any ingress of external noise and to also control reverberation during a performance.
The cycle then begins the next day when the ‘coolth’ stored in the slab from the previous night is released into the space providing a method of free radiant cooling. Concrete has an excellent thermal capacity however the processes involved in producing it is quite carbon intensive. Other similar materials with a lower carbon footprint would be compressed clay, local stone or masonry or even concrete made from recycled aggregates.
High level outlet for stack ventilation
Ventilation The ventilation strategy should be designed around the thermodynamic properties of air. The use of the stack effect to draw cool air in at low level and exhaust warm air out at high level should negate the need for a mechanical fan for portions of the year. The use of a thermal labyrinth should provide thermal damping and additional thermal mass to the building which should generate generous amounts of free cooling to the occupancies. The intermittent use of the Music centre should give ample amount of time for the labyrinth to re-charge with coolth before the next day or night of performances in the large auditoriums. The delivery of fresh air to the auditorium spaces at low level maximises the cooling effect of the air and ensures a rapid expulsion of stale air upwards and out of the building. The buoyancy of the warm air as it rises provides a free method of exhaust without the need for a mechanical fan. However, if need be this high level air could be re-circulated by the use of a mechanical fan for the purpose of recovering heat during cooler months of the year. There may also be an advantage of re-covering heat during the summer during periods when the exhaust air is still cooler than the warm outdoor air.
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Winter sun
te pro g ldin sun Bui the from
Skylight for natural ventilation
Consider letting fresh air into the building at low level Evaporative cooling from trees and plants
Thermal mass on all floors and use of a thermal labyrinth
The Israeli Vocal Music Centre Initial Environmental Considerations
ENERGY
U-Values
Evaporative Cooling
Heating
Construction build-ups are crucial to making a low energy building work. By specifying construction details with low U-values the building fabric heat transfer can be reduced in turn reducing internal space heating load and also reducing the internal space heat build up during the summer.
As warm air passes over external water features and green landscaping the air will be cooled adiabatically by the evaporation of water. This cool air will pass inwards to the building by wind pressure velocities and provide a fresh airy feel to the atrium.
With efficiency measures in place and the inclusion of heat recovery it should be possible to eliminate the need for space heating in the building. The mild winter conditions give opportunity to do this but only if certain design features are detailed out.
Adjustable building elements may be vital in the Music Centre. The roof for example could favour low U-values during the winter or when the occupancy is low but during periods of high occupancy and internal space heat gain the roof might favour higher U-values so as it can lose heat faster to the environment.
Summer sun
Adjustable roof skins can be designed in the form of transparent materials which can also adjust to control light levels in the space.
The internal space gains of the occupants during a performance should provide sufficient space heating during a performance. Heat recovery to the ventilation strategy can then be used to re-circulate warm air back into the occupied spaces. Any waste heat during this mode can be dumped into the thermal labyrinth so it can be utilised as a thermal store. This stored heat can then be called upon during times of lower occupancies in the winter when there may be a space heating demand.
Glazing With high levels of glazing included in the scheme particularly to the public spaces the selection of glass is very important. We do not wish to compromise the ethos or form of the architect’s vision so with careful selection of the appropriate glazing type we can still maximise daylight, view factors, and maintain a level of transparency but also reduce solar gain through the façade. Solar control glass can come in various levels of performance, unfortunately the higher performance glass is often tinted which does effect colour rendition. This type of glazing is more suitable for the east and west facades as it will help eliminate the discomfort brought about by glare from the low angle sun. In the South however glare is less of an issue and it is important to give occupants a sense of wellbeing by optimising daylight and giving them a sense of transparency through the glass. Therefore a more neutral glass type is more appropriate here. (With the correct level of solar shading of course) With such high levels of glass to some of the facades the use of a ventilated cavity could be employed to act not only as a buffer to the building fabric but also as a means of cooling the glass and taking away some of the internal space gains.
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Winter sun Evaporative cooling from trees and plants
Double skin of glass to allow for a ventilated cavity. Solar control glass should be used on the inner skin to prevent excessive solar gains
The Israeli Vocal Music Centre Initial Environmental Considerations
Potential for cross ventilation Thermal mass to help regulate the internal temperatures
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The Heder Architecture
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