Sustainable Design Features Of Council House 2 In Melbourne

1. Provide a critical environmental report covering major building performance aspects such as energy efficiency, ventilation, and daylight availability
2. Use calculations methods covered in lectures to analytically evaluate the performance of specific design strategies or the building performance

Building Description

Council House 2

Council House 2 occupies a floor are of 12500 m2 and was constructed at a cost of $51 M.

Construcion materials: Pre-cast concrete, timber 

Ground Floor Plan 

Section 

Section 

Elevation 

Bioclimatic Section-Night

The climate of Melbourne where the building is located is subtropical oceanic and has pleasantly warm summers as well as mild winters. The weather is mostly variable owing to the fact that the city is situated enough to the south to be influenced by the flow of the westerly winds that bring low pressure systems for numerous months a year (Afram and Janabi-Sharifi, 2014). 

Rainfall is not as abundant in Melbourne as it adds up to 650 ml which is about 25.5 inches even though it is properly distributed over the seasons of the year in such a way that there is no real dry season. Nonetheless, the least rainy season is often experienced during summers. 

In as much as it is having mild climate, Melbourne is often subject to swings in climate since it is reachable by both the masses of cold air from the sea that surround Antarctica as well as by the dry and hot air masses from the Australian desert (Aghemo, Blaso and Pellegrino, 2014). The winds in the region are often frequent as the westerlies normally blow for the most days of the year while during summer when it is sunny the flow of the sea breeze is often in the afternoon. Not by coincidence, around Melbourne there are numerous beaches frequented by surfers. 

The quantity of sunshine in Melbourne is often better during summer from the  months of December to February when there are quite frequent sunny days while for the remaining seasons of the year the amount of sun is just enough since as has been established there are often weather disturbances. A bit of fog is as well experienced during winter. 

The sea in Melbourne is not often warm and instead cold during most of the times of the year and just gets to 18/19?C between January and March. The summer tends to be slightly warmer in sheltered and closed in Port Philip Bay (Day and Gunderson, 2015).

Council House 2 was designed to be a lighthouse project for new developments of buildings which aimed at influencing the future design to be done in such a way that is more sustainable and efficient. Among the objectives during the design of the building include being neutral in terms of greenhouse as well as enhancing the entire wellbeing of the employees. Various strategies were deployed when attempting to attain this in which the main focus was on sustainability aspect of the building (Garrison et al., 2016).

Climate of Melbourne

Biomimcry formed a greater aspect in the design of the building. The HVAC system was designed with techniques borrowed from a termite mound. In the termite mound, the cool wind was drawn into the mound base through channel and the coolth was stored using wet soil. As the air gains warmth, it tends to flow upwards and off the mound through the vents. This gives the mound the capability to maintain a stable temperature. Council House 2 adopts the same strategies with its systems through effectively making use of natural convection, thermal mass, ventilation sacks, phase change material as well as water for the purposes of cooling (Hong et al., 2015).

The skin system is yet another strategy that is borrowed from nature. The façade of the building is made up of an epidermis which is the outer skin and the dermis which is the inner skin. The dermis of the building is composed of the exterior zone to house the ducts, sunscreens, stairs, lifts, foliage and balconies with the interior line which defines the extent of the compartment of fire. The design of the dermis is done with lightweight constructing with the use of a steel frame. The epidermis offers the micro-environment among them the primary sun as well as control of glare for the building while at the same time forming a semi close micro-environment (Hong et al., 2016). 

The north and south facades of the building have ventilation stacks implemented. The stacks serve to channel air. Since the north stacks tend to receive higher amount of sun, they have been painted black to absorb the extra heat which in turn enhances the rising up of warms air from the building out of the stacks. The south stacks on the other hands are used in the channeling of cold air via the vents. These stacks as well serve to provide shading for the various office windows.

The ceilings have been made from pre-cast concrete that have a wavy shape to optimize the surface areas that in turn enables an increase in the capacity of the thermal mass. During night time, the thermal mass in the concrete is often flushed through a night purge which absorbs the coolth from the night air and thus enabling it to absorb the heat that comes from the space during the day time. The wavy design enables collection of heated air at the ceiling height and thereafter channeling it out of the building into the ventilation stacks (Hoyt, Arens and Zhang, 2015).

Sustainable Design Strategies

Another strategy that used in the design is radiant cooling that has been achieved through running cooled water through the ceiling panels as well as the beams. Chilled panels are able to cool the rising warm air which thereafter drops leading to the creation of a natural convection current. Phase change material has been used in cooling the water for the chilled panels and beams. It adequately assists in keeping the water that is in circulation through the panels and beams at the required and desired temperatures. The phase change material is normally termed as the battery of the building owing to its roles of keeping the coolth.

The orientation as well as position of the building in relation to the surrounding buildings made natural day lighting an uphill task for this project. Another challenge for natural day lighting was the required of a deep open space plan office (Hoyt, Arens and Zhang, 2015). The best design approaches for the building to enable most of the natural light were among them:

• A synergy that was placed between the air ducts and windows size,
• Light shelves which reflected light into the office space
• Shadings on the east, north and west facades
• Vaulted ceilings that permitted further penetration of light
• Timber louvers that put under control the penetration of light from the western sun of the afternoon.

The light shelves were put on the north façade that in turn led to the creation of a soft indirect light on the space of the roof. The lights have been placed externally and are generated of fabric in a steel frame. The vaulted ceilings permit more natural light that filters to the deeper parts of the spaces of the office. This technique was enhanced by having the windows located at the highest points of the curve. A perforated metal system is utilized in the façade that is facing the east for the purposes of shading which also act as thermal chimney (Li and Lin, 2015).

Heat rises bringing up air through the eastern side of the building permitting that side to be naturally ventilated. The façade that faces the north is made up of steel trellises as well as balconies which support the vertical gardens that are nine stories high. The foliage serves to protect the building from the sun as well as filtration of the sunlight for minimization of the indoor glares. The façade on the west is covered using a system of timber louvers which pivot to maximize on the penetration of natural light as well as views.

These louvers as well serve to protect the façade from the extreme western sun. The amount of sunlight that hits the western façade determines the extent of opening and closing of the louvers which are made from untreated recycled timber and are operated using a computer-controlled hydraulic system. The building as well adopts artificial light all over to offer sufficient amount of light in circumstances where natural light is not present. The lights make use of low energy T5 luminaries that attain a lighting power density of not more than 2.5 watts/m2 for every 100 lux (Shaikh et al., 2014).

Ventilation System

There are shower towers that have been used on the southern façade of the building. Such towers serve to draw the external air from the level of above street and cool the air through evaporation leading to the formation of the shower of water. The cooled air is thereafter supplied to the retail spaces and the water of cool temperature used in pre-cooling the water that comes from the chilled water panels. The towers are normally made from tubes that are of lightweight fabric which have diameters of 1.4 meters. Testing and evaluation done from such towers have shown a reduction in temperature ranging between 4 to 13 degrees Celsius from the upper part of the tower to the bottom of the tower.

The design also incorporated an innovative concept of design through the use of the same quantity of foliage on the buildings as would have been available should the site have still been in the initial natural vegetated state. This is attained through the use of a roof garden which also acts as a break-out as well as a recreation surface for the employees. On the northern façade of the building are incorporated planter boxes that are located west and east of every northern balcony (Shaikh et al., 2014).

The main ventilation used in the building was displacement ventilation. The benefits of the use of displacement ventilation system are such as an enhancement in the cost effectiveness during operation, higher flexibility, enhanced quality within the occupied zone, larger efficiency of operation. The minimum requirement of fresh air in the building was 22.5 litres/second/person which is significantly higher than the provision by the Australian Standard of 10 litres/second/person.

The greater turnover rate was picked since studies have established that low fresh air requirements may directly be related to sickness as well as low productivity inclusive of cold and flu. The building interior has been decorated using a range of plant life that has aesthetic purposes and research has established that plants lower the quantity of VOCs in the air (Shirazi et al., 2016). Besides controlling the amount of VOCs with plants, the planners of the building picked on materials which maintain the indoor pollutant at the lowest amounts.

Solar Heat Gain Calculations

Net heat transfer through the window can be calculated using the formula:

Assuming the scenario below:

The total area of the window is 6 ft², the total U value of the window is 0.30 Btu/hr-ft²-F, the total normal SHCG of the window is 0.70.  The outdoor air temperature is 30 F.  The indoor air temperature is 70 F.  The total solar radiation on each of a south exposure is 150 Btu/hr-ft².

Daylighting Strategies

Determine the net heat gain into the building through the south facing window.

The heat loss of the various material components, annual heating energy load, and total peak heat loss as well as the resultant yearly carbon dioxide emissions are shown in the tables below during open and closed window panel periods.

Council House 2 deploys both metaphorical and literal expressions of the intentions of the environment in its entire architectural composition. Nature has been used as an inspiration for the facades that regulate climate, tapered ventilation ducts are integrated with the strategies of day lighting as well as an evocative undulating concrete floor structure which plays a major role in the cooling and heating of the building (Shaikh et al., 2014).

The performance of the design strategies may be enhanced through the use of window panes that are smaller thickness, smaller than 5mm. this would aid in the reduction of the glare that is as a result of the western facing façade of the building.

Insulation of the materials may also be adopted to enhance their thermal performance that would aid in maintaining the indoor environment quality during the seasons of extreme weather conditions of winter and summer.

References

Afram, A. and Janabi-Sharifi, F., 2014. Theory and applications of HVAC control systems–A review of model predictive control (MPC). Building and Environment, 72, pp.343-355

Aghemo, C., Blaso, L. and Pellegrino, A., 2014. Building automation and control systems: A case study to evaluate the energy and environmental performances of a lighting control system in offices. Automation in Construction, 43, pp.10-22

Day, J.K. and Gunderson, D.E., 2015. Understanding high performance buildings: The link between occupant knowledge of passive design systems, corresponding behaviors, occupant comfort and environmental satisfaction. Building and Environment, 84, pp.114-124

Garrison, L.E., Kunz, J.M., Cooley, L.A., Moore, M.R., Lucas, C., Schrag, S., Sarisky, J. and Whitney, C.G., 2016. Vital signs: deficiencies in environmental control identified in outbreaks of Legionnaires’ disease—North America, 2000–2014. American Journal of Transplantation, 16(10), pp.3049-3058

Hong, T., D'Oca, S., Turner, W.J. and Taylor-Lange, S.C., 2015. An ontology to represent energy-related occupant behavior in buildings. Part I: Introduction to the DNAs framework. Building and Environment, 92, pp.764-777

Hong, T., Taylor-Lange, S.C., D’Oca, S., Yan, D. and Corgnati, S.P., 2016. Advances in research and applications of energy-related occupant behavior in buildings. Energy and Buildings, 116, pp.694-702

Hoyt, T., Arens, E. and Zhang, H., 2015. Extending air temperature setpoints: Simulated energy savings and design considerations for new and retrofit buildings. Building and Environment, 88, pp.89-96

Li, M. and Lin, H.J., 2015. Design and implementation of smart home control systems based on wireless sensor networks and power line communications. IEEE Transactions on Industrial Electronics, 62(7), pp.4430-4442

Shaikh, P.H., Nor, N.B.M., Nallagownden, P., Elamvazuthi, I. and Ibrahim, T., 2014. A review on optimized control systems for building energy and comfort management of smart sustainable buildings. Renewable and Sustainable Energy Reviews, 34, pp.409-429

Shirazi, A., Pintaldi, S., White, S.D., Morrison, G.L., Rosengarten, G. and Taylor, R.A., 2016. Solar-assisted absorption air-conditioning systems in buildings: control strategies and operational modes. Applied Thermal Engineering, 92, pp.246-260