BLOOMBERG EUROPEAN HEADQUARTER Low Energy building Analysis

Content Details 1.0 Facade System 1.1 Facade Sketch 1.2 Materiality 1.3 Derbyshire sandstone 1.4 Natural Ventilation 1.5 Facade Detail 1.6 Exterior Bronze Fins 1.7 Low-E (Max) Double Glazing 1.8 Material Selection 1.9 Material’s Benefits

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2.0 Lighting System 2.1Natural Lighting 2.2 Integrated Petal-design Ceiling 2.3 Acoustic 2.4 Lighting system 2.5 Benefits of LED Lighting 2.6 Energy Efficiency of LED Bulb 2.7 Luminous of LED Bulb 2.8 Lifespan of LED

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3.0 Heating, Ventilation, and Air conditioning 3.1 Air Flow 3.2 Heating System 3.3 Air Conditioning System 3.4 Natural Ventilation

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4.0 Waste Management 4.1 Water Sustainability 4.2 Vacuum Drainage for WC 4.3 Wastewater Management 4.4 Benefits of Water Sustainability Innovative Solutions 4.5 Recycling of Cooling Tower Water 4.6 Recycling Strategies 4.7 Calculation and Data of Water Consumption of Bloomberg’s Building

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5.0 Post Occupancy 5.1 Sustainability Editor's View 5.2 Building Performance and Datas 5.3 Sun Shading and Orientation 5.4 Ventilation system 5.5 Central Atrium Skylighting 5.6 Waste Management

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1.0 Facade System 1.1 Facade Sketch

Fig 1.1 Facade Design Sketch and Label

1.2 Materiality

1.3 Derbyshire sandstone

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The chunky stone corners and shear walls that form part of the Derbyshire sandstone façade feature almost poche sections just big enough to squeeze into, with thermal doors that allow air to circulate through the structure.

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Fig 1.2 Material Board of facade in Bloomberg London

1. Acrylic fin to level 1 facade cladding 2. Sandstone external facade cladding and used internally for cores cladding 3. Bronze fin facade cladding 4. Coffee brown granite, used externally on ground level facade; internally for flooring to ground floor, cores and lift lobbies across the building Fig 1.3 Picture of Bloomberg’s Building Facade

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1.0 Facade System 1.4 Natural Ventilation

1.6 Exterior Bronze Fins

Fig 1.6.1 Facade of Bloomberg’s Building Fig 1.4 Air Flow diagram in exploded axono

Aluminum is not ideal for interior acoustics because it can cause reverberation, especially in open-plan offices. To counteract this, the project team spaced the petals apart slightly and riveted them to a perforated metal substructure. As sound passes through these openings, it is absorbed by an internal layer of mineral wool insulation, resulting in a Class A acoustic performance rating.

There are 117 of these fins or so called ‘gills’, which is an appropriate term, as they are the building’s way of ‘breathing’, with a section opening and closing depending on exterior conditions to allow air to flow into the building while keeping external noise to a minimum.

The unique complex curvatures of the exterior bronze fins were designed to achieve both the aesthetics and functionality.

1.5 Facade Detail

Fig1.5 Mixed Mode Ventilation Bronze Tins Details Set into this frame are large-scale fins made of bronze – another material selected in response to its prevalent use in this part of London – to create a building that is contextual and classic, yet clearly of its own time. The fins are static and provide solar shading, varying in geometry, density and scale according to aspect, location and exposure to the sun across the individual bays of each façade.

The bronze fins also contain openable panels in the rear face of the blade. When outside temperatures permit, these panels open automatically, drawing fresh air directly into the deep-plan areas of the building. The internal section of the fin contains an acoustic lining that attenuates the external sounds of the city – a constraint that has previously largely prohibited the ability to naturally ventilate major buildings in densely populated urban environments.

Fig1.6.2 Detailed Drawing of the bronze fins

The precise implementation of these shapes contributed to this building receiving a score of 98.5% in design (the highest design-stage score ever achieved by any major office development) and an ‘Outstanding’ assessment in BREEAM, the Building Research Establishment Environmental Assessment Method.

The concept behind the design is a naturally ‘breathing’ façade that enables an optimized and natural ventilation system. The façade opens in accordance with the exterior conditions, and the shape of the exterior fins were designed by simulating the air-flow.

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1.0 Facade System

Fig1.8.1 Performance of type of Low-E glazing window

1.7 Low-E (Max) Double Glazing

Fig1.7 Performance Diagram of Low-E (MAX) Double Glazing

Low-E (low emissivity) is a process of glass coating either hard or soft. Hard coated can only be applied for pyrolytic glass only. The word pyrolytic is used to describe a change brought about by heat.In pyrolytic glass the metallic oxide is added to the glass while the glass is hot.

1.8 Material Selection

Fig1.8.2 Temperature control performance of types of Low-E Window

The Selection of Low-E (Max) Double Glazing as the window material of Bloomberg’s Building because it could keep the building warm and cool, it could control Bloomberg’s European Headquarters in the comfortable temperature as the graph shown the neutral temperature control and insulation performance of Low-E (Max) Double Glazing is just perfect in The coating itself reflects most of the sun's rays before they the central of London. reach the glass. Soft coated using the process of magnetic sputter are cannot be heat strengthened or tempered because 1.9 Material’s Benefits the heat will destroy the coating.

The character of low-e glass are: 1) reduce heat loss through windows And since the coating increase the amount of the sun's rays 2)heat absorbed from sunlight back inside the room. the glass absorbs, it may necessary to heat treat the glass 3) it allow sunlight into a room without letting to escape before installation. Low-E coating are very thin metallic 4) it can resists ultraviolet light, less damage in furnitures coating that reduce visible light transmission by about 5) reduction of glare 10% compared to uncoated glass. This type of glass are 6) high transparency, low reflectivity, and good thermal very helpful to those who want to conserve energy, low e insulating properties. glass can control the transfer of heat through air.

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2.0 Lighting System: Integrated Petal-design Ceiling

Riveted Perforated Metal Substructure As sound passes through these openings, it is absorbed by an internal layer of mineral wool insulation

Fig 2.0 Riveted Perforated Metal Substructure

2.1Natural Lighting

Fig 2.2 Ceiling Metal Panel of LED

Fig 2.1 Natural Lighting of Bloomberg Diagram

Skylights can help buildings to save energy and gain energy.

Firstly, It reduce the daytime lighting - an energy cost that can account for 40% of power consumption in office buildings. Secondly, skylights allow passive solar gain. In addition, research shows that a rooflight area of 15-20% can contribute to an overall reduction in CO2 emissions in the buildings, illustrating that skylights also contribute to a greater environmental good.

The metal petals and LEDs formed a low-brightness system that is calibrated at a reduced output to minimize wattage consumption while still giving Bloomberg’s employees an ideal 300 lux brightness throughout their working space.

2.3 Acoustic Aluminum is not ideal for interior acoustics because it can cause reverberation, especially in open-plan offices. To counteract this, the project team spaced the petals apart slightly and riveted them to a perforated metal substructure.

As sound passes through these openings, it is absorbed by an internal layer of mineral wool insulation, resulting in a Class A acoustic performance rating.

2.2 Integrated Petal-design Ceiling The innovative ceiling panels are an energy-saving integrated system that feature 2.5 million polished aluminum “petals” that save energy by improving the efficiency of heating, cooling and lighting functions. Incorporating 0.5 million LED lights, Equipped with 450,000 LED downlights, the building burns 40% less electricity than typical office lighting systems. Its unique petal design also helps manage acoustics and airflow.

2.4 Lighting system The ceiling panels provide the interior illumination and are equipped with LED downlights. Since LEDs perform best when kept cool, integrating these fixtures into the chilled panels significantly improves their energy efficiency and overall life expectancy. Additionally, the reflectivity of the petals helps diffuse light more evenly throughout the interior while their three-dimensional shape shields eyes from glare.

2.0 Lighting System: Integrated Petal-design Ceiling 2.5 Benefits of LED Lighting

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2.7 Luminous of LED Bulb

Fig 2.5 Benefits Diagram of LED Fig 2.7 Lifespan of bulbs comparison

2.6 Energy Efficiency of LED Bulb

The graph above demonstrates the overall luminous efficiency of different light sources in which LED had outrun the other four light sources. The previous table and bar graph proves that using LEDs for the lighting needs of large building like Bloomberg London significantly reduces the annual electricity consumption, and this cuts down on the annual electricity cost. Because commercial and residential buildings in London or other large urban areas utilize several megawatts of electrical power for lighting, substantial energy saving are realized with the mere substitution of traditional lighting devices by more efficient oncs.

2.8 Lifespan of LED Fig 2.6.1 Brightness and energy use of bulbs comparison

Fig 2.8 Lifespan of lighting technologies in comparison

Fig 2.6.2 Graph of energy use by bulb type

Annual Energy Savings (kWh) in a large building where 100,000 W of Incandescent light bulbs are substituted with LEDs that consume only 20W and produce the same Luminescence.

Maintenance of bulbs can save a lot of cost more because they do not need to be replaced as frequently as traditional light bulbs. LEDs boast 50,000 to 10,000 operating hours.

They also far outlast fluorescent, metal halide, and sodium vapor lights by 2-4 times, and incandescent bulbs by 40 times.To add, LEDs have great dimming capacities and can operate at a virtually any percentage of their rated power (0 to 100%).

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3.0 Heating, Ventilation, and Air conditioning 3.1 Air Flow

One of the more innovative aspects of the design is that the larger, northern building’s expansive, deep-plan floor plates can be ventilated and cooled using natural ventilation.

Outside air will enter the floor plates through the purpose-designed, vertical bronze fins that line the building’s façade and frame the glazing. The fins incorporate acoustically treated vents that open and close to control airflow. From the floor plates, the air will rise up and out of the central atrium.

When building is in natural ventilation mode, is drawn up through the building’s six-storey ramp and out through vents in the roof. Sensors also allow us to adjust indoor airflow in response to how many people are in the building, which will save 600-750 MWh of power per year.

Fig 3.1 Airflow Diagram

3.2 Heating System

3.3 Air Conditioning System Cooling System Water Pipe Released Cold Air Absorbed Hot Air Rain water is used for the cooling system

Fig 3.2 Combined Cooling, Heating and Power Diagram

Fig 3.3.1 Cooling System Diagram

During winter time, heat engine or power station is used to generate electricity and useful heat at the same time.

Trigeneration or combined cooling, heat and power (CCHP) refers to the simultaneous generation of electricity and useful heating and cooling from the combustion of wastes. The waste of the building are used to generate heat by combined heat and power (CHP) plant.

Aluminum is a highly conductive metal, making it the perfect choice for an integrated cooling system. During the summer, the aluminum petals are chilled by water pipes concealed behind the panels. As air from the ventilation system passes through the slotted petals, it is rapidly cooled, providing a low-energy alternative to traditional air conditioning.

Cooling and Heating On-site power-generation center converts gas to power in an efficient system. Then used waste heat to heat and cool the building.

Fig 3.3.2 Cooling and Heating System

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3.0 Heating, Ventilation, and Air conditioning 3.4 Natural Ventilation

The model was used to confirm the CFD analysis, which showed that natural ventilation might not be effective for some floors if they were all linked.

The biggest risk was that the upper floors would become part of the exhaust air pathway for the lower floors. The top floor is divorced from the atrium because it has roof access.

The floor below has its own challenges and has had special treatment; the lower floors work fine.

Fig 3.4.1 Natural Ventilation Diagram

Fig 3.4.4 Window Blade Sensor Diagram

117 window blades are allowed to be opened and closed, reducing our dependence on mechanical ventilation and cooling.

Fig 3.4.2 Fins Facades sectional Diagram

Ventilation is achieved through large vertical wings on the external front of the building are installed at different angles.

Fig 3.4.5 Central Void Design Section

Fig 3.4.3 Mixed Mode Ventilation Bronze Tins Details

When ambient weather conditions are temperate, the building’s bronze blades can open and close, allowing the building to operate in a “breathable” natural ventilation mode. Reducing dependency on mechanical ventilation and cooling equipment significantly reduces energy consumption.

The central void enables a hybrid ventilation system which pulls fresh air into the building through automated bronze fins which open in the façade. This approach is a potential gamechanger, challenging the dogma that a deep floor plate cannot be naturally ventilated in temperate climates. Sensors that monitor both temperature and CO2 levels trigger ‘spot cooling’ of targeted areas when necessary.Another big problem when you have a 30-metre floor plate is the heat gain the air will experience as it moves across the floor.

Natural ventilation might remove much of the heat from the space, but – nearer the atrium – you will need to ensure that cooling is available from the chilled ceiling to limit the heat gain.

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5.0 Waste Management 4.1 Water Sustainability

When coupled with the extremely low water utilization rates of the vacuum flush system, the net overall discharge reduction for the toilets alone is over 80% as compared to a typical office building. As toilets represent the majority of water demand of an office building, the vacuum flush system reduces our overall wastewater flow by 70% as compared to a typical office building (as measured by BREEAM).

4.3 Wastewater Management

Fig 4.1 Water sustainability schematic diagram

The schematic above represents the various flow paths of domestic, potable, and wastewater flows in the Bloomberg building. As shown, sufficient rooftop rainwater, cooling tower, and grey water waste streams are captured and treated and used as flushing water in the toilets. When coupled with the extremely low water utilization rates of the vacuum flush system, the net overall discharge reduction for the toilets alone is over 80% as compared to a typical office building. As toilets represent the majority of water demand of an office building, the vacuum flush system reduces our overall wastewater flow by 70% as compared to a typical office building (as measured by BREEAM).

Fig 4.3 Induced flushing pressures diagram

1) The angular arrangement of the drainage pipework creates pressure potentials. The difference in air pressure is used to transport sewage from toilets to a vacuum unit.

4.2 Vacuum Drainage for WC

2)In idle mode, a semi-vacuum (~0.5bar pressure) is maintained in the system. When flushed, approximately 60-80 litres of air is sucked through the toilets, in turn sucking the contents of the toilet into the system. The water and effluent forms a slug in the system, approximately 5-15m from the WC unit.

The development of vacuum drainage solutions for WCs offers significant water savings over conventional systems. The solution relies on induced flushing pressures in the drainage pipework. The following illustrates the general arrangement of the system.

3)During running, the vacuum pump macerates the sewage, while at the same time generating a vacuum within the drainage pipework and transporting the sewage to appropriate treatment plant.

4)The system as a whole uses between 0.8 and 1 litres of water per WC flush. This is in comparison to more traditional systems that use up to 5 litres per flush.

4.4 Benefits of Water Sustainability Innovative Solutions The benefits of this innovative solution are clear and various

Fig 4.2 Vacuum Drainage for WC schematic diagram

This diagram represents the flow paths wastewater and water flows in the Bloomberg building. As shown, sufficient rooftop rainwater, cooling tower, and grey water waste streams are captured and treated and used as flushing water in the toilets.

1)Elimination of the use of potable water for WC flushing 2) Use of greywater and rainwater only for WC flushing.

3)Cost savings related to water and drainage 4)Preservation of clean water supplies 5)Alleviation of pressures on existing drainage system.

6)Reduced risk of local and regional flooding

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4.0 Waste Management 4.5 Recycling of Cooling Tower Water

There is however a significant quantity of water that is washed-back, to be expelled to drainage in conventional designs. This bleed off is typically around 20% of the total water consumption of cooling towers. These significantly amounts of water were identified as being valuable by-products that could be recycled.

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Recycling Strategies

Fig 4.6 Water Cooling System Schematic Diagram

Fig 4.5 Recycling of cooling tower water diagram

The Bloomberg London North building utilises cooling towers for heat rejection purposes from the main chiller and CCHP plant. Cooling towers operate by utilising the effects of evaporative cooling.

Whilst this results in significant increases in associated chiller efficiencies, the towers themselves consume large quantities of water. A lot of this water is expelled to atmosphere, through its evaporation, and is often observable as a plume of water vapour.

The backwash water from the cooling towers will be recycled for use in both the cooling towers themselves, as well as for storage alongside other grey water (which will be harnessed from sources such as hand wash basins and cyclists’ showers).

Grey water storage is located centrally in basement level B3 and will serve other water consuming processes that do not require the use of potable water, such as WC flushing.

T hese significant reductions in the consumption of potable water will ensure Bloomberg London North building delivers sustainability benefits throughout its operational life.

4.7 Calculation and Data of Water Consumption of Bloomberg’s Building

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5.0 Post Occupancy

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Bloomberg’s European HQ claims to be the ‘world’s most sustainable office building’, based on its BREEAM Outstanding rating with a 98.5 percent score. Any claim to a global ‘first’ demands scrutiny. So how green is it really?

5.3 Sun Shading and Orientation

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The elevations have been designed to respond to solar orientation and shading from adjacent buildings. Bronze shading devices on each vary in number, scale, pitch and orientation. Along the south-facing Cannon Street façade, additional horizontal brise-soleil screen out peak sun angles.

Though not innovative, this is all too rare in commercial office buildings.

5.4 Ventilation system

Fig 5. 0 Hattie Hartman Portrait

5.1 Sustainability Editor's View Name: Hattie Hartman Occupation: Sustainability editor of, The Architects’ Journal Hattie joined the AJ in 2006 and created the role of sustainability editor in 2008.

5 .2 Building Performance and Datas

The central void enables a hybrid ventilation system which pulls fresh air into the building through automated bronze fins which open in the façade. This approach is a potential gamechanger, challenging the dogma that a deep floor plate cannot be naturally ventilated in temperate climates. Sensors that monitor both temperature and CO2 levels trigger ‘spot cooling’ of targeted areas when necessary.

5.5 Central Atrium Skylighting The bronze fins also contain openable panels in the rear face of the blade. When outside temperatures permit, these panels open automatically, drawing fresh air directly into the deep-plan areas of the building. The internal section of the fin contains an acoustic lining that attenuates the external sounds of the city – a constraint that has previously largely prohibited the ability to naturally ventilate major buildings in densely populated urban environments.

5.6 Waste Management Fig 5. 1 Bloomberg’s Building Performance graph

Fig 5. 2 Bloomberg’s Building Performance table

In order to lead the sustainable principles of the project, the design team for Bloomberg London North building recognised the need for achieving better and more efficient water usage systems ,in order to reduce the consumption of potable water. Tothisend, a number of innovative solutions were developed and specified, including Cooling Tower Water Recycling.

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(n.d.). Retrieved from https://www.bloomberg.com/company/press/bloomberg-most-sustainable-office-building/ (n.d.). Retrieved from https://www.bloomberg.com/impact/?utm_medium=sustainability&utm_content=site-partner&utm_sourc e=site-partner&utm_campaign=MKTG_2019ImpactReport_3BL 15 November, 2017 B. J. A. (n.d.). Building study: Foster ramps it up at Bloomberg. Retrieved from https://www.architectsjournal.co.uk/buildings/building-study-foster-ramps-it-up-at-bloomberg/10025229.a rticle 26 September, 2018 B. J. A. (n.d.). RIBA Stirling Prize 2018: Bloomberg London by Foster Partners.

Retrieved from https://www.architectsjournal.co.uk/buildings/riba-stirling-prize-2018-bloomberg-london-by-foster-partne rs/10035461.article pdf. (2015, April 11). Bloomberg London - North.

Designing a natural ventilation strategy for Bloomberg's central London HQ. (n.d.). Retrieved from https://www.cibsejournal.com/case-studies/designing-a-natural-ventilation-strategy-for-bloombergs-centra l-london-hq/ Gallery of Bloomberg's European HQ / Foster Partners - 38. (n.d.). Retrieved from https://www.archdaily.com/882263/bloombergs-european-hq-foster-plus-partners/59ef740ab22e38649800 03a6-bloombergs-european-hq-foster-plus-partners-sketch-c-norman-foster?next_project=no Nastu, J. (2017, November 22). Bloomberg HQ Is World's Most Sustainable Office Building. Retrieved from https://www.environmentalleader.com/2017/10/174456/ Spears, E. (2019, July 29). Benefits of LED lighting. Retrieved from https://www.hornsbyelectric.com.au/benefits-of-led-lighting/