Search in book...
Toggle Font Controls
Create new playlist

Name your new playlist

Playlist description (optional)
Sign In

Email address

Password

Forgot Password?

or

Continue with Facebook

Continue with Google
Sign Up

Full Name

Email address

Confirm Email Address

Password

or

Continue with Facebook

Continue with Google

Chapter 6
Environmental Services

Michael Beaven¹, Miles Keeping², David Pearce¹ and David Shiers³

¹Arup Associates, London, W1T 4BQ, UK

²Hillbreak Ltd., Buckinghamshire, HP18 9TH, UK

³School of the Built Environment,, Oxford Brookes University, Oxford, OX3 0BP, UK

Environmental or Building Services systems and equipment must deliver comfort and amenity to the users of property through carefully designed heating, cooling, ventilation, good air quality, lighting, power, telecoms, IT, security systems, water supply and drainage.

Building services are an important part of building design and can account for 30% of the capital cost and 50% of the running costs of a typical UK office building (BSRIA, 2012). Moreover, building services should never be seen simply as mechanical and electrical kit which can be ‘bolted-on’ to a building, but must ever be seen as integral to a successful, economic design strategy, to be carefully considered at the outset of the design process.

The Building Services Research and Information Association (BSRIA) has published an excellent series of guides which explain the principles of mechanical and electrical building engineering and can be referred to when reading this chapter.

The design of Building Services and choice of appropriate systems is determined by a range of factors including:

Planned-for capital and running costs.
Specific use of the building for example general purpose office space, laboratory, commercial kitchen and restaurant, sports use, auditoria and so on.
Location of the building that is if in an urban centre, there may be pollution and noise issues.
Available plant space within the planned-for building including access for maintenance and replacement. For example, in a simply serviced office building (radiators and opening windows plus some mechanical systems for some internal rooms) the space required would be 6–10% of the total floor area. In a highly serviced building, 15–30% of the floor space would be needed for services (Ibid.).
Noise and acoustic considerations for example within a lecture theatre or concert hall.
Level of energy use for reasons of carbon reduction targets.
Level of control required, that is close, immediate control via a full air conditioning as opposed to natural ventilation systems which respond more slowly to changes outside and inside the building.
Level of comfort required.

Source:

BSRIA

Predicting the conditions under which building occupiers will be comfortable in terms of temperature, ventilation rates, air movement and humidity levels and so on can be a complex and demanding challenge as an individual’s perceptions and preferences can vary widely according to gender, metabolic rate, geographical location, the tasks performed, the clothes worn and the temperature of the surrounding surfaces in a specific situation.

Most guidance states that if, according to occupier surveys and/or the use of a predicted mean vote (PMV) system, at least 80% of the building occupiers are comfortable, then an acceptable standard has been achievedhttp://www.designingbuildings.co.uk/wiki/Thermal_comfort_in_buildings http://www.designingbuildings.co.uk/wiki/Predicted_mean_vote http://auworkshop.autodesk.com/library/building-science/human-thermal-comfort https://en.wikipedia.org/wiki/Thermal_comfort.

The ideal level of thermal comfort for most people doing normal office-type activities is normally predicted to be around 22 °C, ±2°. For activities involving physical effort, the bottom of the temperature range drops to 16°. However, it has been found that in basic, non-air-conditioned buildings, people will adapt to seasonal changes in temperature and that the acceptable internal temperature can be as low as 18 degrees in the winter and as high as 28° in the summer. Similarly, humidity levels are often between 40% and 60% in highly serviced buildings, but may be as wide ranging as 30–70% in basic buildings at different times of the year (www.cbe.berkeley.edu/comforttool).

The ways in which individuals perceive ‘comfort’ in naturally ventilated buildings, has become a field of study in its own right. It has raised a number of issues including the need for the occupiers to be less ‘passive’ compared with the way they might have behaved in older, fully air-conditioned buildings where temperature and ventilation could be changed by simply altering the settings on a control panel (http://escholarship.org/uc/item/2pn696vv#page-1).

Building occupiers experiencing discomfort as a result of temperature, humidity or air quality will not only be distracted from their activities, but may also develop stress-related conditions, physical or psychological problems which will result in lower levels of productivity and higher rates of absenteeism. Building occupier comfort is now the topic of much research and of very great interest to both building owners and businesseshttp://www.hse.gov.uk/temperature/thermal/managers.htm http://www.eci.ox.ac.uk/research/energy/downloads/40house/background_doc_c.pdf http://www.sciencedirect.com/science/article/pii/S0378778812003027http://ibe.sagepub.com/content/20/5/511.short http://www.emeraldinsight.com/doi/abs/10.1108/14725960310807944.

As discussed in Chapter 5, energy use in buildings has become one of the most important issues in building design.

To help designers deliver lower energy buildings, BSRIA have set out five basic energy efficiency strategies, relevant to most building types:

During warm weather, solar heat gain (the sun’s rays heating up the internal spaces of buildings) should be minimised through the use of external shading or tinted glass and the careful consideration of the orientation of building’s facades. Each elevation of a modern ‘green’ building may vary considerably in its design configuration, amount and type of glazing and the type of materials used.
In winter, solar gain and heat gains from the building’s equipment, lighting and so on can be used to heat the building.
Natural ventilation should be used wherever practical constraints allow. Deep floor plans (over, say, 15 m) and high levels of internal partitioning can interfere with the efficient flow of air by natural convection. Where sufficient cooling cannot be achieved by natural ventilation, mechanical fans moving ducted air around the building can provide a ‘mixed mode’ system which requires less energy than full air-conditioning.
Where the functional requirements of the building allow, the use of the outside air to provide cooling is preferable to the use of refrigeration plant; this is known as ‘free cooling’.
Where possible, the amount of daylight entering the building should be maximised to reduce dependency on artificial lighting.

[https://www.iea.org/publications/freepublications/publication/buildings_roadmap.pdf]

In United Kingdom, the most simple heating systems consist of a boiler (normally fuelled by gas, diesel or oil), distribution pipework through which the hot water from the boiler is pumped around the system and the source of the heat output into the building, the ‘emitters’ (most commonly in the form of radiators). There are different types of boilers including condensing and dual fuel (which can use a combination of gas and oil) and, as discussed in Chapter 5, biomass boilers.

Panel radiators (usually made from steel and including a thermostatic control valve) are still a popular choice to provide a simple heating solution to homes and those commercial properties where opening windows can provide ventilation or where mechanical ventilation is installed.

Although the term ‘radiator’ implies that heat is transmitted via radiation, in fact, a large proportion of the heat is distributed by convection.

Convector heaters, like radiators, use pumped hot water, but rather than circulating in a steel panel, the hot water passes through a finned hot water pipe.

Underfloor heating has become more common in recent years, having proven to be an efficient and unobtrusive system in kitchens, bathrooms and certain types of public space including foyers and shopping centres. Most underfloor heating systems use either hot water pipes or embedded electrical elements within the floor structure. They are not a popular choice in office buildings as the underfloor zone is often required to provide data and power supplies to work stations and may also mean the use of raised floors.

In large spaces such as warehouses, sports halls and factories, high-level radiant heating is often used, leaving the floor space unobstructed and the heating units less likely to be damaged by the activities carried out within the space. These emitters directly warm the occupants by radiation without having to heat up the surrounding air which would be cooled by air entering the space through large doorways.

These units can be gas-fired radiant tube or warm air heaters, use hot water panels or strips or can be electric-powered quartz.

See high-level hot water radiant strip heating in factories, high-level warm air heaters with flues and so on at: http://www.powrmatic.co.uk/products/heating/browse/

The natural ventilation of buildings is the preferred option if practically possible, as it is the easiest to maintain (no mechanical moving parts) and does not incur financial or environmental costs through energy use. Natural ventilation can be achieved by the use of simple opening windows in a single sided or cross ventilation arrangement or can use ‘stack ventilation’ which works by using the natural effects of temperature differences within spaces.

See diagrams at:

These diagrams explain the use of stack and wind ventilators (sometimes fan assisted) which can bring ducted fresh air or remove stale air to or from any part of the building.

High-level Chilled Beams are also commonly used in green buildings and utilise pumped cold water to cool ceiling level warm air, causing it to fall back into the space below due to its negative buoyancy.

However, some internal spaces, because of their design, location or use, require additional, mechanically assisted heating, cooling and ventilation.

In many factories, underground car parks, kitchens and in the internal toilets and bathrooms of commercial buildings, mechanically assisted air changes are necessary if ventilation requirements under the Building Regulations are to be met.

As well as providing ventilation, mechanically ducted air is also used to supply filtered heated or cooled air to internal spaces within buildings. These systems can range in complexity from simple warm air units mounted on walls or on ceilings to complex installations of air handling equipment, often found on the roofs of larger buildings.

Fan coil units require only fresh air and a hot/chilled water supply can be used to meet the heating and cooling needs of individual spaces. They are a flexible alternative to large air handling systems (https://en.wikipedia.org/wiki/Fan_coil_unit).

Full air conditioning is used where the demands of the geographical location (i.e. extreme climatic conditions), the site (noisy and/or polluted city centres), or the building’s size, height or use mean that the internal conditions must be wholly controlled. Air conditioning means that the building (or parts of it) is treated as a ‘sealed box’ where the incoming air is filtered, humidified and cooled/heated and where stale air is extracted to be cleaned and reused or released back to the outsidehttps://www.youtube.com/watch?v=t0sjFKPdvIc https://en.wikipedia.org/wiki/Variable_air_volume https://www.youtube.com/watch?v=YCogTVa3XOw.

There are several generic types of air-conditioning system, many of which involve complex technologies, large plant rooms in basements or on roofs plus high capital and running costs. However, these systems offer immediate control of internal environmental conditions, either by the use of individual space sensors or by allowing individual control of temperature, humidity and ventilation rates.

Whilst domestic heating systems may be controlled by simple thermostats and control panel settings, the complex environmental systems in modern commercial buildings require sensors to monitor internal conditions and data handling software.

Building Management Systems (BMS) are networked digital control systems usually having at least one operator terminal. Graphic displays linked to room sensors show the temperature, humidity, occupancy levels and ventilation rates of individual spaces as well as energy consumption data. Such terminals can be located at remote locations such as a company HQ if desired (https://en.wikipedia.org/wiki/Building_management_system; https://www.youtube.com/watch?v=rCjoCoclwoc).

In recent years, digital software has been developed to incorporate BMS into Integrated Building Management Systems. These tools not only control the building’s environmental systems, but can also be used to record a range of security, maintenance, fire precaution status and even procurement data, to inform building owners and to prompt Facilities Managers on the need for action (https://www.youtube.com/watch?v=−9_n3gy7Fc0).

For information on thermal insulation materials and technologies including argon gas and vacuum systems and so on, see:

For information on low-energy lighting and design, see:

For information on Retrofitting and upgrading the environmental systems of existing buildings including historic properties, see:

For information on user behaviour and managing change (e.g. full AC vs natural ventilation systems), see:

For information about the techniques and materials used in United Kingdom’s first BREEAM Outstanding office building at 1 Angel Square, Manchester, see:

Sustainable Drainage Systems (SUDS)

Rather than using the traditional combined or dual drainage systems whereby rainwater from roofs, roads and hard standings and wastes from WCs, baths and basins, are drained by main sewer to treatment plants to be cleaned and returned to rivers or the sea, SUDS either captures water for irrigation or allows it to seep back into the ground via permeable materials built into the landscapehttps://en.wikipedia.org/wiki/Sustainable_drainage_system http://www.susdrain.org/case-studies/case_studies/surgery_kington_herefordshire.html http://www.fangornlandscapes.co.uk/suds.html.

To see an existing housing scheme with a new SUDS, go to https://connect.innovateuk.org/web/sustainable-drainage-systems-suds/article-view/-/blogs/5486115.

For diagrams of typical Combined, Dual and other common drainage layouts and systems, see:

http://www.draindomain.com/system%20layout.html

Environmental Services Case Examples

Citi Data Centre, Frankfurt, Germany; Sky TV Studio, London, United Kingdom.

Citi Data Centre, Frankfurt, Germany: a low-carbon, LEED Platinum solution to the problem of high-energy use.

The Information and Communications Technology industry produces around 2% of all global emissions (Gartner, 2008). Data storage centres are normally huge sheds full of heat generating servers, but by rethinking conventional approaches, the designers of the Citigroup Data Centre created a high-tech workplace, surrounded by large open spaces and gardens.

Illustration of a data center surrounded by lush, open spaces.

Built at Am Martinszehnten, 10 km from Frankfurt city centre, the original brief was not for a sustainable building. Citigroup’s initial requirement was for a robust, efficient, well-engineered property, the received wisdom at the time being that it simply wasn’t possible to make energy-hungry data centres low carbon. However, the client was committed to the principles of Corporate Responsibility demanding carbon reduction targets. In order to help the client to achieve this, Arup Associates led on the idea of making the project low environmental impact and to take on the challenge of designing and delivering the world’s first LEED Platinum data centre.

By using advanced energy systems and forward-looking IT strategies, this data centre takes up only 30% of the power normally needed to provide cooling in such facilities, using only ‘recovered’ energy to provide space heating to the loading facility and the 1500 m² of offices. Water cooling is a major consumer of energy in data centres, and so by installing a reverse osmosis system, it was possible to recover some 90% of all waste water, saving some 35 million litres of water each year.

Putting sustainability at the heart of the project, the team also brought the building within the budget and within the required tight delivery programme.

Floor Area: 230,000-square-foot/21,270 m² of data centre and office accommodation.
Budget: 170 mn Euro.
Due to the demanding programme, the scheme was designed to be delivered in two phases. The agreed phasing path provided 50,000 ft² of gross data area plus all the ancillary space for Phase I and the scheme was delivered in February 2008. For Phase II, a further 50,000 ft² of gross data area remained as an empty shell, without floors, ceilings and so on but with fire detection and sprinklers installed for fire safety until completion in 2010.

Whilst reducing the power loads of a data centre building was, perhaps, the main challenge for the design team, both the client and the consultants were also committed to achieving the best overall ‘green score’ against LEED criteria.

In terms of power consumption for building services and carbon emissions, a typical data centre of this size would be expected to use around 400 MWh/year and produce around 46,000 tonnes of CO₂/year. Arup and Citigroup set themselves targets of a 70% reduction in power consumption and 25% reduction in carbon dioxide emissions; highly demanding, but they deemed them as achievable targets within pre-existing cost and programme constraints.

The original budget had been for a non-green building, so, projected construction costs were closely monitored throughout the design process. Arup kept to the same level of fees even though this new approach required more work. Fortunately, as an integrated design practice, architecture, building services and structural design were developed in a holistic way in order to achieve the requisite value engineering.

For the design team to achieve their green objectives for such a building, they were required to re-evaluate and re-design many of the technical systems commonly used in most data centres, including the design of the cooling towers, the static, lead acid batteries normally used and the computer room air conditioning (CRAC) plant.

At the same time, Citigroup’s IT engineers had to review and, in some instances, re-think the ways in which data centres were fitted out and operated. This would include considering the extensive use of new, energy-efficient, virtualised technology built into special modular cabinets to reduce heat gain within the building and the amount of cable space needed. This questioning of established practices would lead to a reduction in cable use by some 250,000 km.

Although both the designers and the client were aware that all innovations carry a degree of risk, the reliability of the energy supply and the operational efficiency of the data centre remained paramount in all technical decisions taken. A Diesel Rotary Uninterruptable Power Supply (DRUPS) providing the necessary energy supply backup system would hence be a pre-requisite, as would be the use of cooling towers in order to keep the servers at the required temperature.

The overall mass and large areas of facades which enclose the modern data centre can have significant visual impacts and both the designers and the local planning authority were keen to find ways to mitigate them.

The building utilises both natural ventilation and air conditioning systems and is, therefore, a ‘mixed mode’. In data centres, air-conditioning equipment and cooling towers are a necessary requirement for which there are, to date, no practical alternatives.

The design of most conventional cooling towers requires high levels of water consumption. On this project, Arup’s engineers utilised a reverse osmosis system; this uses less water, does not rely on salt and water softeners to be added to the water supply and does not need the same amount of the chemicals required to combat legionella.

Used primarily to obtain drinking water from sea water, reverse osmosis is a water purification process which, if used aptly, can not only reduce water consumption but also assist in heat recovery. In its cooling processes, the Frankfurt data centre estimates using 50 million litres of water per annum less than a conventional equivalent building.

Whilst the design team led the efforts to improve the building and plant performance of conventional data centres, the client had also to review the ways in which the building was to be used.

The Real Estate team from Citigroup was signed up to the idea of a lower energy building from an early stage, but to identify opportunities for in-use energy savings, Arup were also required to engage with the Facilities and IT Teams to better understand their operational objectives. As with all construction projects, effective solutions require a thorough understanding of the problems to be solved and are developed through the recognition of and respect for the culture and priorities of the other stakeholders.

Most data centres operate using all the servers all of the time. In this project, the designers and the IT Operations team reviewed this practice and instead opted for fewer servers working at a greater capacity with the remainder kept on ‘standby’ mode. Similarly, as the Operations and IT teams became inspired by the green aims of the project, data handling systems were reviewed leading to the installation of more energy-efficient computer systems.

For example, the design and configuration of the standard CRAC equipment was enhanced and simplified so as to better use the principles of natural ventilation, thereby reducing consumption from 9.3 to 3.3 kW per unit (Figure 6.1).

Scheme for Computer room air conditioning (CRAC) arrangement. — **Figure 6.1** Computer room air conditioning (CRAC) arrangement.

Conventional data centres use batteries to store energy in case of sudden power loss in order to keep operations ticking until backup generators operate. Here, rather than use batteries, a flywheel feeds energy back to start up the generators. In buildings of this type, batteries use approximately 5% of the building’s energy, but, as this system needs only around 0.5%, there is a significant saving in energy.

In the 1500 m² office space, the accommodation is naturally ventilated, utilising a chilled ceiling. Heating in the offices and in the loading areas is provided by heat recovered from the data centre.

Arup and the Operations team initiated many other measures like these, driving down energy consumption within the building to 30% of that used by a traditional data centre and improving the power utilisation efficiency (PUE) factor from a norm of 2 down to 1.2.

Overall, the building saves 11,750 tonnes of carbon a year which is the equivalent of 500 people’s total carbon footprint. If all the world’s data centres did this, enough power would be saved to power a country the size of Belgiumhttp://www.arupassociates.com/en/case-studies/citi-data-centre/http://thoughts.arup.com/post/details/292/bring-data-centres-in-from-the-cold http://inhabitat.com/citi-data-center-leeds-germany-to-a-green-future/http://www.arup.com/news/2013_09_september/19_september_data_centre_obtains_the_first_leed_gold_certification_in_spain http://publications.arup.com/publications/u/ukmea_sustainability_report http://www.building.co.uk/arups-low-energy-citi-data-centre/3130455.article http://www.e-architect.co.uk/frankfurt/frankfurt-data-centre https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/542558/Consumption_emissions_May16_Final.pdf https://www.theguardian.com/environment/2015/sep/25/server-data-centre-emissions-air-travel-web-google-facebook-greenhouse-gas).

Not only does the Frankfurt centre reduce carbon, costs, emissions and the technical plant areas, it achieves improved statistical reliability due to the reduced plant items needed.

The scheme’s short programme time meant that very high levels of prefabrication and regularity in the structural grid used were required in order to reduce the number of different structural elements needed.

The potential visual impacts of the scheme were addressed in part by providing green roofs to the two-storey offices, the main data centre and the loading area, the planting from which then covers a 55 m long, 12 m high ‘green wall’. Deciduous trees, hedges and wire mesh fences covered by creepers, further soften the visual impact of the building, whilst the main mass of the buildings is set back from site boundaries and buffered by gardens.

In Germany, many consumer materials are produced in the context of a low-waste, low-environmental impact, high recycling-rate culture. Building Codes and Regulations too are part of a responsible approach to the quality and assembly of materials, and standards are high and hard to meet. However, the contractors and legislators knew relatively little of the LEED requirements in terms of material procurement or construction. In order to adhere to the LEED materials Chain of Custody and procurement/disposal tracking needs, the construction and procurement teams needed to adopt different practices and the requirement for LEED procurement protocols was written into the building contract. In the final construction, all materials met the LEED low-VOC, recycled content (27%) and local sourcing targets (40%+). 100% of all construction waste was diverted from landfill.

The project’s construction company has subsequently added this newly developed green procurement expertise to its Environmental Declaration and skill sets.

Illustration of a section showing server floors and green roofs.

Also see:

Sky TV Studio, London, United Kingdom; environmental engineering in the world’s first low-energy TV studio.

Desk space for 1300 staff.
Eight recording studios; subsequently two additional ‘open studio’ areas.
700-server data centre.
23,000 m² of floor space and an approximate building footprint of 100 m × 50 m.
Achieved an energy consumption reduction target of 67% less than a conventional equivalent building.
Completed in 2011.

Sky Studios houses recording, post-production and transmission facilities for Sky’s broadcast and sports news departments, including eight state-of-the-art, naturally ventilated studios, naturally ventilated offices and free-cooled data rooms.

Sky TV’s brief for a genuinely sustainable, flexible HQ challenged Arup Associates to radically minimise energy use throughout, and maintain a clear focus on the human experience of the building. Post-production and technical spaces are positioned centrally, with office space wrapping around the perimeter of the building to allow access to natural daylight and fresh air, as well as views outdoors and across floors.

The building atrium allows visual communication between all levels, providing employees with a sense of scale and location. A cantilevered zone above the entrance contains a series of people-centered spaces, including green rooms, breakout zones, a cafe and meeting rooms.

Initially, the main challenge for the design team was to ensure that energy consumption levels within the building would be significantly less than in a conventional TV studio and broadcasting facility. The normal cooling load for such buildings is in the region of 500 w/m² but studio and office lighting are also heavy users of energy. Compared with a traditional equivalent building, the designers wished to deliver a reduction in energy consumption of around 60%, giving an EPC Rating of ‘A’, a 20% reduction in CO₂ and to derive at least 20% of energy from on-site renewables, as required by the client.

At the same time, there were operational issues for the occupiers and the Facilities Management team which needed to be addressed as part of the briefing process. Many studio staff were more used to the more passive approach to environmental services found in fully air conditioned environments; where heating and cooling control was an instantaneous process triggered by the click of a switch or by a remote BMS.

In naturally ventilated buildings, however, the process is more ‘interactive’, resulting in slower environmental control response time. The design team, therefore, spent many hours developing a clearer understanding of the technical demands of TV operations and also explaining the nature of a green project to stakeholders including TV presenters and the client’s building operations team. This process involved 3 Arup staff for, on average, 12 h per week for 8 months.

One understandable source of concern for the client’s Facilities and Operations team was the absolute need for reliability of the energy supply and the other basic functions of the building. As a broadcaster, Sky TV is a 24-h, 7 days per week international operation, meaning that their buildings must be dependable and able to deliver continually useable studio and office environments.

There were also a number of other challenging technical and space planning issues to be resolved. For example, for cooling purposes, TV studio equipment rooms would ideally be located on the outside of the building. However, office environments in sustainable buildings need good levels of day lighting, and so, ways had to be found to get the benefits of ‘free cooling’ to in-board equipment rooms.

Although the majority of the BSkyB Board and its own engineers were very supportive of the sustainability agenda, some were naturally concerned about the ‘green’ approach and the perceived increased risk of additional time and expense. As part of the project development and management process, the design team had to set aside adequate time and resources for the briefing, explanation and negotiation with stakeholders in order for the project to be a success.

This process would include discussions with the contractors. each of whom would have their own sustainability targets and requirements, including the managing contractor. The managing contractor was to take responsibility for many aspects of the detailed design and they too were to take a careful look at the cost and time implications of some of the technologies being put forward.

During the demolition of the previous building on the site, 90% of the demolition material was recycled and waste targets for the construction of the new studio were also set high at 97% of construction waste being diverted from landfill. 98% of all timber used during construction was to be FSC certified.

The design of the studios was ‘process driven’. In the same way that the design of a concert hall for classical music might start with a careful analysis of the key space planning and technical requirements of an auditorium, an understanding of the function of a TV studio was derived from thorough research supported by client briefings and workshops. The resulting design ideas flowing from that process were then adapted to fit the site.

The BSkyB board was looking for 20% of the energy needs of the building to be generated by on-site renewables. A scoping exercise was carried out examining the practical and economic feasibility of utilising some of the most commonly used forms of renewable energy in United Kingdom:

Photovoltaic (PV)
Ground source heat
Wind
Biomass
Combined heat and power (CHP)

If none of these systems had been suitable, Arup Associates planned to use grid supplied energy from a renewable source such as off-shore wind. ‘Special Uses’ such as TV studio processes are normally ignored in the consumption calculation when looking at Part L Building Regulation compliance models and renewable calculations. However, BSkyB chose to include these to calculate a more realistic energy consumption and use this as the basis of their renewables provision.

Given the requirements of the building type and the constraints of the location, an approach based solely on PV and wind was ruled out on the grounds of practical feasibility and costs. The study also concluded that the installation of a Ground Source Heat system would have delayed the site clearance programme and that the cost-benefit ratio predictions were inconclusive.

The study showed that a biomass fuelled Combined Cooling Heating and Power plant offered the best solution for the project. It would provide sufficient renewable energy to reduce the carbon emissions by the required 20%, enough energy annually to power the equivalent of 3000 homes, and heat 600 homes. Transport impacts too, were an important part of the feasibility study as the raw materials for such a system would have to be delivered to site. However, as the building is located on an edge-of-town site to the west of London with good road links for sourcing materials, the projected environment impacts were within an acceptable range. Arup had been carrying out ongoing research into renewable systems prior to this project and so were confident in suggesting an Austrian-made advanced woodchip system for this building.

At the same time as renewable supply was being researched, the designers were also looking at ways to reduce energy consumption in the building. The challenge for the design team was to design natural ventilation to the high loads created by traditional studio lighting, which was achieved and proven in the commissioning of the studios.

Once the building was occupied, energy reduction strategies were further helped by the introduction of new light-emitting diode (LED) technologies in studio lighting. Alongside recent advances in camera technology enabling images to be recorded at lower light levels, this change has meant reduced energy use and less heat from the lighting systems.

In a sector which is technology-based such as broadcasting, change is often rapid and far reaching. Flexibility and future proofing, therefore, underpinned many aspects of the design of Sky Studios (http://downloads.bbc.co.uk/outreach/BBC_LEL_Guidelines.pdf).

The giant natural ventilation chimneys of the recording studios are revealed on the exterior of Sky Studios leading some to regard the building as an example of a new ‘power station architecture’ for the 21st century.

The building is divided horizontally into three zones: ‘make’, ‘shape’ and ‘share’. Lower floors contain the giant studios within which television content is made. Middle floors contain the data centers, production facilities and editing suites within which the content is ‘shaped’. The upper floor contains the transmission platforms from which the television signal is ‘shared’.

Studios require very close control of external noise. Natural ventilation would appear to run counter to this objective, as noise is normally brought in along with the fresh air. In this building however, the system is driven by the waste heat given off by the studio lights. Hot air from the lights would usually need to be cooled mechanically, but here the air rises out through giant ventilation chimneys visible on the exterior of the building, drawing in cool, fresh, external air below the studios through a series of sound attenuators. Where external conditions are inappropriate for natural ventilation, mechanical ventilation and cooling of the studio spaces can be implemented.

Chiller Units

The design and specification of the chiller units to be located on the roof was identified as being of particular importance in the special context of this building. The client’s engineering team proposed using bespoke manufactured chillers from one of their regular suppliers which incorporated Turbocore compressors using magnetic bearings to reduce maintenance requirements and increase reliability as well as provide higher part and full load operating efficiencies. At the time of design, these were still a comparatively new technology, but showed the client’s commitment to test out and apply new thinking to the design process.

Equipment Room ‘Free Cooling’

The large number of data equipment racks that are provided to support the media facility normally use significant amounts of cooling energy. To reduce the amount of mechanical cooling required, the design team developed a strategy to use outside air cooling. Large low-energy supply fans are located on the roof of the building providing filtered air via large builders work shafts. This air is mixed with the room air via local room units providing savings on mechanical system cooling. Waste heat is rejected using similar low-energy exhaust fans located on the roof.

‘No Gas’ Supply

At the request of the client engineering team, the building is not provided with a gas supply. The initial brief indicated that providing year-round cooling for the building would be required with minimal heating. The design team determined that a minimal heat source would still be required after accounting for free cooling and heat recovery systems. Water-to-water heat pumps assist in providing chilled water for cooling of technical spaces. The waste heat from these is used to provide heating for fresh air systems and façade heat losses.

Domestic hot water for showers and so on is provided using waste heat from the combined heat, cooling and power plant.

Mixed Mode Ventilation

The general workspace office areas of the building are located at the perimeter to allow natural ventilation to be used when external ambient conditions allow. High- and low-level openings are provided within the façade to allow occupants to control personal environmental conditions as required. In the deeper plan office space, a central shaft links each floor allowing additional natural daylight combined with automatically controlled louvres which provide ‘stack’ driven ventilation.

When external ambient conditions are too cold or too hot for natural ventilation, the openings are automatically locked, closed by the BMS. The building air handling plant then takes over providing minimum fresh air ventilation in the winter and enhanced ventilation in the summer. Air is introduced into the space through floor mounted up-flow diffusers, using the generous floor void space which is already provided to cater for the extensive technology cabling systems. Up-flow ventilation allows air to be supplied close to room temperature for both cooling and heating requirements. High floor-to-ceiling heights allow heat to be removed at high level from the space at a higher than normal temperature in the summer. This approach requires less summer cooling compared to ceiling mounted systems which use much lower supply air temperatures.

Post-production and technical spaces are positioned centrally, with office space wrapping around the perimeter of the building to allow access to natural daylight and fresh air and vistas outdoors and across floors. While a BMS optimises the cooling and ventilation of the building, windows can be individually controlled by occupants during a natural ventilation period.

The building atrium allows a visual communication between all levels of the buildings, providing employees with a sense of scale and location, while a cantilevered zone above the entrance contains a series of people-centred spaces, including green rooms, breakout zones, a cafe, and meeting rooms.

There are eight state-of-the-art naturally ventilated studios, naturally ventilated offices for 1300 people, and free-cooled data rooms for more than 700 computer servers.

The client needed the building to be operational for the start of the 2011/2012 Premier League Football Season which led to a challenging construction programme.

A steel frame was chosen to enable rapid erection of the primary frame, with the design being released ahead of following trades to overcome fabrication lead-in time. One of the significant challenges of incorporating studio facilities into a building is how to span the building above over the large studio spaces. The choice of long-span cellular beams, which could span clearly over the studios and provide column-free office space above, avoided the need for costly transfer structures above the studios. The building services can be integrated within the beam depths enabling the floor-to-floor heights to be minimised. This strategy produced a saving of 2 m on the overall building height, equivalent to £0.5 mn off the cladding budget.

The building is also used as a satellite transmission facility, imposing strict sway and rotation limits on the building structure. Steel bracing is provided within the façade to maximise its lever-arm from the centre of mass of the building and hence its efficiency. To minimise the impact on the aesthetic of the façade, this bracing is hidden in stair cores and behind the studio chimneys as they rise up the building.

As part of the need to reduce cooling loads in the building, a high-performance façade system was developed. The design, therefore, had to include areas of solar shading and provide high levels of natural lighting. So, the façade designs are different on each elevation, depending on orientation and exposure. The façade of the building also incorporates motorised, top-hung opening windows as part of natural vent system. Extensive testing was required to be sure that these systems were both quiet and dependable.

Once the design of the façade system was finalised, carefully drafted, detailed performance standards then proved to be effective in delivering this element of the building as originally conceived.

Since completion, the design brief of providing a flexible facility has allowed a continual change in the way the building is used. A second ‘on-floor open studio’ has since been added and further catering facilities included within the Atrium space. ‘Future Proofing’ for BSkyB’s business, indeed for all clients, remains a vital factor in the Arup design process.

Bibliography

BSRIA (2012) Illustrated Guide to Building Services, https://www.bsria.co.uk/download/product/?file=izGNVziWFHU%3D
Beaven, M. and Vincent, J. (2004) Ch. 6 Engineering Intelligence Through Nature , in Intelligent Buildings – Design, Management and Operation , Second edn (ed. D. Clements-Croome ), Thomas Telford.
Gartner (2008) Thought piece on Disruptive Digital Technologies, http://www.gartner.com/newsroom/id/681107 (accessed 2014).
http://www.archdaily.com/382951/harlequin-1-arup-associates/ (accessed 14 June 2017).
http://www.architecturetoday.co.uk/?p=12885 (accessed 14 June 2017).
http://www.arupassociates.com/en/case-studies/sky-studios/ (accessed 14 June 2017).
http://www.worldbuildingsdirectory.com/project.cfm?id=2939 (accessed 14 June 2017).
http://www.e-architect.co.uk/london/harlequin_1_bskyb.htm (accessed 14 June 2017).
http://www.bioregional.com/wp-content/uploads/2016/04/The-BedZED-Story.pdf (accessed 14 June 2017) (page 6).
https://www.bsria.co.uk/download/product/?file=MAikRpUb1Ng%3D (accessed 14 June 2017) (page 7).
https://en.wikipedia.org/wiki/Insulation_(list_of_insulation_material) (accessed 14 June 2017).
https://en.wikipedia.org/wiki/N.O.M.A.,_Manchester (accessed 14 June 2017).

..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.

Table of Contents for Chapter 6: Environmental Services

Create new playlist

Sign In

Sign Up