CIBSE Case Study: Engineering DNA
CIBSE Case Study: Engineering DNA
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Article from the September 2014 edition of the CIBSE Journal written by Steve Berry.
One of the world's largest biomedical research centres is nearing completion in a heavily built-up district of central London. In 1953, Francis Crick, together with his colleagues James Watson and Maurice Wilkins, identified the structure of DNA. This proved to be of significant importance to biomedical research, and earned Crick, Watson and Wilkins the 1962 Nobel Prize in Physiology or Medicine.
In 2015, the institute that bears his name will open its doors to the scientific community. Located opposite London's St Pancras Station it will be an entirely new organisation, with a distinctive vision of how medical research should be conducted. This involves bringing the best minds together and engaging in extensive collaboration between scientists, biologists, chemists and physicists, with the aim of discovering treatments and cures for human diseases and ailments.
The Francis Crick Institute, when completed, will be one of the largest biomedical research facilities in Europe. It is a unique partnership between Cancer Research UK, the Medical Research Council, the Wellcome Trust, University College London (UCL), Imperial College London and King's College London.
As the client's consultant, Arup w as involved in the evaluation of various sites before settling on the institute's final location in 2008. The fi rm was appointed, after a competitive tendering process, to carry out the MEP engineering design, project management, fi re, security and logistics consultancy services.
The 82,000m2 facility, which will house 1,500 scientists and support staff, consists of four basement levels, including two interstitial plant floors, and eight levels above ground, which will contain laboratory, plant, support, administration and amenity areas.
The building is made up of two bars, north and south, which are connected by an eastwest atrium. The bars are further divided by a north-south atrium extending across the building.
The location was carefully evaluated, placing the institute within a cluster of hospitals, educational institutions and learned societies, which are already working on some of today's most important medical research.
The project was conceived as a multidisciplinary, life-science research facility, incorporating primary and secondary shared/dedicated laboratory areas, plus associated write-up areas, biological research facilities (BRF), with high-containment laboratories alongside chemistry and dry-lab functions, together with all the required amenity, administration, auditorium, restaurant and support functions. Each of these elements presents its own particular engineering and design requirements.
The site is landlocked, with the British Library to the south, St Pancras Station to the east, and listed housing blocks to the north and west. Below ground, the surrounding streets are crowded with utilities, including two 120-year-old, low-pressure gas mains.
The area is densely populated and there are two tube lines running underground, close to the site. The subterranean St Pancras Box, which incorporates the St Pancras International domestic rail station, is adjacent to the site, on the east side. Modern laboratory buildings can only accept extremely low levels of vibration transmitted within the building structure, so the project adopted a blanket level of Vibration Criteria-A (VC-A) across all laboratory floors, with local isolation tables in areas, such as the imaging zone, that required more stringent VC-D/E. All MEP plant and equipment that generates vibration must be fully isolated from the structure by means of anti-vibration mountings, spring hangers and supports.
The sophisticated research equipment is very sensitive to electromagnetic emissions, which required the MEP equipment to be separated from any receivers by sufficient distances to eliminate interference. The most sensitive equipment has a further level of protection, with both passive and active shielding provided.
Some research has to be conducted in laboratories with high containment levels, CL3 and CL3+ (the highest level). These are subject to stringent security checks by the Health and Safety Executive and must pass rigorous design reviews, called Hazop analyses, as well as qualitative risk assessment (QRA) for the CL3+ lab. This leads to an array of system component redundancy, and segregated/dedicated plant. The BRF, while not high-containment, is also subject to considerable scrutiny by the Home Office and the Department for Environment, Food and Rural Affairs (Defra).
Very high levels of ventilation are required with 20 air changes per hour. The project also has sophisticated diurnal lighting control, acoustic control and high-efficiency particulate arrestance (HEPA) filtration of the air supplies and exhaust. The BRF also incorporates stringent odour control, which is dealt with primarily by careful architectural design, coupled with ventilation regimes.
Emissions from air stacks carrying exhaust from laboratory fume cupboards, the BRF and the high-containment laboratories, as well as the flue discharges from gas-/oil-fired boilers and combined heat and power (CHP) generators, have been numerically modelled by the project environmental consultant.
Discharges must satisfy both the Clean Air Act and the local authority with regard to contamination levels at local street-level receptor points. To ensure no discharges are returned into the building, a physical model was tested in a wind tunnel. To assess the nature and implications of the many engineering challenges facing the project, a number of studies were undertaken by the engineers and other specialists. See the "Engineering research" box for the full list.
The Francis Crick Institute is the first laboratory, and one of the first buildings of any type, to be subject to the latest (2010) energy regulations, which demand an average of approximately 25% reduction in carbon levels. This was achieved, along with an "Excellent" BREEAM rating.
The sustainable design measures were dictated by the London Plan, as well as Building Regulations. They include shading systems, a 2MVA CHP unit, and 1,700m2 of photovoltaics (see "Sustainable by design" box).
Configuration and architecture
MEP plant and systems have to be functional and adaptable, and fit within the overall architectural form of a building. The brief for the Francis Crick Institute was for it to be aesthetically pleasing, while providing good spatial planning and an efficient working environment. This presented considerable challenges to the architects, because space was constrained and there were stringent planning requirements. The impact of the building's height and massing had to be carefully considered, particularly in relation to nearby housing, which had rights to light.
To a large extent, this drives the MEP servicing strategies. The BRF is all in the 16m deep basement, along with most of the high-containment laboratories. This has meant large interstitial floors are required to accommodate the sizable HVAC and other services required to support these areas.
To restrict and control the potential vibration of the structural-loading impacts of heavy plant, most of this is also located in the basement in its own energy centre.
Air handling equipment requires large fresh air intake, as well as large discharge stacks. (The total fresh air requirement is 430m3/sec, equivalent of emptying an Olympic pool in less than 10 seconds.)
For these reasons, the air handling units (AHUs) are on the upper plant floors. Electrical substations are located at both basement and roof levels, to be close to the main electrical loads.
To distribute services from the plant areas to the occupied floors, large vertical distribution risers were created, running the height of the building. In addition, horizontal primary routes for services connecting between risers at each floor level, as well as providing service feeds to the floor itself, have been created in 1.5m-deep ceiling void spaces.
The general laboratory areas consist of primary, shared secondary, dedicated secondary and write-up areas, based on a 6.2m x 9m structural grid, with adaptability built into the MEP design, to allow future changes driven by the science.
Primary laboratories are main laboratories, which can accommodate a range of different sciences. Shared secondary laboratories contain high value assets, which are used extensively.
Dedicated secondary laboratories are areas containing specific laboratory equipment that is dedicated to a particular area.
The laboratory spaces on the north and south bars are designed to be open, with sight lines between laboratories. They are connected with link bridges and collaboration spaces to facilitate interaction between scientific groups.
The general laboratory areas are designed, from the services point of view, to operate as a Containment Level 2 (CL2) area, with the write-up areas located outside the laboratory.
The general laboratory system is a variable air volume (VAV) system, with supply and extract VAV units located within the structural grid. Within secondary laboratory areas, additional fan-coil units supplement the VAV cooling.
The main contractor, Laing O'Rourke, adopted a pre-assembled modular approach to MEP services because of the size and scale of the project, and because of the constrained site and challenging construction programme.
In addition to the 4,000-plus preassembled MEP modules, a further 2,000- plus prefabricated sections of pipework, containment and valve assemblies have been used in the construction of the MEP systems.
This is in addition to the hundreds of thousands of other MEP products, and devices that have needed to be procured, delivered and installed on a "just in time" basis. A separate article on modularisation and offsite assembly is planned for a future issue.
Francis Crick was noted for his intelligence, openness to new ideas, and collaborations with different disciplines, and all of these qualities were needed by the engineering design team to deliver this groundbreaking project.
A great deal of modelling and analysis was carried out on the Francis Crick Institute before construction began:
- Acoustics and vibration - background acoustics levels and vibration signatures were measured, and then used as the baseline for compliance and mitigation measures
- Electromagnetic compatibility/interference - the profile of the site was assessed in order to establish background levels Environmental studies - a number of studies were performed, including the impact the building would have on existing air quality
- Daylighting - studies were performed to identify the impact the building would have on its surroundings, as well as the extent of natural daylight entering the buildings
- Thermal performance - the building was modelled with IES software to confirm compliance with Building Regulations, supporting the BREEAM assessment
- Dispersion modelling - numerical analysis to confirm that the 32 large extract air stacks and thermal flues are compliant with emissions requirements. In addition, wind-tunnel testing done to confirm emissions would not re-enter the fresh air intakes
- Odour modelling - conducted using both numerical and empirical testing of BRF waste and feed materials on exhaust streams.
- Objective and subjective measures were used to access potential mitigation
- Flooding impacts - assessed based on risk analysis and flood maps
- Computation fluid dynamics - the heat flux in the data centre was assessed under both normal and equipment-failure scenarios
- Lift traffic analysis - Elevate software was used to assess the number, size and location of the lifts.
- Client - Francis Crick (UKCMRI)
- Project manager - Arup Project Management
- Architects - HoK/PLP and BMJ
- MEP engineer - Arup
- Cost consultant - Turner and Townsend
- Structural engineer - AKT
- Main contractor - Laing O'Rourke
- 15 MVA electrical supply capacity
- 7.5 MVA standby generation capacity
- 2 MVA CHP plant
- 300,000 litres diesel fuel storage
- 4 x 4,000 kW water-cooled chillers
- 3 x 6,500 kW steam boilers
- 3 x 3,100 kW LTHW
- 1 MW data centre
- 13 passenger lifts
- 9 goods lifts
- 4 x 3,250 kg liquid carbon dioxide/liquid nitrogen tanks
Sustainable by design
The project needed to satisfy the London Plan, as well as Part L of the Building Regulations.
The London Plan describes an energy hierarchy:
Be lean - energy efficiency beyond the current Building Regulations
Be clean - priority given to connection to district heating networks and cogeneration
Be green - on-site renewable energy generation.
The following were incorporated into the design to improve energy-efficiency measures:
high-performance glazing with shading systems; high-efficiency plant; lighting control and ventilation systems with variable volume flow.
A 2 MVA CHP unit and connections to allow a future integration into a district heating scheme were also incorporated into the design.
In addition, 1,700 m2 of solar photovoltaic panels were incorporated into the southern roof facade to generate energy that feeds into the electrical distribution.