An 'Out of this World' Design for University Building.
When the University of Nottingham sought a new research and applications facility to deliver world-leading research in global navigation satellite systems, it was essential that sustainability was at the core of the building’s design. Using thermal modelling, Maber Architects was able to understand what energy savings could be delivered by a design incorporating Tarmac TermoDeck, a system which exploits the high thermal mass of concrete.
When completed in September 2009, the new Nottingham Geospatial building will comprise of research laboratories, testing facilities, industrial outreach and business development, project units, training facilities as well as the offices of national GNSS projects. Sitting adjacent to the renowned ‘green’ Jubilee campus, this new building will form part of the University’s Innovation Park, which includes the Institute of Engineering Surveying and Space Geodesy and the Centre of Geospatial science.
“It was very clear from the University of Nottingham’s design brief for the Nottingham Geospatial building that it should focus on sustainable principles to complement the good environmental performance of existing buildings on the Jubilee campus,” says Nick Keightley, associate director at Maber Architects.
“Even though the East Midland Development Agency funding only required the building to achieve a BREEAM ‘Very Good’ rating, our aim was to achieve a BREEAM ‘Excellent’ rating, as well as to exceed the current 2006 Building Regulations by 12 per cent,” said Keightley.
A clear choice
A key part of the building’s sustainable design is the specification of Tarmac TermoDeck, a unique heating and ventilation system which uses the high thermal mass of concrete to heat and cool a building.
Keightley explains: “When designing this building environmental considerations were of the upmost importance. Therefore to promote energy efficiency and to avoid excessive heat gains and losses, we have incorporated a number of passive design measures, including a biomass
boiler to meet Nottingham City Council’s 10 per cent renewable energy obligation policy. We understood what energy savings TermoDeck could deliver and it plays a crucial part in the sustainability strategy of the design.”
Energy savings were confirmed by thermal modelling of the building’s design undertaken by D3 consultants. Roy Watts, consultant, D3 Consultants explains: “TermoDeck uses significantly lower energy compared to traditional mechanical ducted air systems such as air conditioning and much lower CO² emissions than alternative mechanical ventilated systems.
“Our thermal modelling work indicated that the energy consumption of the university building would be 130 kWh/m²/annum. This is based on energy consumption of heating (47,445 KWhr/y via the biomass boiler and 57,988 KWhr/y via gas) and electricity (154,567 kWh) for the 2000m² building.”
Tarmac TermoDeck carries out their own thermal modelling in order to understand and predict internal temperatures. This demonstrated that year round comfort conditions could be achieved without the use of a large scale, energy-thirsty cooling plant. In the summer Termodeck utilises cooler night-time ambient conditions to pre-condition the concrete flooring units, which offset heat losses during times when the building is occupied. The system uses a high efficiency air handling and heat reclaim unit coupled to the biomass boiler to cope with colder times of year.
TermoDeck in practice
The building comprises of two main elements, a three storey rectilinear pavilion building utilising TermoDeck, and a triangular wedge atrium.
Keightley continues, “Air conditioning was simply not an option for the University due to their emphasis on sustainability. It did not see natural ventilation as a practical solution for a building which undertakes pioneering scientific research and requires a closed environment.
“We have used TermoDeck in the three storey rectilinear block and it fits seamlessly within the design. It is a flexible system which provides a streamlined, minimalist environment as it uses the existing space within the precast concrete flooring, and there are no surface mounted elements such as chilled beams, radiators or intrusive ducts.
“It combines fresh air mechanical ventilation with the thermal mass of hollowcore concrete planks which results in excellent air quality for a good working environment. The biomass boiler heats water entering the air handling core unit, which in turn heats the fresh air entering the TermoDeck precast slab to approximately 22 degrees. The fresh air is ducted through the core of the planks, maximising the heat transfer between the air and the building mass. This modifies the energy stored in the building fabric enabling heating and cooling loads to be offset in an energy efficient manner.
“The TermoDeck system works well with the atrium design of the building as return air is taken back via the atrium to the air handling unit and then the cycle is repeated,” says Keightley.
A thermally efficient building design ensures that the Nottingham Geospatial building will deliver its low energy targets, however further operational savings are possible with effective post-build monitoring once the building is fully occupied.
The Tarmac TermoDeck team carry out post-build monitoring on over eighty of their buildings in the UK and will continue to monitor the Nottingham Geospatial building once it is fully occupied. This will involve fine-tuning of the control set-points and a regular, thorough check of the response of the heating and ventilation plant. This essential ongoing data allows building occupants to monitor how their building is performing against targets, making tweaks or changes where necessary. Tarmac TermoDeck is also able to produce Display Energy Certificates (DECs) with a team of trained engineers.
