NHS Sunderland planned to build a new primary care centre that would feature large public spaces, a café, waiting areas and patient and consulting rooms. Working with the PCT, Breathing Buildings was asked to develop a design strategy for natural ventilation, particularly in the public areas, but also in other spaces around the building.
A challenging brief was given by the PCT, stating that the interior temperature of the new building must remain below 25°C for all but 100 hours a year in order to ensure patients and staff are kept comfortable at all times. Traditionally, this would have been achieved through the use of mechanical ventilation and air conditioning. The objective of the design team at Houghton-le-Spring, however, was to create an innovative, low-carbon solution for summer cooling through the use of natural ventilation and thermal mass.
Breathing Buildings designed a bespoke 50m-long thermal wall which was constructed along the spine of the building. This provides ventilation for the consultancy rooms as well as the open-plan waiting area and café. The wall itself is split into 49 individual shafts to separate the ventilation for individual spaces and therefore reduce the potential for the transfer of infection.
In order to optimise comfort and energy savings, different strategies have been applied for summer and winter ventilation. In summer the thermal wall is used to passively cool incoming air. Cold air is drawn down the shafts into the wall during the night and the cooled shafts are then used to reduce the temperature of the warm outside air, which is brought back into the building the following day. In winter, a mixing ventilation strategy is used, utilising the thermal wall for the consulting rooms and six unique e-Stack R-series units from Breathing Buildings for the open-plan areas. It works by bringing cold air into the building from outside, then diluting it with recycled warm air within the building.
Commenting on the solution, Andy Mackintosh, director at construction company, Willmott Dixon, said: “We are delighted how the whole team has worked together to achieve this BREEAM ‘outstanding’ rating. This is the first healthcare project in the UK to do so.”
Shaun Fitzgerland, managing director of Breathing Buildings, added: “We are delighted to have been chosen to be involved in this project and to have played a part in the achievement of the industry-first ‘outstanding’ BREEAM rating.”