A natural ventilation specialist has worked in close collaboration with the design consultant and architect, and other members of the design and construction team to create a zero carbon cafeteria. Breathing Buildings' Costa coloured e-stack ventilation units can be seen on the roof

The new ‘eco-pod’ at Wrekin Retail Park, Telford, has been designed in partnership between Costa and property experts Hammerson, which own the park. The ‘eco-pod’ includes multiple energy saving features, such as a roof mounted photovoltaic array, a heat pump coupled to an underfloor heating and cooling slab, and an e-stack ventilation system.

Breathing Buildings was appointed to provide design consultancy and implementation of a bespoke ventilation solution with a customised control system. The objective of the project was to build a zero carbon retail building whilst ensuring high quality internal conditions to satisfy stringent client requirements.

With large areas of glass requiring management in terms of seasonal heat gains and losses and the added element of continuous foot fall and doors frequently open, this was no small task. A key feature of was to create intelligent, integrated communication systems and controls across ventilation, underfloor heating / cooling, and air conditioning. This ensured all components worked effectively together, rather than against each other.

The innovative e-stack ventilation system works in one of two modes: displacement ventilation in summer and mixing ventilation in winter. The system delivers two energy savings for the building: The first, as with all natural systems, is the significant reduction in fan power over mechanical systems. The second, unique to the e-stack approach and not traditional natural ventilation techniques, is the removal of pre-heating achieved by bringing air in at a high level and mixing it with air in the room, rather than passing it over heating batteries. Both these elements present significant energy savings, contributing to the overall goal of a net zero building.

Additionally, as with all natural ventilation systems, the make or break of success is the control. The sophisticated control system inside the e-stack units ensures the internal air is kept fresh. The on board controller allows the system to monitor temperatures and CO2 levels and react according to demand.

Shaun Fitzgerald, Chief Executive Officer of Breathing Buildings comments: “The key to this project is how all the different elements use a central control system which issues signals based on the temperature and therefore which component is best placed to maintain the interior temperature and air quality. For this type of control system to be installed it was critical that all the contractors worked collaboratively throughout the project to achieve a seamless installation and optimal operative conditions going forward. We are extremely proud to have played an important part in creating the UK’s first net zero energy retail building.”

Simon Kirton, Architectural Director, Emission Zero, concludes: “This project has been designed to be the first zero energy retail building in the UK and marks a significant achievement for Hammerson, and all of the partners involved in developing this unique and exacting project.”