Natural Ventilation e-stack

The e-stack natural ventilation system provides low energy ventilation systems, using the principles of natural mixing ventilation in winter and natural upward displacement ventilation in the summer.

The e-stack system uses technology filed for patent by the University of Cambridge which is designed to ensure a minimum rate of air change between a building and the exterior in Winter to comply with Part F of the building regulations, whilst minimizing the heating energy required. This is achieved by mixing the incoming cold fresh air in Winter with hot interior air prior to it reaching the occupants. The system ensures that the air quality remains very high but also that the building is totally comfortable to avoid the risk of cold draughts which are often associated with natural ventilation systems.

In warmer weather the system typically operates with higher ventilation flow rates in order to minimize the risk of overheating, although it can be used in conjunction with thermally massive building types to exploit the benefits of passive night-cooling in which case lower ventilation rates are again used.

Data collected shows how the e-stack system provides a much better quality environment in winter. Over a two week period in winter 2008, we turned the e-stack system off on Tuesdays and Thursdays and observed considerably higher CO2 levels as a result of inadequate ventilation. Under normal e-stack operation children aged 5-6 are in the classroom wearing just their school jumpers close to the vent.