Passive ventilation and cooling

Back to 2015 Symposium Overview

Session 16 Paper 2, University College London, 16-17 April 2015

Download full paper using download links above or download slides

The Houghton Primary Care Centre is the first BREEAM outstanding health care building in the UK. This paper explains how the fundamental design principles of natural ventilation and thermal mass have been used in a novel way to provide a low energy building but which also has superb internal conditions both in winter and summer. The building was constructed with a thermal wall running down the spine of the main circulation zone. This feature is core to the building, and serves an underground plenum too which aids distribution of pre-cooled air during summer days. The thermal wall is cooled at night using natural ventilation during the summer in order to create a passive cooling system for use in the hottest portions of the hotter summer days.

The ventilation strategy is completely different in winter, where the thermal wall is not used at all for the main space. Instead, a natural ventilation mixing strategy is used in the main circulation zone. This strategy uses the internal gains in the building to help mitigate the risks of cold draughts. We present experimental data collected from the building, as well as temperatures and air quality measurements recorded with the building in operation. We show how the air pathways change as a function of different temperatures within the main building and thermal wall, and how these need to be accounted for in the modelling of these types of structure.