Natural ventilation

Brought to you by the CIBSE Natural Ventilation Group 

The success of a naturally ventilated building starts with a good design based on the optimum location and sizing ventilation openings, combined with a control approach that responds to varying driving forces and occupant needs. Considerations include aerodynamic performance of ventilation openings; local environmental conditions; and occupant (indoor air quality) needs. Any incorrect interpretation can lead to inappropriate ventilation strategies, poor indoor air quality, overheating and excessive energy use.

Stream time: 10.15 – 12.45, Tuesday 21st November 2017


Dr Benjamin Jones, Assistant Professor, University of Nottingham;

10:15 - 11:00

TC1 Assessment Methods

Physical assessment I – water bath and air test methods Physical assessment II – wind tunnel modelling including the characterisation of wind and gusts Multiple modes in stacks versus predictions – a comparison between modelling and full-scale building monitoring Hybrid and/or natural ventilation in practice, project cases, what are the experiences?   


11:00 - 11:45

TC2 Mathematical Modelling

Overview of ventilation opening area terminology and how to estimate window effective areas in the absence of manufacturer data Room/building scale mathematical modelling approaches including dynamic thermal modelling, hand calculations/zonal modelling for energy balance, computational fluid dynamics Mathematical modelling approaches for details within a room including assessment of draughts and airflow through floor voids and corridors   


  • Henry Burridge Lecturer, Department of Civil and Environmental Engineering - Imperial College London​
  • Professor Malcolm Cook Professor and Associate Dean, School of Architecture, Building and Civil Engineering - Loughborough University
  • Dr Chris Iddon Design Manager - SE Controls
11:45 - 12:00

Break & exhibition visit

12:00 - 12:45

TC3 Environmental and air quality assessment issues

Weather data: current and future weather scenarios Normal and extreme weather conditions Interpretation of just one simulation of one building using a weather file and getting people to understand what the single weather file actually teaches us; what do; what different weather files for the same location actually teach us? Stochastic modelling – assessing the variation in natural ventilation and Continue Reading »